Oglesby v. Baltimore School Associates , 484 Md. 296 ( 2023 )


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  • Jamaiya Oglesby v. Baltimore School Associates, et al., No. 26, September Term, 2022
    LEAD-BASED PAINT – EXPERT OPINION TESTIMONY – SOURCE
    CAUSATION – IQ LOSS – SUMMARY JUDGMENT – Supreme Court of Maryland*
    held that trial court abused its discretion by excluding testimony of plaintiff’s causation
    expert witness in lead-based paint case. In ruling on motion to preclude and making
    determinations as to whether expert’s opinion had sufficient factual basis, trial court
    resolved genuine disputes of material fact, and, in doing so, abused its discretion. Expert’s
    opinion that plaintiff’s exposure to lead-based paint at property was significant contributing
    factor to plaintiff’s alleged injuries (other than IQ loss) was supported by sufficient factual
    basis and admissible, as expert had adequate supply of data from which to form opinion,
    and methodology expert used reliably supported opinion reached.
    Supreme Court remanded case, however, for further proceedings consistent with Court’s
    holding in Rochkind v. Stevenson, 
    471 Md. 1
    , 
    236 A.3d 630
     (2020), for determination as
    to whether methodology used by expert was sufficiently reliable to permit expert to render
    specific opinion that plaintiff’s exposure to lead resulted in loss of IQ points, should
    plaintiff seek to present such evidence at trial.
    Having concluded that trial court abused its discretion in granting motion to preclude,
    Supreme Court also held that trial court erred in granting summary judgment. Trial court’s
    ruling—that plaintiff was unable to prove negligence without expert’s testimony as to
    causation—was not warranted. Plaintiff presented sufficient evidence that property was
    reasonable probable source of exposure to lead and that exposure was significant
    contributing factor to alleged injuries to establish prima facie case of negligence,
    irrespective of admissibility of expert’s opinion as to IQ loss.
    *
    At the time of the grant of the petition for a writ of certiorari in this case, the Supreme
    Court of Maryland was named the Court of Appeals of Maryland. At the November 8,
    2022 general election, the voters of Maryland ratified a constitutional amendment changing
    the name of the Court of Appeals of Maryland to the Supreme Court of Maryland. The
    name change took effect on December 14, 2022.
    Circuit Court for Baltimore City
    Case No. 24-C-18-000268
    Argued: March 2, 2023
    IN THE SUPREME COURT
    OF MARYLAND*
    No. 26
    September Term, 2022
    ______________________________________
    JAMAIYA OGLESBY
    v.
    BALTIMORE SCHOOL ASSOCIATES, ET
    AL.
    ______________________________________
    Fader, C.J.
    Watts
    Hotten
    Booth
    Biran
    Gould
    Eaves,
    JJ.
    ______________________________________
    Opinion by Watts, J.
    ______________________________________
    Pursuant to the Maryland Uniform Electronic Legal Materials               Filed: July 26, 2023
    Act (§§ 10-1601 et seq. of the State Government Article) this
    document is authentic.
    2023-07-26
    14:15-04:00
    Gregory Hilton, Clerk
    *At the November 8, 2022 general election, the voters of Maryland ratified a constitutional
    amendment changing the name of the Court of Appeals of Maryland to the Supreme Court
    of Maryland. The name change took effect on December 14, 2022.
    This case arises out of a plaintiff’s attempt to use expert testimony in a lead-based
    paint case to establish a property as a source of exposure to lead and a significant factor
    contributing to her alleged injuries including a loss of intelligence quotient (“IQ”) points.
    Jamaiya Oglesby, Petitioner, initiated a lawsuit in the Circuit Court for Baltimore City
    against Baltimore Schools Associates,1 Crowninshield Management Corporation, Jolly
    Company, Inc., and the Estate of Mendel Friedman (together, “Respondents”) for
    negligence, negligent misrepresentation, and a violation of the Maryland Consumer
    Protection Act. Ms. Oglesby alleged that Respondents, who owned and managed an
    apartment building (the “property”) in which she lived as a child, were liable for injuries
    she sustained as a result of exposure to lead-based paint at the property. Ms. Oglesby
    designated Sandra Hawkins-Heitt, Psy.D., as an expert in the areas of clinical psychology
    and neuropsychology. Dr. Hawkins-Heitt evaluated Ms. Oglesby and concluded that she
    suffered from cognitive impairments or deficiencies in multiple areas and had an IQ of 80.
    Ms. Oglesby designated as a vocational expert Mark Lieberman, M.A., a Certified
    Rehabilitation Counselor. Mr. Lieberman evaluated Ms. Oglesby and found that she had
    numerous limitations and qualified as a “Cognitively Disabled” person.
    Ms. Oglesby designated Steven Elliot Caplan, M.D., as an expert in the area of
    pediatric medicine to testify with respect to causation. Dr. Caplan reviewed 24 sets of
    records pertaining to Ms. Oglesby, including the reports of Dr. Hawkins-Heitt and Mr.
    1
    Although the case captions in both appellate courts identify the party as “Baltimore
    School Associates,” the parties in their briefs use the name “Baltimore Schools
    Associates.”
    Lieberman, and authored a report setting forth his opinions. Dr. Caplan concluded that Ms.
    Oglesby’s likely exposure to lead at the property was a significant contributing factor to
    bringing about the cognitive deficiencies and impairments found by Dr. Hawkins-Heitt and
    Mr. Lieberman as described in his report, and to a loss of approximately 3 to 4 IQ points.
    In reaching his opinion as to Ms. Oglesby’s IQ loss, Dr. Caplan relied on two studies—the
    Canfield study2 and the Lanphear study3—which conclude, among other things, that, in
    children, there is an inverse relationship between blood-lead level (“BLL”) and IQ.
    Respondents moved to preclude Dr. Caplan’s opinions and testimony, and for
    summary judgment. Respondents contended that Dr. Caplan lacked a sufficient factual
    basis for the opinion that Ms. Oglesby was exposed to lead at the property and that the
    alleged exposure caused her injuries.       In addition, Respondents argued that the
    methodology Dr. Caplan used to calculate Ms. Oglesby’s IQ loss was not reliable or
    generally accepted. After a hearing, conducted remotely, at which the circuit court
    simultaneously considered motions to preclude expert opinions and testimony and motions
    for summary judgment in Ms. Oglesby’s case and a second unrelated case, and a motion
    2
    See Richard L. Canfield, Charles R. Henderson, Jr., Deborah A. Cory-Slechta,
    Christopher Cox, Todd A. Jusko, and Bruce P. Lanphear, Intellectual Impairment in
    Children with Blood Lead Concentrations below 10 μg per Deciliter, 348 New Eng. J. of
    Med. 1517 (Apr. 17, 2003), available at https://www.ncbi.nlm.nih.gov/pmc/articles/
    PMC4046839/ [https://perma.cc/ JV55-68C3].
    3
    See Bruce P. Lanphear, Richard Hornung, Jane Khoury, Kimberly Yolton, Peter
    Baghurst, David C. Bellinger, Richard L. Canfield, Kim N. Dietrich, Robert Bornschein,
    Tom Greene, Stephen J. Rothenberg, Herbert L. Needleman, Lourdes Schnaas, Gail
    Wasserman, Joseph Graziano, and Russell Roberts, Low-Level Environmental Lead
    Exposure and Children’s Intellectual Function: An International Pooled Analysis, 113
    Env’t Health Persps. 894 (July 2005), available at https://www.ncbi.nlm.nih.gov/pmc/
    articles/PMC1257652/ [https://perma.cc/8LT6-NZZQ].
    -2-
    for summary judgment in a third separate case, the court granted both of Respondents’
    motions in Ms. Oglesby’s case. The circuit court found that Dr. Caplan lacked a sufficient
    factual basis for his opinions due to what the court described as “factual issues in both of
    the cases, which [] normally could be presented to a jury” and that, without Dr. Caplan’s
    testimony as to causation, Ms. Oglesby was unable to establish a prima facie case of
    negligence. Ms. Oglesby appealed,4 and the Appellate Court of Maryland5 affirmed the
    judgment of the circuit court. Ms. Oglesby filed a petition for a writ of certiorari, which
    we granted.
    After a careful review of the record, we hold that in ruling on the motion to preclude
    and making determinations as to whether Dr. Caplan’s opinions had a sufficient factual
    basis, the circuit court resolved genuine disputes of material fact. We conclude that Dr.
    Caplan’s opinion regarding Ms. Oglesby’s exposure to lead at the property being a
    significant contributing factor to her injuries, other than IQ loss, was supported by a
    sufficient factual basis and admissible, as Dr. Caplan had more than an adequate supply of
    data from which to form the opinion and the methodology he employed was reliable. As
    such, the circuit court abused its discretion in granting the motion to preclude and in
    4
    The circuit court granted the motion to preclude and the motion for summary
    judgment as to Ms. Oglesby’s claims for negligence and negligent misrepresentation. Ms.
    Oglesby consented to entry of summary judgment as to the claim for a violation of the
    Maryland Consumer Protection Act, so that judgment would be final. On brief in this
    Court, Ms. Oglesby advises that she appealed the circuit court’s exclusion of Dr. Caplan’s
    testimony and grant of summary judgment only as to the negligence claim.
    5
    At the November 8, 2022 general election, the voters of Maryland ratified a
    constitutional amendment changing the name of the Court of Special Appeals of Maryland
    to the Appellate Court of Maryland. The name change took effect on December 14, 2022.
    -3-
    determining that Dr. Caplan’s testimony that Ms. Oglesby’s exposure to lead at the
    property was a significant contributing factor to her injuries was inadmissible.
    We remand the case, however, for further proceedings consistent with this Court’s
    holding in Rochkind v. Stevenson, 
    471 Md. 1
    , 
    236 A.3d 630
     (2020), for a determination as
    to whether the methodology Dr. Caplan employed under the Canfield and Lanphear studies
    reliably supports the conclusion that Ms. Oglesby’s exposure to lead resulted in a loss of
    approximately 3 to 4 IQ points, should Ms. Oglesby seek to introduce such testimony at
    trial.
    Having concluded that the circuit court abused its discretion in granting the motion
    to preclude, we hold that the circuit court erred in granting summary judgment. The circuit
    court’s ruling—that Ms. Oglesby was unable to prove negligence without Dr. Caplan’s
    testimony as to causation—was not warranted. Ms. Oglesby presented sufficient evidence
    that the property was a reasonably probable source of her exposure to lead and that the
    exposure was a significant contributing factor to her injuries, other than IQ loss, to establish
    a prima facie case of negligence. Accordingly, we reverse the judgment of the Appellate
    Court and remand the case to that Court with instruction to remand the case to the circuit
    court for trial or further proceedings under Rochkind, 
    471 Md. 1
    , 
    236 A.3d 630
    , with
    respect to Dr. Caplan’s opinion as to IQ loss, should Ms. Oglesby seek to introduce such
    evidence at trial.
    BACKGROUND
    Residential History
    At the outset, we point out that all of the material facts concerning Ms. Oglesby’s
    -4-
    alleged exposure to lead-based paint—such as whether there was lead present at the
    property at the time Ms. Oglesby lived there; whether Ms. Oglesby came into contact with
    lead at the property through peeling or chipping paint; and whether she suffered injury due
    to any such exposure—were disputed in the circuit court.6
    Ms. Oglesby alleges that she suffered lead-based paint poisoning while residing at
    2000 East North Avenue in Baltimore City, Apartment 202, for approximately three years
    when she was a child.7 Ms. Oglesby was born on April 12, 1998. For the first eight months
    of her life, Ms. Oglesby lived with her mother, Casey Powell, at her grandmother’s (Ms.
    Powell’s mother’s) house on East Jefferson Street. At deposition, Ms. Powell testified that
    the house on East Jefferson Street was in good condition and that she did not recall any
    issue with peeling or flaking paint.8
    6
    The information concerning Ms. Oglesby’s residential history set forth in the
    Background section of the opinion is derived from Ms. Oglesby’s complaint, deposition
    testimony of witnesses, Respondents’ motion to preclude expert testimony and motion for
    and memorandum in support of summary judgment, Ms. Oglesby’s response and
    memorandum in opposition to the motions, and exhibits attached to the motions and
    memoranda.
    7
    In the complaint, Ms. Oglesby alleged that she was exposed to lead in the common
    areas of the property as well as in the apartment, and referred to the apartment as “the
    leased premises.”
    8
    According to Respondents, shortly after Ms. Oglesby’s birth, Ms. Powell moved
    out of the East Jefferson Street address on her own and lived at a different address—706
    Milton Avenue. Respondents also allege that in December 1998, when she applied to live
    at 2000 East North Avenue, Ms. Powell listed 338 Mason Court as her prior residence in
    an application to transfer her Baltimore Gas & Electric service to the property.
    Respondents contend that Dr. Caplan failed to rule out the East Jefferson Street,
    Milton Avenue, and Mason Court locations as contributing to Ms. Oglesby’s first BLL and
    that multiple sources of exposure to lead may have contributed to her alleged injuries. As
    we explain below, these contentions, which, in part, constitute factual disputes concerning
    sources of Ms. Oglesby’s exposure to lead, do not render Dr. Caplan’s opinion as to the
    source and cause of Ms. Oglesby’s injuries inadmissible.
    -5-
    On December 18, 1998, when Ms. Oglesby was eight months old, she and Ms.
    Powell moved into 2000 East North Avenue, Apartment 202.9 Respondents owned and
    managed the apartment building. At deposition, Ms. Powell testified that the apartment
    was in poor condition when she moved in, and she did not do a walk-through with the
    landlord before signing the lease and receiving a key.10 According to Ms. Powell, when
    she moved in, she noticed peeling or chipping paint “everywhere” in the building,
    “[t]hroughout the hallways[, t]he stairwells[, s]ome outdoors[,]” and “[s]ome of [the]
    apartments ha[d] peeling paint on it.” Ms. Powell testified that the front door of the
    building and the vestibule inside the back door of the building also contained peeling
    paint.11 Ms. Powell testified that she did not see her children touch or put any peeling paint
    9
    Ms. Oglesby also had two brothers who lived in the apartment. Ms. Oglesby’s
    brother Keshar was born in May 1999, and her brother Quran was born in December 2000.
    Ms. Oglesby’s brothers lived in the apartment until the family moved in January or
    February 2002.
    10
    According to a Crowninshield Management Corporation “Move-In Move-Out
    Inspection” form, which is Exhibit 5 to the memorandum in support of Respondents’
    motion for summary judgment, a move-in inspection of the apartment occurred on
    December 18, 1998. No deficiencies were noted on the form, and the form was signed by
    a representative of Crowninshield Management Corporation and purportedly by Ms.
    Powell.
    11
    Ms. Oglesby attached as exhibits to the memorandum in support of her response
    to the motion for summary judgment and motion to preclude excerpts of depositions taken
    in other lead-based paint cases involving Baltimore Schools Associates and 2000 East
    North Avenue.
    At a deposition taken in Ikem Ravenell v. Balt. Schs. Assocs., et al., No. 24-C-16-
    007111 (Cir. Ct. Balt. City), Tasha Transou, who lived in Apartment 103 in the building,
    testified that the building had paint chipping on all of the doors, “chipping paint all falling
    in the hallway[,]” chipping, flaking paint on the metal railing along the steps leading up to
    the building, and that “the paint was chipping and peeling all the way through the hallway
    when you walked through to get to [her] apartment[.]” Ms. Transou testified that she was
    -6-
    in their mouths, but indicated that Ms. Oglesby may have picked up peeling paint in a
    hallway, where she played.
    According to Ms. Powell, although the apartment was in poor condition when she
    moved in, she did not recall any issue initially with peeling or chipping paint inside the
    apartment. Within six or seven months, though, Ms. Powell noticed peeling paint on the
    walls and windowsills and in the bathroom of the apartment, and that the paint in a closet
    was peeling from moisture. Ms. Powell testified that, approximately a year after she moved
    into the apartment, management repainted the building’s common areas and the doors of
    the apartments, but the “paint that they put over the peeling paint started peeling off again.”
    Ms. Powell testified that, at the time of the repainting, she asked management to repaint
    her window, the closet, and other locations inside the apartment, but management repainted
    only one window inside the apartment.
    A Crowninshield Management Corporation annual unit inspection report, in an
    exhibit attached to Ms. Oglesby’s opposition to the motions for summary judgment and to
    preclude, indicates that, on October 7, 2001, a representative of the company conducted an
    annual inspection of the apartment and noted that components in every room were
    unacceptable and needed rehabilitation, including doors, walls, floors, windows, and the
    the last person who lived in Apartment 103 before the building was shut down due to the
    poor living conditions.
    At a deposition taken in connection with another case brought against Respondents,
    Jua’Drek Addison v. Balt. Schs. Assocs., LLP, et al., No. 24-C-17-004504 (Cir. Ct. Balt.
    City), Juanita Addison testified that she would bring her son with her every day to visit her
    sister, who lived in the building, and that the building contained peeling paint.
    -7-
    bathroom ceiling.12 Ms. Powell testified that in or around January or February 2002, when
    Ms. Oglesby was three years and nine or ten months old, after having stayed briefly with
    her brother in December 2001, the family moved out of the apartment.13 Ms. Powell
    testified that the apartment building was being closed down and they were told to relocate.14
    It is undisputed that the building was not well maintained and that in early 2002,
    Respondents closed the building rather than make necessary repairs.15
    12
    Annual unit inspection reports dated October 19, 1999, and October 27, 2000,
    which were Exhibits 8 and 9, respectively, to the memorandum in support of Respondents’
    motion for summary judgment, indicated that the components in the apartment were in
    acceptable condition on those dates.
    13
    Ms. Powell testified that, in December 2001, after a robbery occurred at the
    apartment, she and her children, including Ms. Oglesby, stayed with her brother, who lived
    in the 2800 block of Lafayette, for “a couple weeks[.]” Ms. Powell testified that she did
    not know of any issues with peeling paint at her brother’s house while she stayed with him.
    14
    Ms. Powell also testified that while she and Ms. Oglesby resided at the property,
    she and her siblings did “weekend swaps[,]” in which the adults took turns caring for each
    other’s children. During the weekend swaps, Ms. Oglesby would spend time at her uncle’s
    (Ms. Powell’s brother’s) house once or twice a month in the 2800 block of Lafayette, and
    she would also spend time each month at another uncle’s house and her aunt’s house.
    Respondents contend that the Lafayette residence was a source of exposure to lead for Ms.
    Oglesby, as her uncle brought a lead-based paint action, alleging that his two sons were
    exposed to lead at the residence. As explained below, this contention, which, in part,
    constitutes a factual dispute, does not render Dr. Caplan’s opinion as to the source and
    cause of Ms. Oglesby’s injuries inadmissible.
    15
    An article from the November 24, 2001 edition of The Baltimore Sun, Vision for
    dwellings becomes another city housing nightmare by Eric Siegel, was attached as an
    exhibit to Ms. Oglesby’s memorandum in support of her opposition to the motion for
    summary judgment and motion to preclude. According to the article, in a letter to City
    housing officials in June 2001, the president of Crowninshield Management Corporation
    stated that the six Schoolhouse Apartment buildings were “extremely difficult to maintain”
    and that Crowninshield was unable to manage the building at 2000 East North Avenue to
    “anyone’s minimum standards.” The article stated that, on November 7, 2001, the United
    States Department of Housing and Urban Development (“HUD”) notified the City’s
    Housing Authority that it had violated its obligation to keep the buildings in safe and
    sanitary condition, that all six buildings were in unacceptable condition, and that the
    -8-
    Ms. Powell testified that, beginning in January or February 2002, she and Ms.
    Oglesby resided at 1713 Lemmon Street. Ms. Powell described the Lemmon Street address
    as a three-story row house that was “newly renovated[,]” where “[e]verything was fresh[,]”
    with “[n]othing peeling[.]” Ms. Powell testified that, sometime in the winter of 2003-2004,
    the family moved from Lemmon Street to a house on Mosher Street. According to Ms.
    Powell, the Mosher Street house had peeling paint in the basement, where she did not allow
    her children to go, in a pantry in the kitchen, and “a little bit” in a back bedroom where
    there had been a roof leak and water damage. Ms. Powell also recalled peeling paint and
    dust on the wooden floors of the Mosher Street house. In 2005, the family moved from the
    Mosher Street house, in part because the landlord would not make repairs to the property.
    Ms. Powell testified that, afterward, she and Ms. Oglesby lived at a property on Elmora
    Street followed by a property on North Ellwood.16
    Ms. Oglesby’s BLLs
    Ms. Oglesby’s BLLs were tested on three occasions between 1999 and 2004. A
    sample of Ms. Oglesby’s blood collected on April 19, 1999, while Ms. Oglesby resided in
    the apartment, showed that Ms. Oglesby had a BLL of 2 micrograms per deciliter
    building at 2000 East North Avenue, where at least two-thirds of 37 units were vacant, was
    in the worst shape. According to the article, HUD ordered the Housing Authority to create
    a plan to restore the properties within 30 days and, 5 days later, Crowninshield issued
    eviction notices and informed City officials that it was closing all six buildings.
    16
    On brief, Respondents contend that Ms. Powell “believed” that Ms. Oglesby had
    an elevated BLL while living on North Ellwood and that Ms. Oglesby “believes” her
    physician determined that she had an elevated BLL in high school. Respondents assert
    that, in forming his opinion, Dr. Caplan did not take into account the two subsequent BLLs.
    Respondents do not identify, however, any BLL test results other than the three described
    below, which Dr. Caplan relied on.
    -9-
    (“μg/dL”).17 A sample of Ms. Oglesby’s blood collected on March 27, 2002, shortly after
    she moved out of the apartment, showed that Ms. Oglesby had a BLL of 5.5 µg/dL. Finally,
    a sample of Ms. Oglesby’s blood collected on August 20, 2004 showed that Ms. Oglesby
    had a BLL of 4 µg/dL.
    The Property: 2000 East North Avenue
    The building was constructed in 1890 and first served as a schoolhouse in Baltimore
    City. As of March 1979, lease and development agreements between the City of Baltimore
    and Baltimore Schools Associates provided for Baltimore Schools Associates to convert
    six vacant school buildings, including the one at 2000 East North Avenue, into apartment
    buildings and to maintain the properties as rental apartments for low-income tenants
    through 2030. The six buildings became known as the Schoolhouse Apartments.18
    According to Ms. Oglesby’s response to Respondents’ motions, because the
    17
    BLLs “are measured in micrograms per deciliter (μg/dL) of blood” and, “[a]s of
    2012, the Centers for Disease Control and Prevention consider[ed BLLs] greater than 5
    μg/dL to be elevated.” Levitas v. Christian, 
    454 Md. 233
    , 238 n.3, 
    164 A.3d 228
    , 231 n.3
    (2017) (citations omitted). As of 2021, the Centers for Disease Control and Prevention
    “use[d] a blood lead reference value (BLRV) of 3.5 micrograms per deciliter (μg/dL) to
    identify children with [BLLs] that are higher than most children’s levels.” Centers for
    Disease Control and Prevention, Blood Lead Reference Value (last reviewed Dec. 2, 2022),
    https://www.cdc.gov/nceh/lead/data/blood-lead-reference-value.htm       [https://perma.cc/
    3DXX-YTYR]. See also Centers for Disease Control and Prevention, CDC updates blood
    lead reference value to 3.5 μg/dL (last reviewed Dec. 16, 2022)
    https://www.cdc.gov/nceh/lead/news/cdc-updates-blood-lead-reference-value.html
    [https://perma.cc/X5B5-94RV] (“On October 28, 2021, CDC updated the blood lead
    reference value (BLRV) from 5.0 μg/dL to 3.5 μg/dL.”).
    18
    The project was subsidized through a $4.1 million loan from the City, and rents
    were to be paid by the United States Department of Housing and Urban Development
    through the City’s Housing Authority under the Section 8 program.
    - 10 -
    building at 2000 East North Avenue was built before 1950 and not certified as lead-free,
    Respondents registered the building with the Maryland Department of the Environment’s
    Lead Poisoning Prevention Program in February 1995, which demonstrated that the
    building was not, in fact, lead-free. Ms. Oglesby pointed out that the building received
    lead-based paint risk reduction certificates, rather than lead-free certificates, from the
    Maryland Department of the Environment on December 4, 1996, June 16, 1998, and
    January 28, 1999.
    Records indicate the building at 2000 East North Avenue has been inspected or
    tested for lead by three different entities on three separate occasions, once before Ms.
    Oglesby’s residency and twice afterward. In 1989, the Baltimore City Health Department
    issued an “Emergency Violation Notice and Order to Remove Lead Nuisance” for
    Apartment G-2 in the building after it had been determined by the Department that a child
    who frequented the apartment had “an abnormal” BLL and an inspection of the unit showed
    that “it contain[ed] lead[-]based paint.” The Department ordered the removal of lead-based
    paint from the building’s front exterior doors, front vestibule door and frame, rear exterior
    doorframes, and west exit doors and drainpipes.
    On April 13, 2011, Arc Environmental, Inc., a company providing inspection and
    consulting services, conducted a lead-based paint inspection of Apartment 203 and other
    areas of the building. On April 20, 2011, Arc Environmental issued a “Lead-based Paint
    Survey Report,” concluding that lead-based paint above the Maryland standard was
    detected on window jambs in the living room and two bedrooms in Apartment 203.
    Apartment 203 was the only apartment tested by Arc Environmental. Lead-based paint
    - 11 -
    above the Maryland standard was also detected, however, on the first- to second-floor rear
    stairs baluster and newel post, the first-floor rear hallway wall, the second-floor hallway
    window jamb, and the first-to-second floor front stairs window casing.
    On April 17 and 18, 2012, Green Street Environmental, a Maryland-licensed lead
    inspection contractor, conducted a lead-specific X-ray fluorescence analysis of painted
    building components at 2000 East North Avenue. On April 20, 2012, Green Street
    Environmental issued a report, indicating that 84 areas throughout the building contained
    lead-based paint. In floor plans attached to the report, apartments and other areas such as
    stairways and hallways are identified in numerical order, starting with “1,” on each floor
    of the building, and are called “rooms” in the report. In other words, in the report, former
    apartments are not identified by the numbers that they had when occupied by residents.19
    On the second floor, there are 12 rooms identified by numbers 1 through 12. Two
    of the rooms are stairways: room 1 and 7. Room 2 is a hallway. Room 8 is a large area
    bearing a notation that part of it is destroyed and inaccessible. The remaining rooms on
    the second floor are rooms 3, 4, 5, 6, 9, 10, 11, and 12. Green Street Environmental
    provided the following floor plan for the second floor of the building:
    19
    In a Rental Property Registration form for the Maryland Department of the
    Environment’s Lead Poisoning Prevention Program completed in February 1995, the
    apartment units in 2000 East North Avenue were identified, at that time, by the following
    numbers: G1 through G5, 101 through 114, 201 through 214, and 301 through 304.
    According to the information on the form, there were apartments on the ground floor, first
    floor, second floor, and third floor of the building.
    - 12 -
    According to the report, rooms that had been apartments on both the first and second
    floors of the building contained lead-based paint on windowsills, window casings, and
    window troughs in living rooms and bedrooms, on living room, bedroom, and bathroom
    - 13 -
    walls and wainscots, and on kitchen and apartment storage room walls. With respect to
    the second floor, the report states that locations in rooms 3, 4, 5, 6, 7, 9, and 11 tested
    positive for lead-based paint. The only rooms on the second floor that did not test positive
    for lead-based paint were rooms 1 (a stairway), 2 (a hallway), 8 (a large area marked partly
    destroyed and inaccessible), and rooms 10 and 12 (potentially former apartments). In the
    report, Green Street Environmental stated that areas of the building that were not accessible
    for inspection “likely contain[ed] components that would test positive for Lead[-]Based
    Paint.”
    Dr. Caplan’s Report and Deposition
    In a report dated December 26, 2019, Dr. Caplan concluded that Ms. Oglesby’s
    “likely exposure to lead at 2000 E. North Ave is a significant contributing factor to her lead
    intoxication” and to her impairments or “difficulties” described in the report. Dr. Caplan
    concluded that Ms. Oglesby “was exposed to environmental lead and had academic and
    behavioral problems in school, attentional issues, and symptoms of depression.” Dr.
    Caplan explained that Dr. Hawkins-Heitt performed a neuropsychological evaluation of
    Ms. Oglesby on January 28, 2019 and determined that her areas of impairment included
    “visual and working memory, visual attention speed, visual motor integration and copying
    skills, encoding and recognition of verbal information, recall of complex visual
    information, and categorical verbal fluency,” and that she had a full scale IQ score of 80,
    which is “at the lowest end of the low average range.” Dr. Caplan reported that, “according
    to the United States Environmental Protection Agency, the American Academy of
    Pediatrics, the Maryland Department of the Environment, and the World Health
    - 14 -
    Organization[,]” “[l]ead is a causal or likely causal factor” for academic and behavioral
    problems, attentional issues, and symptoms of depression.
    Dr. Caplan explained that Mr. Lieberman performed an employability assessment
    of Ms. Oglesby on September 13, 2019, and determined she performed low or below
    average in areas related to word knowledge, language arts, and verbal reasoning, and that
    she would be “classified as a Cognitively Disabled female by the American Community
    Survey of the U.S. Census Bureau.” In addition to his opinion concerning her other
    impairments, Dr. Caplan concluded that, “[e]xtrapolating from the data of Canfield and
    Lanphear, an IQ deficit of about 3 to 4 IQ points can be attributed to [Ms. Oglesby’s] lead
    exposure.”
    In the report, prior to setting forth his opinion about Ms. Oglesby’s exposure to lead
    at the property being a significant contributing factor to her alleged injuries, Dr. Caplan
    discussed information concerning Ms. Oglesby’s residential history and the condition of
    2000 East North Avenue. Dr. Caplan reported that Ms. Oglesby lived at 2000 East North
    Avenue from December 1998 until late 2001 or early 2002. Dr. Caplan noted that the
    building at 2000 East North Avenue was built before 1950 and had “multiple inspections
    indicating the presence of lead based paint.” Dr. Caplan reported that on October 5, 1989,
    the Baltimore City Health Department issued an emergency lead paint violation notice; on
    April 13, 2011, an inspection performed by Arc Environmental found multiple areas
    containing lead; and on April 17 and 18, 2012, and again from June 30 to July 3, 2014,
    Green Street Environmental analyzed the building and found multiple areas containing
    lead-based paint.
    - 15 -
    Based on his review of the records provided to him, Dr. Caplan concluded that lead
    paint “was accessible” to Ms. Oglesby “during her tenancy” at the building. Dr. Caplan
    explained that Ms. Powell “described the apartment as being in poor condition with peeling
    and chipping paint throughout the hallways and stairwells as well as from the doors” and
    that paint in the apartment “began to peel about six months after she moved in.” Dr. Caplan
    noted that some repainting was performed in the building and on one window in Ms.
    Oglesby’s apartment; however, chipping and peeling of the paint occurred after the
    repainting. Dr. Caplan observed that the October 7, 2001 annual inspection for the
    apartment “indicated multiple rooms needing rehabilitation.” Dr. Caplan also noted that
    “multiple other children who lived at 2000 E. North Ave from the late 1980’s to the early
    2000’s suffered from lead intoxication.”
    As to other properties, Dr. Caplan stated that, in late 2001 or 2002, Ms. Oglesby
    moved to the Lafayette location for a few weeks before moving to Lemmon Street, and that
    both of those properties were reported to have “had no peeling paint.” Dr. Caplan indicated
    that Ms. Oglesby had “no significant visitations to other properties” during the time that
    she resided at 2000 East North Avenue.
    At a deposition taken on February 25, 2020, Dr. Caplan verified that, prior to
    completing his report, he reviewed 24 items pertaining to the case, including the
    depositions of Ms. Powell and Ms. Oglesby,20 and that he reviewed an additional 5 items
    20
    The items that Dr. Caplan reviewed before completing his report included the
    following documents pertaining to Ms. Oglesby: Maryland Department of the Environment
    records; Maryland Department of Health and Mental Hygiene (now the Maryland
    - 16 -
    before deposition.21 Dr. Caplan testified that his opinion was that Ms. Oglesby was
    exposed to lead at 2000 East North Avenue, that she had suffered “sequelae from all the
    exposure to lead that she’s had[,]” and that she had incurred an IQ deficit of approximately
    3 to 4 points, i.e., that Ms. Oglesby’s IQ score would have been 83 or 84.22
    Department of Health) records; University of Maryland Medical Center records; Total
    Health Care medical records totaling 30 pages; Dr. Hawkins-Heitt’s report; a report from
    Mr. Lieberman concerning Ms. Oglesby’s vocational capabilities, limitations, and future
    earning potential; and a report from Michael A. Conte, Ph.D., an expert in the areas of
    economics and forensic economics designated by Ms. Oglesby. In addition, Dr. Caplan
    reviewed, among other things: Ms. Powell’s tenant file totaling 114 pages; the “Property
    Card” for 2000 East North Avenue; Green Street Environmental’s report; Arc
    Environmental’s report; Maryland Department of the Environment records concerning
    2000 East North Avenue totaling 21 pages; records of the Maryland Department of the
    Environment’s Lead Poisoning Prevention Program for 2000 East North Avenue totaling
    43 pages; Maryland Department of the Environment inspection certificates for Unit 208 of
    2000 East North Avenue totaling 25 pages; and Maryland Department of the Environment
    records concerning Ikem Ravenell and 2000 East North Avenue totaling 28 pages.
    21
    The 5 additional items reviewed by Dr. Caplan prior to deposition were: a
    psychological evaluation report from Neil Hoffman, Ph.D.; Dr. Hoffman’s deposition and
    exhibits; Mr. Lieberman’s deposition and exhibits; Dr. Conte’s deposition; and his own
    report on Ms. Oglesby.
    22
    The deposition transcript shows that the following exchange occurred between
    Respondents’ counsel and Dr. Caplan as to Ms. Oglesby’s IQ loss:
    [RESPONDENTS’ COUNSEL:] Going on to the next paragraph you
    referenced the testing of [Ms. Oglesby] with an IQ score of 80 and you agree
    that an IQ score of 80 is in the low average range?
    [DR. CAPLAN:] It’s the lowest number in the low average range, yes.
    [RESPONDENTS’ COUNSEL:] Am I correct that the range for low average
    is 80 to 89?
    [DR. CAPLAN:] Correct.
    [RESPONDENTS’ COUNSEL:] So it is your opinion that after the alleged
    lead exposure her IQ would have been 83 or 84?
    - 17 -
    Dr. Caplan testified that he reviewed “data from Lanphear in his pooled analysis as
    well as Canfield from a 2003 article” and that he “extrapolated from the data that they put
    forth” and determined a result. Although Dr. Caplan did not specifically testify to this, his
    calculations demonstrate that he determined that the Lanphear and Canfield studies indicate
    that every 1 μg/dL in a BLL leads to a loss of 0.62 or 0.74 IQ points, respectively. Dr.
    Caplan testified that he calculated, based on the average of Ms. Oglesby’s BLLs, 3.8
    µg/dL,23 that Ms. Oglesby would have lost approximately 2.4 (3.8 times 0.62) IQ points
    according to the Lanphear study or 2.8 (3.8 times 0.74) IQ points according to the Canfield
    study.
    Dr. Caplan calculated that, based on Ms. Oglesby’s highest or peak BLL, 5.5 µg/dL,
    she would have lost approximately 3.4 (5.5 times 0.62) or 4.1 (5.5 times 0.74) IQ points
    according to the Lanphear and Canfield studies, respectively. In sum, Dr. Caplan used Ms.
    Oglesby’s average and peak BLLs, and concluded that, under the Lanphear study,
    multiplied by a factor of 0.62, her loss of IQ points was 2.4 to 3.4 points, and that, under
    the Canfield study, multiplied by a factor of 0.74, her loss of IQ points was 2.8 to 4.1 points.
    Dr. Caplan rounded the numbers to 2 to 3 points and 3 to 4 points, respectively.
    Dr. Caplan testified that Ms. Oglesby’s BLL of 5.5 μg/dL was pertinent to the East
    [DR. CAPLAN:] Approximately.
    It is clear that, in this exchange, Dr. Caplan confirmed his opinion concerning an IQ loss
    of 3 to 4 points.
    23
    The average of the results of Ms. Oglesby’s three BLL tests (i.e., 2, 5.5, and 4
    µg/dL) was approximately 3.8 µg/dL.
    - 18 -
    North Avenue address, as her blood was tested two to three months after she moved out of
    the building. Dr. Caplan explained that Ms. Oglesby moved “to a place that did not have
    peeling and chipping paint” and that it was “very likely” that the East North Avenue
    address was responsible for her BLL of 5.5 μg/dL. Dr. Caplan testified that Ms. Oglesby’s
    BLL “might have been even higher two months earlier and then started to fall during those
    two to three months that she left.” When asked about Ms. Oglesby’s IQ loss, Dr. Caplan
    testified that, even with a three-point IQ loss, going from an IQ of 83 to 80, Ms. Oglesby’s
    “neuro executive functioning has been affected” and she would be “functioning at a little
    bit lower level[.]”
    The Circuit Court’s Ruling
    On April 29, 2020, the circuit court conducted a hearing on Respondents’ motions.
    In a single hearing, the circuit court heard argument on motions to preclude expert opinions
    and testimony and motions for summary judgment in Ms. Oglesby’s case and a second
    unrelated case, and a motion for summary judgment in a third unrelated case. In all three
    cases, plaintiffs who were represented by Ms. Oglesby’s counsel had sued Respondents,
    claiming injuries due to lead-based paint exposure at different locations, 2000 East North
    Avenue, 249 Aisquith Street, and 511 South Bond Street. See Tybria Cheley v. Balt. Schs.
    Assocs., et al., No. 24-C-18-000313 (Cir. Ct. Balt. City); Dwanshayne Johnson v. Balt.
    Schs. Assocs., et al., No. 24-C-18-001928 (Cir. Ct. Balt. City). At the hearing, the circuit
    court granted the motions to preclude Dr. Caplan’s opinions and testimony in Ms.
    Oglesby’s case and in Johnson.
    In granting the motions, the circuit court ruled on Ms. Oglesby’s case and the
    - 19 -
    Johnson case together. The circuit court began by stating: “As it relates to the two Motions
    to Preclude the Opinions and Testimony of Dr. Caplan, the Court has had an opportunity
    to review the pleadings.” The circuit court observed that Levitas v. Christian, 
    454 Md. 233
    , 
    164 A.3d 228
     (2017) shows that “a qualified expert can rely on other research and can
    rely on another doctor’s report[.]” The circuit court stated that Levitas was different,
    though, ruling:
    However, the difference here, in Levitas there was -- the issue in
    Levitas was the expert’s use of -- well, a couple things. One is using --
    relying on a report of another doctor, and also relying on a particular type of
    research, which I think was Lanphear in that case, and there had been some
    question, I think about it.
    But the bottom line was the Court found a qualified expert can rely on
    other research and can rely on another doctor’s report, and things like that.
    That’s different from what we have in this case.
    What we have in this case is there -- it’s the opposite of relying on the
    research that was cited by the expert in this particular case. So at the outset
    let me say Rule 5-702 allows expert testimony to be admitted. There are
    three factors that have to be satisfied, the third and most relevant here is
    whether there is a sufficient factual basis to support the expert testimony.
    For the most part, the case law will say that once you have a qualified
    expert their -- the factual basis generally will go before a jury because it is
    up to a jury to weigh the credibility of the expert. And that is generally based
    on what is it -- whatever it is that they use to reach their conclusions in their
    opinions. It’s proper for cross-examination and they jury can decide, “Well,
    you know, he looked today, [sic] but he didn’t look at B, this doesn’t, you
    know.” The jury gets the opportunity then to evaluate that credibility.
    The problem that we have in this case is that there are a couple of
    things, particularly as it relates to a factual basis. Again, some of what is
    being argued by Defendants could be for the jury. But then there are other
    things, particularly like in the Johnson case, I mean, it’s undisputed that he -
    - some of what he relied on was just incorrect. The facts -- they -- it was just
    incorrect information that he relied on.
    And also, in both of the cases he does not use all of the available blood
    level -- blood lead level information in formulating his IQ loss opinions. And
    then notwithstanding that, he uses methodology that has not been shown to
    be accepted. As a matter of fact, it’s directly and expressly contradictory to
    that which he actually identifies as generally accepted research in the field.
    - 20 -
    And the problem that this Court has, he offers no explanation as to why he
    did it. He offered no support for using that -- those calculations in that way.
    And also again, there’s nothing to support that -- the way that he chose
    to interpret, I guess if you will, for the methodology that he chose in this case
    is acceptable, and also not contrary to that, which again, he cited.
    So that combined with the fact that there are some issues as it relates
    to the facts that he uses before he employs this methodology I think makes
    this a situation for which the Court can find that his opinion and his testimony
    is unreliable and shouldn’t be presented to a jury.
    And so for those reasons in each of the two cases, Ms. Oglesby and
    Mr. Johnson, the Court will grant the Motion to Preclude the Opinion
    Testimony of the Witness, Dr. Steven Caplan.
    Ms. Oglesby’s counsel immediately asked the circuit court for clarification of its
    ruling, pointing out that there were two separate cases. Counsel asked: “I just want to make
    sure that the record is clear when you stated that Dr. Caplan, you said that it’s undisputed
    that some of what he relies on is incorrect, and you said that specific to Johnson. That is
    not specific in the Oglesby case; is that correct?” The circuit court responded:
    So specific to Johnson when I said as it relates to incorrect
    information, based on what was presented by the defendant. Although, the
    Court also finds that -- I think the defense, just to be clear, has presented --
    what’s the word I’m trying to use? That there are issues, if you will, with the
    facts and the information that was gathered, and how it was gathered, and
    who he spoke to, and who he didn’t speak to.
    I think he’s present -- the defense has presented issues, and they are
    more typical and would more likely, as it relates to both case [sic]. And those
    would more likely be placed in front of a jury, which is very different from
    the completely incorrect information.
    But just to be clear, the basis of the Court’s ruling is not only when
    you combine those issues with the issue of the use of the methodology, the
    Court believes that together that makes his testimony and opinion inherently
    unreliable. And so it is a combination of factual issues and the expert’s
    methodology for both cases. But the incorrect information was presented to
    the Court, for what I believe is undisputed incorrect information, in the
    Johnson case. That’s the best I can give you on that.
    Later, during argument on the motion for summary judgment, Ms. Oglesby’s
    - 21 -
    counsel sought clarification as to whether Dr. Caplan would be permitted to render an
    opinion that “2000 East North Avenue was a substantial contributing factor in brin[g]ing
    about” Ms. Oglesby’s BLLs. The circuit court responded unequivocally that Dr. Caplan
    was “precluded from giving any opinion testimony, and that is more so because of the
    factual issues in both of the cases, which again, normally could be presented to a jury.”
    Specifically, the circuit court stated:
    So in this particular instance, the Court is ordering that the doctor be
    precluded from giving any opinion testimony, and that is more so because of
    the factual issues in both of the cases, which again, normally could be
    presented to a jury. And in this particular case, if we were to parse it out, we
    could, but I don’t believe that is appropriate. Or if there is a way to sort of
    parse out the two. And so this Court’s ruling is that the doctor give no
    opinion testimony based on the information gathered in these two cases.
    Ms. Oglesby’s counsel again sought clarification and the following occurred:
    THE COURT: Okay. Well, I don’t know how to be any more clear. In each
    of the two cases, exclusive of the other, the Court made findings that were a
    combination of problems with the facts, as well as problems with the
    methodology. And the Court, in either case, in both cases, and separately in
    each case, is finding that the issues with the facts are not going to be parsed
    out separately for him to give opinion testimony on other things.
    The Court has ruled that he’s not to give opinion testimony in either
    of the cases at all. That’s the best I can give you for the record. So with him
    not giving --
    [MS. OGLESBY’S COUNSEL]: Okay. Can -- can you please --
    THE COURT: -- opinion testimony --
    [MS. OGLESBY’S COUNSEL]: -- for the --
    THE COURT: -- I would ask that you proceed to your defense of the
    summary judgment please.
    [MS. OGLESBY’S COUNSEL]: Okay. There has been no -- for [Ms.]
    Oglesby there’s been no issue regarding any incorrect facts assumed by Dr.
    - 22 -
    Caplan. I think that was an issue only addressed by [Respondents’ counsel]
    in the [] Johnson matter, as far as the visitation period.
    However, just for the record, it is undisputed that [Ms.] Oglesby was
    at Apartment 202 of 2000 East North Avenue from December 1998 through
    December 2001. It is undisputed that lead was found inside 2000 East North
    Avenue subsequent to the ownership and management by Defendants of
    these properties. It’s undisputed that there’s a Baltimore City Health
    Department violation notice that found lead-based paint in 1989. That there
    was -- ARC Environmental found lead in the unit of 203. The lead was found
    throughout 2012 Green Street Environmental.
    At the conclusion of the hearing, the circuit court granted the motion for summary
    judgment as to the negligence claim in Ms. Oglesby’s case, concluding that Ms. Oglesby
    could not prove negligence without expert testimony on causation. On the same day, the
    circuit court issued orders, stating in both orders that the motions were granted “for the
    reasons stated on the record[.]”
    Ms. Oglesby filed a motion to alter or amend, or in the alternative for
    reconsideration of, the circuit court’s orders, which the circuit court denied. Ms. Oglesby
    filed a notice of appeal.
    Opinion of the Appellate Court of Maryland
    On August 9, 2022, the Appellate Court of Maryland affirmed the circuit court’s
    judgment, holding that the circuit court did not abuse its discretion in excluding Dr.
    Caplan’s testimony or err in granting summary judgment. See Jamaiya Oglesby v. Balt.
    Sch. Assocs., et al., No. 0130, Sept. Term, 2021, 
    2022 WL 3211044
    , at *8 (App. Ct. Md.
    Aug. 9, 2022). The Appellate Court explained that the case involved three areas of disputed
    facts: (1) whether there was any lead-based paint at 2000 East North Avenue at the relevant
    time, (2) whether Ms. Oglesby was exposed to any lead that may have been present at the
    - 23 -
    building through contact with deteriorated paint, and (3) whether Ms. Oglesby incurred
    any injury from exposure to lead while living at the building. See id. at *4-5. According
    to the Appellate Court, the circuit court found the disputed data to be inadequate to form
    the basis of Dr. Caplan’s opinions and, as a result, excluded his expert testimony. See id.
    at *5. The Appellate Court stated:
    Given the disputed nature of the evidence regarding the presence of lead in
    Apartment 202, the disputed nature of the evidence regarding Oglesby’s
    exposure to peeling paint, and the disputed nature of the evidence regarding
    any injury suffered as a result—combined with our deferential standard of
    review based on Levitas, Rochkind II, and Matthews . . . —however, we
    cannot say that the circuit court abused its broad discretion in finding that Dr.
    Caplan lacked an adequate supply of data.
    Oglesby, 
    2022 WL 3211044
    , at *5 (cleaned up). In reaching its conclusion, the Appellate
    Court stated: “[O]ur view is that these disputes made for a close question.” Id. at *5.
    With respect to Dr. Caplan’s opinion concerning Ms. Oglesby’s IQ loss, the
    Appellate Court explained that the Canfield and Lanphear studies
    have been frequently relied upon in previous lead paint cases, and Maryland
    courts have repeatedly held that a properly qualified expert witness can rely
    on the Lanphear Study methodology, as well as other accepted scientific
    research, as a factual basis for an opinion that a plaintiff’s elevated [BLLs]
    caused the loss of a specific number of IQ points.
    Id. at *6 (cleaned up). The Appellate Court stated that the circuit court’s “quarrel” with
    Dr. Caplan’s methodology was not that he relied on the studies, but that he had used them
    in a way that was not generally accepted and he had “offered no explanation for his
    methodology.” Id. (cleaned up). The Appellate Court concluded that, given the deferential
    abuse of discretion standard of review, the circuit court was within the bounds of its
    discretion in finding Dr. Caplan’s methodology for calculation of Ms. Oglesby’s IQ loss
    - 24 -
    unreliable. See id. at *7. The Appellate Court concluded that the circuit court did not err
    in granting summary judgment because, without Dr. Caplan’s testimony, Ms. Oglesby
    could not make a prima facie case of negligence, as she could not connect her exposure to
    lead at 2000 East North Avenue to her alleged impairments. See id. at *8.
    Petition for a Writ of Certiorari
    On September 6, 2022, Ms. Oglesby petitioned for a writ of certiorari, raising the
    following four issues:
    l.     Did the trial court abuse its discretion when it took factual issues away
    from the jury and resolved genuine disputes of material fact by ruling that
    Petitioner’s medical expert lacked an adequate supply of data to opine as to
    the source and source causation of Petitioner’s lead exposure, when there was
    substantial evidence for a jury to evaluate, including direct evidence of lead
    at the subject property, evidence of numerous areas of deteriorated paint,
    evidence that Petitioner lived in the subject property for three years and was
    exposed to and ingested lead resulting in her elevated [BLLs] and injury?
    2.     Did the trial court abuse its discretion when it took factual issues away
    from the jury and resolved genuine disputes of material fact by ruling that
    Petitioner’s medical expert’s opinion regarding Petitioner’s IQ loss was
    inadmissible, when Petitioner’s medical expert relied on studies that
    Maryland courts have repeatedly sanctioned?
    3.     Did the trial court err when it granted summary judgment after
    resolving genuine disputes of material fact related to the expert witness’
    source, source causation and IQ loss opinions and excluded Petitioner’s
    expert witness from testifying entirely when the jury could make the source
    determination and the expert had rendered numerous other opinions wherein
    jury could have found that Petitioner was injured from her exposure to and
    ingestion of lead?
    4.     Did the [Appellate] Court [] err in holding that the trial court did not
    abuse its discretion when it acted as the jury, inappropriately resolved
    genuine disputes of material facts and excluded the testimony of Petitioner’s
    expert witness in its entirety and that the trial court did not err in subsequently
    granting summary judgment?
    - 25 -
    On November 18, 2022, we granted the petition. See Oglesby v. Balt. Sch. Assocs., 
    482 Md. 142
    , 
    285 A.3d 848
     (2022).
    DISCUSSION
    Standard of Review
    This case involves a challenge to the admissibility of expert opinion under Maryland
    Rule 5-702(3) and Frye-Reed that originated before the issuance of Rochkind, 
    471 Md. 1
    ,
    
    236 A.3d 630
    . In Rochkind, 
    id. at 5
    , 236 A.3d at 633, this Court discontinued use of the
    “general acceptance” standard for admissibility of expert testimony set forth in Frye v.
    United States, 
    293 F. 1013
     (D.C. Cir. 1923) and Reed v. State, 
    283 Md. 374
    , 
    391 A.2d 364
    (1978) and adopted the standard set forth in Daubert v. Merrell Dow Pharms., Inc., 
    509 U.S. 579
     (1993) and its progeny.
    Before Rochkind, appellate courts reviewed a trial court’s decision as to the
    admissibility of expert testimony under two different standards of review, with a trial
    court’s determinations under Frye-Reed reviewed de novo and a trial court’s
    determinations under Maryland Rule 5-702 reviewed for abuse of discretion.            See
    Rochkind, 471 Md. at 37, 236 A.3d at 651. After Rochkind, id. at 37, 236 A.3d at 651, this
    Court reviews a trial court’s decision to admit or exclude expert opinion for an abuse of
    discretion. This Court has described an abuse of discretion as occurring “where no
    reasonable person would take the view adopted by the trial court[,]” Md. Bd. of Physicians
    v. Geier, 
    451 Md. 526
    , 544, 
    154 A.3d 1211
    , 1221 (2017) (cleaned up), or when “the
    decision under consideration [is] well removed from any center mark imagined by the
    - 26 -
    reviewing court and beyond the fringe of what that court deems minimally acceptable[,]”
    Wilson v. John Crane, Inc., 
    385 Md. 185
    , 199, 
    876 A.2d 1077
    , 1084 (2005) (cleaned up).
    “An appellate court reviews without deference a trial court’s grant of a motion for
    summary judgment, reviews the record in the light most favorable to the nonmoving party,
    and construes any reasonable inferences that may be drawn from the facts against the
    moving party.” State v. Rovin, 
    472 Md. 317
    , 341, 
    246 A.3d 1190
    , 1204 (2021) (cleaned
    up). Summary judgment is appropriate where “there is no genuine dispute as to any
    material fact and [] the [moving] party is entitled to judgment as a matter of law.” Md. R.
    2-501(a).
    Admission of Expert Testimony Generally
    Maryland Rule 5-702 provides that “[e]xpert testimony may be admitted, in the form
    of an opinion or otherwise, if the court determines that the testimony will assist the trier of
    fact to understand the evidence or to determine a fact in issue.”             In making that
    determination, the trial court must determine: “(1) whether the witness is qualified as an
    expert by knowledge, skill, experience, training, or education, (2) the appropriateness of
    the expert testimony on the particular subject, and (3) whether a sufficient factual basis
    exists to support the expert testimony.” Md. R. 5-702 (paragraph breaks omitted).
    The third factor, the existence of a sufficient factual basis, has been interpreted as
    encompassing two sub-factors—whether the expert had an adequate supply of data and
    whether the expert used a methodology that was reliable. See Sugarman v. Liles, 
    460 Md. 396
    , 415, 
    190 A.3d 344
    , 354 (2018); Rochkind, 471 Md. at 22, 236 A.3d at 642. Absent
    either sub-factor, an expert’s opinion is inadmissible. See Rochkind, 471 Md. at 22, 236
    - 27 -
    A.3d at 642. We have held that, to satisfy the requirement of a reliable methodology, “an
    expert opinion must provide a sound reasoning process for inducing its conclusion from
    the factual data and must have an adequate theory or rational explanation of how the factual
    data led to the expert’s conclusion.” Sugarman, 
    460 Md. at 415
    , 
    190 A.3d at 355
     (citation
    omitted).
    In addition, in determining whether an expert has a sufficient factual basis to offer
    an opinion, a court may consider whether there is too great an analytical gap between the
    data relied upon and the opinion proffered. See Rochkind v. Stevenson, 
    454 Md. 277
    , 289,
    
    164 A.3d 254
    , 261 (2017). The data or information upon which an expert relies must
    provide factual support for the opinions reached. See Sugarman, 
    460 Md. at 427
    , 
    190 A.3d at 362
     (“To bridge the analytical gap, an expert’s testimony must have a sufficient factual
    foundation. It is permissible for an expert to reasonably extrapolate from existing data
    provided that a sufficient factual basis for that opinion exists.” (Citations omitted)). But
    testimony may not be the ipse dixit conclusion of the expert. See 
    id. at 415
    , 
    190 A.3d at 355
     (“Conclusory or ipse dixit assertions are not helpful—an expert must be able to
    articulate a reliable methodology for how [the expert] reached [the] conclusion.” (Cleaned
    up)). Also, pursuant to Maryland Rule 5-703(a), “[a]n expert may base an opinion on facts
    or data in the case that the expert has been made aware of or personally observed.”
    I. The Factual Basis for Dr. Caplan’s Opinion
    Ms. Oglesby contends that, in excluding Dr. Caplan’s testimony, the circuit court
    abused its discretion by concluding that Dr. Caplan relied on incorrect information or that
    there were problems with the facts Dr. Caplan relied on, and in doing so resolved genuine
    - 28 -
    issues of disputed fact in favor of Respondents. Ms. Oglesby argues that the information
    that Dr. Caplan relied on was not incorrect, but rather was disputed and consisted of facts
    that, if believed by the jury, provided a sufficient factual basis for Dr. Caplan’s testimony.
    Respondents contend that the circuit court properly excluded Dr. Caplan’s
    testimony because, in their view, Dr. Caplan’s opinions were based on “limited”
    information provided by Ms. Oglesby’s counsel and, therefore, lacked a sufficient factual
    foundation. Respondents argue that Dr. Caplan failed to consider other potential sources
    of exposure to lead-based paint for Ms. Oglesby and merely assumed that Ms. Oglesby was
    exposed to lead at the property. Respondents maintain that the circuit court did not reject
    the accuracy of information that Dr. Caplan relied on, but rather concluded that Dr. Caplan
    did not have an adequate supply of data for his opinions.
    For two reasons, we agree with Ms. Oglesby that the circuit court abused its
    discretion in excluding Dr. Caplan’s testimony: (1) the record demonstrates that the circuit
    court impermissibly resolved issues of disputed fact in excluding Dr. Caplan’s opinion;
    and (2) Dr. Caplan’s opinion with respect to causation (other than as to Ms. Oglesby’s IQ
    loss) was supported by a sufficient factual basis.
    A. The Circuit Court Resolved Disputed Issues of Fact
    The circuit court abused its discretion in excluding Dr. Caplan’s testimony based on
    its assessment that there were factual issues in the case, which “normally could be
    presented to a jury[,]” but which in its view rendered the testimony inadmissible. In
    Frankel v. Deane, 
    480 Md. 682
    , 703-04, 
    281 A.3d 692
    , 705 (2022), we recently held that
    the trial court erred in precluding an expert’s testimony and concluded that the trial court
    - 29 -
    “improperly took sides in a credibility contest between” the defendants on one hand and
    the plaintiff on the other hand and “impermissibly gave” the defendants “the benefit of
    favorable inferences drawn from evidence susceptible to more than one interpretation.” In
    discussing whether a sufficient factual basis existed to support expert testimony under
    Maryland Rule 5-702(3), we explained that the factual basis for an expert’s opinion may
    “come from facts obtained from the expert’s first-hand knowledge, facts obtained from the
    testimony of others, and facts related to an expert through the use of hypothetical
    questions.” Id. at 700, 281 A.3d at 703 (cleaned up). We stated that “experts are permitted
    to express an opinion based upon facts assumed but not in evidence when the question is
    asked, if such facts are later proved in the case.” Id. at 700-01, 281 A.3d at 703 (cleaned
    up). Notably, “[t]his applies to disputed facts as well.” Id. at 701, 281 A.3d at 703. In so
    concluding, we explained that, in Kruszewski v. Holz, 
    265 Md. 434
    , 445, 
    290 A.2d 534
    ,
    540 (1972), we stated:
    [T]he proper way to submit a hypothetical question is to ask the witness to
    presume the truth of certain facts as if they were not the subject of dispute.
    These may still be contested in actuality but the inquiry is proper as long as
    there is evidentiary support for the facts which the expert is told to assume
    the veracity of and evaluate in rendering his opinion. Of course, any
    assumption made must be grounded on a fair summation of the material facts
    in evidence and those material facts must be sufficient in scope for the
    witness to formulate a rational opinion. In such a situation the jury is aware
    of the premise upon which the opinion is based and can determine whether
    that assumption was valid. If it is not, the opinion of the expert is
    disregarded.
    Frankel, 480 Md. at 701, 281 A.3d at 703-04.24
    24
    Ms. Oglesby contends that Parkway Neuroscience & Spine Inst., LLC v. Katz,
    - 30 -
    In this case, the record demonstrates that, in ruling that Dr. Caplan did not have an
    adequate factual basis for his opinion, the circuit court resolved disputed issues of fact.
    The circuit court expressly ruled that Dr. Caplan was “precluded from giving any opinion
    testimony, and that is more so because of the factual issues” that could normally go to a
    jury. In addition, the circuit court determined that information Dr. Caplan relied on was
    “incorrect[.]” We are aware that Respondents contend that the circuit court excluded Dr.
    Caplan’s opinions “not because it found [Respondents’] evidence more credible than [Ms.]
    Oglesby’s evidence,” but because it determined that the evidence upon which Dr. Caplan
    relied was “limited” or insufficient under Maryland Rule 5-702(3). We are not persuaded,
    however, by Respondents’ explanation of what the circuit court meant in ruling that Dr.
    Caplan relied on “incorrect information” and in finding that there were facts that could
    normally be submitted to the jury but that would not be in this case.
    The circuit court’s ruling can be viewed in three parts: its initial ruling and its
    responses to Ms. Oglesby’s counsel’s two requests for clarification. In initially ruling that
    Dr. Caplan relied on incorrect information and that there were issues with the facts, the
    circuit court did not explain what it meant, identify what the incorrect information was or
    factual issues were, or state whether the finding about incorrect information applied to both
    Abosch, Windesheim, Gershman & Freedman, P.A., 
    255 Md. App. 596
    , 
    283 A.3d 753
    (2022), cert. granted, 
    482 Md. 534
    , 
    288 A.3d 1231
     (2023) presents a similar issue involving
    a trial court having resolved issues of disputed fact in excluding expert testimony. This
    Court granted certiorari, and heard oral argument in Katz, Abosch, Windesheim,
    Gershman & Freedman, P.A., and Mark E. Rapson v. Parkway Neuroscience and Spine
    Inst., LLC, No. 30, Sept. Term, 2022, on May 4, 2023. Because Katz is pending, we will
    not comment on the case.
    - 31 -
    Ms. Oglesby’s case and Johnson’s, just Johnson’s, or just Ms. Oglesby’s case, or to only
    Dr. Caplan’s opinion concerning IQ loss or to all of his opinions. The most specific
    reference to what the circuit court deemed the factual issues to be was the court’s statement
    that, in both of the cases, Dr. Caplan had not used all available BLLs. Yet, in this case, Dr.
    Caplan’s report and deposition testimony show that he considered each of the three BLLs
    available in the record. The circuit court’s observation lends itself to the conclusion that,
    as to Ms. Oglesby’s case, the circuit court resolved what appeared to be a dispute of fact
    between the parties—whether Ms. Oglesby had other or higher BLL results later in her life
    that were not included in the record. Due to the nature of the circuit court’s initial ruling,
    Ms. Oglesby’s counsel immediately sought clarification and pointed out that there were
    two separate cases.
    When Ms. Oglesby’s counsel sought clarification as to whether the circuit court’s
    statement about incorrect information applied to the Johnson case and not Ms. Oglesby’s
    case, the circuit court compounded the confusion by responding, among other things, that
    the defense had presented issues “as it relates to both case[s]” and “those would more likely
    be placed in front of a jury, which is very different from the completely incorrect
    information.” The circuit court stated that, for both cases, “it is a combination of factual
    issues and the expert’s methodology[,]” “[b]ut the incorrect information was presented to
    the Court, for what I believe is undisputed incorrect information, in the Johnson case.”
    Conceivably, the circuit court’s response might somehow lend itself to the
    interpretation, as Respondents allege, that the circuit court intended to rule that Dr. Caplan
    relied on incorrect information only in the Johnson case and not in Ms. Oglesby’s case.
    - 32 -
    But, another interpretation of the circuit court’s ruling is that the court intended to rule that
    Dr. Caplan relied on incorrect information in both cases and on “undisputed” incorrect
    information in Johnson’s case. This was not, however, the last explanation given by the
    circuit court in response to a request for clarification.
    Later, during argument on the motion for summary judgment, when Ms. Oglesby’s
    counsel sought clarification as to whether Dr. Caplan would be permitted to render an
    opinion that 2000 East North Avenue was a substantial contributing factor to Ms.
    Oglesby’s BLLs, the circuit court responded that Dr. Caplan would be precluded from
    giving any opinion testimony whatsoever “because of the factual issues in both of the cases,
    which again, normally could be presented to a jury.” With this response, the court left no
    room to doubt that its ruling that there were issues with the facts that would normally go to
    the jury applied to both Ms. Oglesby’s case and Johnson’s. The circuit court stated that in
    Johnson and this case, “exclusive of the other,” the court had “made findings that were a
    combination of problems with the facts, as well as problems with the methodology.” The
    circuit court once more refused to identify or describe the factual problems that in its view
    precluded Dr. Caplan’s testimony. Instead, the circuit court stated that, “in either case, in
    both cases, and separately in each case,” it was “finding that the issues with the facts are
    not going to be parsed out separately for him to give opinion testimony on other things.”
    In the end, what can be gleaned from the circuit court’s ruling is that it determined
    that there were factual issues that could normally go to the jury, but would not in this case.
    Because the circuit court declined to explain or “parse” what the issues with the facts were,
    the court did not expressly identify the factual problems or how it resolved them. Implicit
    - 33 -
    in the circuit court’s decision to exclude Dr. Caplan’s testimony in its entirety, based on
    issues with the facts, instead of only his testimony concerning Ms. Oglesby’s IQ loss, is
    that the court resolved in Respondents’ favor factual disputes such as whether there was
    lead present at the property at the time that Ms. Oglesby lived there, whether Ms. Oglesby
    came into contact with lead at the property through peeling or chipping paint, and whether
    Ms. Oglesby was potentially exposed to lead at other locations and the condition of those
    properties.
    As our holding in Frankel, 480 Md. at 700-01, 281 A.3d at 703-04, demonstrates,
    where there is evidentiary support for the facts, an expert is permitted to express an opinion
    based on disputed facts, and questions may be asked of an expert in the form of a
    hypothetical in which an expert may presume the truth of certain facts as if they were not
    disputed. See also Fed. R. Evid. 702, advisory committee’s notes to 2000 amendment
    (“When facts are in dispute, experts sometimes reach different conclusions based on
    competing versions of the facts. The emphasis in the amendment on ‘sufficient facts or
    data’ is not intended to authorize a trial court to exclude an expert’s testimony on the
    ground that the court believes one version of the facts and not the other.”). In short, a trial
    court is not permitted to resolve disputes of material fact in determining whether a
    sufficient factual basis exists to support an expert’s opinion. Doing so is a clear abuse of
    discretion.
    B. Sufficient Factual Basis
    Although the facts were greatly disputed, Ms. Oglesby produced more than
    sufficient evidence that lead was present in the building at 2000 East North Avenue, that
    - 34 -
    she was exposed to lead-based paint at the property, and that the property was a source of
    her elevated BLLs and alleged injuries (other than her IQ loss) to provide a sufficient
    factual basis for Dr. Caplan’s opinions. Before addressing the factual basis for Dr.
    Caplan’s testimony, it is helpful to discuss principles of causation in lead-based paint cases.
    Causation in lead-based paint cases may be proven by showing that the defendant’s
    negligence was a “substantial factor” in causing the plaintiff’s injury. Ross v. Hous. Auth.
    of Balt. City, 
    430 Md. 648
    , 667, 
    63 A.3d 1
    , 12 (2013) (cleaned up). We have held that a
    customary theory of specific causation25 in a lead-based paint case can be conceived of as
    a series of links: “(1) the link between the defendant’s property and the plaintiff’s exposure
    to lead; (2) the link between specific exposure to lead and the elevated [BLLs;] and (3) the
    link between those [BLLs] and the injuries allegedly suffered by the plaintiff.” Ross, 
    430 Md. at 668
    , 
    63 A.3d at 12
    . The first, second, and third links have sometimes been referred
    to as source, source causation, and medical causation, respectively. See, e.g., Rogers v.
    Home Equity USA, Inc., 
    453 Md. 251
    , 265, 
    160 A.3d 1207
    , 1215 (2017). With respect to
    the first link, the source of a plaintiff’s exposure to lead, it may be established either with
    or without expert testimony. See Ross, 
    430 Md. at 669
    , 
    63 A.3d at 13
     (“[T]he link between
    a defendant’s property and a plaintiff’s childhood exposure to lead paint and dust may be
    established through circumstantial evidence, even if expert testimony is not available.”).
    Indeed, even the second or third link may potentially be established without expert
    25
    “General causation addresses whether a particular substance can cause the kind of
    injury suffered by the plaintiff[,]” and “[s]pecific causation addresses whether the
    substance actually caused the plaintiff’s injury.” Sugarman, 
    460 Md. at 415-16
    , 
    190 A.3d at 355
     (citations omitted).
    - 35 -
    testimony. See, e.g., id. at 668, 
    63 A.3d at 13
     (“Expert opinion testimony could be helpful
    in establishing any of the links and might sometimes be essential in proving the second and
    third links.” (Footnote omitted)).
    To avoid summary judgment in a lead-based paint case, “a plaintiff must
    demonstrate only a reasonable probability as to each of these links”—a plaintiff is not
    required to irrefutably establish them. Rogers, 
    453 Md. at 265
    , 
    160 A.3d at 1215
     (citation
    omitted). Case law has recognized two ways in which a plaintiff in a lead-based paint case
    can establish the subject property as a reasonably probable source of the plaintiff’s lead
    exposure and resulting elevated BLLs. In Dow v. L & R Props., Inc., 
    144 Md. App. 67
    ,
    76-77, 
    796 A.2d 139
    , 144-45 (2002), the Appellate Court of Maryland held that a plaintiff
    can defeat a motion for summary judgment by presenting evidence that the subject property
    is the only possible source of the plaintiff’s lead exposure. With the second method, if
    there are allegedly multiple possible sources of lead exposure, a plaintiff can produce
    “enough evidence to establish that it is reasonably probable that the subject property
    contributed to [the plaintiff’s] lead poisoning.” Rogers, 
    453 Md. at 266
    , 
    160 A.3d at 1216
    .
    In such cases, a plaintiff can “rule in” the subject property as a reasonably probable source
    through either direct or circumstantial evidence. 
    Id. at 266
    , 
    160 A.3d at 1216
     (citation
    omitted).
    Source and Source Causation
    In this case, Ms. Oglesby sought to introduce Dr. Caplan’s expert testimony with
    respect to all three of the causation links. Even though, as Ms. Oglesby argues on brief,
    there was other evidence with respect to the property being a source of her exposure to
    - 36 -
    lead, Ms. Oglesby sought to use Dr. Caplan’s testimony to assist in establishing the first
    causal link, the link between the property and her exposure to lead, i.e., Ms. Oglesby sought
    to use Dr. Caplan’s testimony to assist in “ruling in” 2000 East North Avenue. In his report,
    Dr. Caplan concluded that Ms. Oglesby’s “likely exposure to lead at 2000 E. North Ave is
    a significant contributing factor to her lead intoxication and, therefore, to her” impairments.
    And, at deposition, Dr. Caplan testified that Ms. Oglesby’s second BLL of 5.5 µg/dL was
    related to her residency at the building. In reaching these conclusions, Dr. Caplan did not
    offer the opinion that 2000 East North Avenue was the sole source of Ms. Oglesby’s
    exposure to lead paint; rather, the substance of his report and testimony demonstrates that
    Dr. Caplan’s opinion was, as stated, that Ms. Oglesby’s likely exposure to lead at the
    building was a significant contributing factor to her injuries. In other words, Ms. Oglesby
    endeavored to use Dr. Caplan’s expert testimony and other evidence to establish a
    reasonable probability that exposure to lead-based paint at 2000 East North Avenue
    contributed to her alleged injuries—to rule in the property as a source of her exposure.
    In reaching the conclusion that Ms. Oglesby’s likely exposure to lead at 2000 East
    North Avenue was a significant contributing factor to her injuries, Dr. Caplan’s report and
    deposition testimony show that he relied on data, including: (1) independent test results
    showing the presence of lead in the building both before and after Ms. Oglesby’s residency;
    (2) reports of Crowninshield and others indicating that the building was in poor or bad
    condition during the time of Ms. Oglesby’s residency; (3) the testimony of Ms. Powell and
    others regarding chipping and peeling paint in the apartment and the building; (4) Ms.
    Oglesby’s BLLs; and (5) Dr. Hawkins-Heitt’s and Mr. Lieberman’s reports. Dr. Caplan
    - 37 -
    explained in his report:
    [Ms. Oglesby] lived at 2000 E. North Ave from December 1998 through late
    2001 or early 2002. This is a building built before 1950 with multiple
    inspections indicating the presence of lead based paint. The Baltimore City
    Health Department issued an Emergency Lead Paint Violation Notice on
    October 5, 1989. Arc Environmental performed an inspection on April 13,
    2011 and found multiple areas containing lead. Arc Environmental also
    performed inspections of multiple properties on the 2000 block of E. North
    Ave and found lead based paint in multiple areas of the seven properties.
    Green Street Environmental analyzed 2000 E. North Ave from April 17-18,
    2012 and again from June 30, 2014 to July 3, 2014. Multiple areas containing
    lead based paint were identified during both inspections. Furthermore,
    multiple other children who lived at 2000 E. North Ave from the late 1980’s
    to the early 2000’s suffered from lead intoxication. For [Ms. Oglesby] the
    lead paint was accessible during her tenancy. Her mother described the
    apartment as being in poor condition with peeling and chipping paint
    throughout the hallways and stairwells as well as from the doors. In her
    apartment the paint began to peel about six months after she moved in. Some
    repainting was performed in the hallways, stairways, and on one window
    inside her apartment. However, the chipping and peeling restarted after the
    repainting. Indeed the annual inspection dated 10/7/01 indicated multiple
    rooms needing rehabilitation. [Ms. Oglesby] moved in late 2001 or 2002 to
    2800 Lafayette for a few weeks before moving again to 1713 Lemmon Street,
    both of which had no peeling paint. There were no significant visitations to
    other properties for [Ms. Oglesby] during this time.
    In his report, Dr. Caplan set forth the dates and results of Ms. Oglesby’s BLL tests
    and explained that her BLLs were:
    4/19/99       2 mcg/dl       venous
    3/27/02       5.5 mcg/dl     venous
    8/20/04       4 mcg/dl       venous
    In forming his opinion about Ms. Oglesby’s exposure to lead at the property, Dr.
    Caplan relied on sources of information, not connected to Ms. Oglesby or Ms. Powell,
    showing the presence of lead in the building both before and after Ms. Oglesby’s residency.
    Specifically, Dr. Caplan reported that in October 1989 (nearly a decade before Ms. Oglesby
    - 38 -
    lived in the building), the Baltimore City Health Department issued an emergency violation
    notice for the building. According to Baltimore City Health Department records which
    were among the items reviewed by Dr. Caplan, the Health Department issued the violation
    notice for Apartment G-2 after determining that a child who visited the apartment had an
    abnormal BLL and an inspection of the apartment showed that it contained lead-based
    paint.
    Similarly, Dr. Caplan reported that in April 2011 (nine years after Ms. Oglesby
    moved from the building), Arc Environmental conducted inspections of multiple properties
    in the 2000 block of East North Avenue and found lead-based paint in seven of the
    properties. According to the Arc Environmental report, which was one of the items
    reviewed by Dr. Caplan, in April 2011, a lead-based paint inspection of Apartment 203 and
    other areas of the building resulted in findings that lead-based paint above the Maryland
    standard was detected on window jambs in the living room and in two bedrooms in
    Apartment 203 and in certain common areas of the building, including on the first-to-
    second floor rear stairs baluster and newel post and on the second-floor hallway window
    jamb.
    Dr. Caplan noted in his report that, in 2012 and 2014, Green Street Environmental
    analyzed the property and identified multiple areas containing lead-based paint. According
    to Green Street Environmental’s April 2012 report, the company tested components of the
    building for the presence of lead-based paint and found that 84 areas throughout the
    building contained lead-based paint. Green Street Environmental’s report showed that lead
    was found on every floor of the building in numerous locations, including in rooms that
    - 39 -
    would previously have been apartments. Green Street Environmental’s report and second-
    floor floorplan demonstrated that, of the rooms on the second floor that did not test positive
    for lead-based paint—namely, rooms 1 (a stairway), 2 (a hallway), 8 (a large area marked
    partly destroyed and inaccessible), and rooms 10 and 12 (potentially apartments in the
    past)—there were only three rooms, 8, 10, and 12, that could potentially have once been
    apartments; rooms 1 and 2 were a stairway and a hallway.
    Together, these three independent sources of information demonstrated that lead-
    based paint was present in the building before and after Ms. Oglesby lived there and
    supported Dr. Caplan’s conclusion that Ms. Oglesby was likely exposed to lead-based paint
    at the property during her tenancy in the building. The testing revealing the presence of
    lead in the building before and after Ms. Oglesby’s residency is particularly persuasive
    concerning the adequacy of the factual basis for Dr. Caplan’s opinion as to source
    causation. There is a lack of any evidence that the building underwent a lead-based paint
    abatement or gut rehabilitation after 1989, at some point before Ms. Oglesby’s residence
    in 1998. As the Appellate Court explained in Taylor v. Fishkind, 
    207 Md. App. 121
    , 144,
    148, 
    51 A.3d 743
    , 757, 759 (2012), cert. denied, 
    431 Md. 221
    , 
    64 A.3d 497
     (2013), when
    reviewing a trial court’s grant of summary judgment, “[i]f the property contained lead-
    based paint when it was originally constructed, then lack of evidence of a gut rehabilitation
    prior to [the plaintiff] living there would support the conclusion that the property still
    contained lead-based paint when [the plaintiff] lived there.” See also Rogers, 
    453 Md. at 272-73
    , 
    160 A.3d at 1219-20
     (same). In addition, our case law confirms that the federal
    government no longer permitted lead-based paint to be used after 1978, negating the
    - 40 -
    possibility that the property may have been entirely abated of lead-based paint at some
    point after the 1989 Health Department inspection results and repainted with lead-based
    paint after Ms. Oglesby’s departure in January or February 2002, thereby accounting for
    the 2011 and 2012 test results showing the presence of lead in the building. See Levitas,
    
    454 Md. at 248
    , 164 A.3d at 237.
    In addition to independent tests showing the presence of lead in the building, Dr.
    Caplan was aware, from sources other than Ms. Powell, that she and Ms. Oglesby were
    required to move out of the building because it was in poor condition. Dr. Caplan had
    reviewed the October 7, 2001 annual inspection report from Crowninshield for Apartment
    202 and, in his report, specifically noted that the annual inspection report indicated that
    multiple rooms in the apartment needed rehabilitation. At deposition, Dr. Caplan testified
    that the October 2001 inspection report “said that rehab was needed in multiple rooms:
    living room, dining room, bedrooms, bathroom[], kitchen and they were closing . . . that
    apartment building. . . . [T]he whole apartment building was closed at the beginning of
    2002 because of its poor condition.” The October 7, 2001 inspection report provided
    independent support for Dr. Caplan’s conclusion that lead was accessible and Ms. Oglesby
    was likely exposed to lead at the building.
    Prior to issuing his report, Dr. Caplan also reviewed Ms. Powell’s deposition
    testimony regarding chipping and peeling paint in the apartment and the rest of the
    building. At deposition, Ms. Powell described the building as having peeling and chipping
    paint everywhere in the building, throughout the hallways and stairwells and on the doors.
    Ms. Powell testified that, although approximately a year after she moved into the apartment
    - 41 -
    management repainted the building’s common areas and the apartment doors, the paint
    began peeling again. As to the apartment, Ms. Powell testified that the apartment was in
    poor condition when she first moved in, and that within six or seven months, she noticed
    peeling paint throughout the apartment, on the walls and windowsills, in the bathroom, and
    in a closet. Despite her request that management paint locations inside the apartment, only
    one window inside the apartment was repainted. This testimony, although it may have
    been disputed, contributed to the factual basis for Dr. Caplan’s opinion that lead was
    accessible to Ms. Oglesby during her residency at the building and that the building was a
    source of her lead exposure.
    Dr. Caplan also reviewed records documenting Ms. Oglesby’s BLL tests. At
    deposition, Dr. Caplan explained that the dates of Ms. Oglesby’s documented BLL tests,
    the circumstance that Ms. Oglesby’s BLL of 5.5 μg/dL was documented only two to three
    months after she moved away from 2000 East North Avenue, that she did not have
    significant visitations to other properties, and that she moved to a place not reported to
    have peeling and chipping paint led to his conclusion that it was very likely that 2000 East
    North Avenue was responsible for Ms. Oglesby’s BLL of 5.5 μg/dL.
    At bottom, although there may have been a dispute of fact concerning whether Ms.
    Oglesby was exposed to lead at the property or at other locations, there was more than an
    adequate supply of data and information about the building to support Dr. Caplan’s opinion
    that Ms. Oglesby was exposed to lead-based paint at 2000 East North Avenue. That Dr.
    Caplan did not rule out a property that Ms. Oglesby visited while living at 2000 East North
    Avenue or properties in which Ms. Oglesby lived before or after moving from the building
    - 42 -
    as sources of her exposure to lead would not render inadmissible his opinion regarding Ms.
    Oglesby’s exposure to lead 2000 East North Avenue being a significant contributing factor
    to her injuries. Cf. Levitas, 
    454 Md. at 250
    , 164 A.3d at 238 (“The substantial factor test
    does not require experts to exclude other properties as possible contributing sources. . . . It
    would be illogical for us to require an expert to narrow the plaintiff’s lead exposure down
    to a single source when the substantial factor test, by its very definition, permits more than
    one cause of injury.” (Citation omitted)); id. at 250, 164 A.3d at 238 (It is “not the rule”
    “that an expert must exclude other properties before he can testify that the plaintiff was
    exposed to lead at the subject property.”). With respect to source causation, “[w]e have
    only required that an expert be able to adequately explain how he determined that a
    property was a source of the plaintiff’s lead exposure so that the trier of fact can evaluate
    his reasoning.” Id. at 251, 164 A.3d at 238-39 (citation omitted).
    In fact, we agree with Ms. Oglesby that this case is similar to Levitas, id. at 250-51,
    164 A.3d at 238-39, in which we held that a trial court abused its discretion in excluding
    an expert’s opinion that the defendant’s property was likely a source of the plaintiff’s
    exposure to lead-based paint. In Levitas, id. at 248-49, 164 A.3d at 237, the expert took
    into account the circumstances that the plaintiff’s BLLs “were first found to be elevated
    while he was living at [the building], when he had not yet lived anywhere else[,]” and that
    he “regularly stayed at [the building] during the day while his mother was at work, both
    when he lived there and when he lived at” a subsequent residence. (Emphasis omitted).
    The expert also considered that: an Arc Environmental report found that 31 interior and 5
    exterior locations tested positive for lead; lead-based paint was federally banned in 1978,
    - 43 -
    making it unlikely that the building had been painted with lead-based paint since the
    plaintiff lived in the building in the 1990s; Maryland Department of Housing and
    Community Development records described the poor condition of the property; a Maryland
    Department of the Environment certification indicated that the building was not lead free;
    and the plaintiff’s family members testified that the building was in a deteriorated condition
    while the plaintiff lived there and the plaintiff touched peeling paint at the property. See
    id. at 248-49, 164 A.3d at 237. In Levitas, id. at 250-51, 164 A.3d at 238-39, we concluded
    that the trial court abused its discretion in excluding the expert’s testimony on causation
    because, in the trial court’s view, the expert had little information as to other sources of
    lead exposure. We explained that, in so ruling, the trial court mistakenly “relied on a
    purported rule of law that an expert must exclude other properties before he can testify that
    the plaintiff was exposed to lead at the subject property.” Id. at 250, 164 A.3d at 238.26
    Ms. Oglesby also sought to use Dr. Caplan’s testimony to assist with establishing
    26
    By contrast, in another case, Ross, 
    430 Md. at 663
    , 
    63 A.3d at 10
    , we held that a
    trial court did not abuse its discretion in determining that an expert lacked an adequate
    factual basis to opine that the defendant’s building was “the source” of the plaintiff’s
    exposure to lead-based paint. We concluded that the expert “did not explain adequately
    how she reached the conclusion that the [subject property] was ‘the source’ of the lead
    exposure that resulted in” the plaintiff’s elevated BLLs. 
    Id. at 664
    , 
    63 A.3d at 10
    . We
    explained that, “[g]iven the uncontroverted evidence that there were various other sources
    of lead exposure in [the plaintiff]’s environment, including her prior residence, and that
    she came to the [subject property] with already elevated [BLLs], there were likely multiple
    causes of her elevated [BLLs].” 
    Id. at 664
    , 
    63 A.3d at 10
    . We determined that “[t]he real
    question for the fact-finder [wa]s how much exposure to lead at the [subject property]
    contributed to [the plaintiff’s BLLs] over the pertinent time period[.]” 
    Id. at 664
    , 
    63 A.3d at 10
     (emphasis omitted). We concluded that the trial court did not abuse its discretion in
    determining that the expert’s opinion would not assist the fact-finder in answering that
    question. See 
    id. at 664-65
    , 
    63 A.3d at 10
    .
    - 44 -
    the second link, i.e., the link between her exposure to lead at the property and her BLLs.
    The information that Dr. Caplan relied on concerning the presence of lead-based paint in
    the building before and after Ms. Oglesby’s residency, and the deteriorated condition of
    the building and the apartment at the time that Ms. Oglesby lived there, giving Ms. Oglesby
    access to lead-based paint during the time she lived in the building, was sufficient to
    support the opinion that Ms. Oglesby was likely exposed to lead at 2000 East North
    Avenue. That information, coupled with Ms. Oglesby’s documented BLLs—specifically,
    that she had a BLL of 2 µg/dL in April 1999, only a few months after she moved into the
    building, and that she had a BLL of 5.5 µg/dL in March 2002, just two to three months
    after she moved out of the building—as well as information that Ms. Oglesby did not have
    significant visitations to other properties during this time and that the property Ms. Oglesby
    moved into did not have chipping and peeling paint, although disputed by the parties,
    provided a sufficient factual basis for Dr. Caplan to render an opinion concerning the
    second causal link, the link between specific exposure to lead at the property and Ms.
    Oglesby’s BLLs.
    Clearly, issues concerning the frequency of Ms. Oglesby’s visits to the Lafyette
    property on weekends and whether the Lafayette property and other properties that Ms.
    Oglesby lived in before or after residing at 2000 East North Avenue contained lead-based
    paint involve issues of disputed facts. The credibility of Ms. Powell’s testimony regarding
    the frequency and duration of Ms. Oglesby’s weekend visits and the condition of other
    properties is a matter for the trier of fact to determine, not the circuit court in ruling on the
    motion to preclude. See Frankel, 480 Md. at 700-01, 281 A.3d at 703. In other words,
    - 45 -
    subject to the premise that the jury would be made aware of the existence of any genuinely
    disputed facts, the information that Dr. Caplan relied on from Ms. Powell’s testimony
    provided a sufficient factual basis for his opinion linking Ms. Oglesby’s specific exposure
    to lead at the property to her documented BLL of 5.5 µg/dL in March 2002. See id. at 700-
    01, 281 A.3d at 703.
    Medical Causation
    Setting aside the issue of IQ loss, Dr. Caplan also had a sufficient factual basis to
    offer an opinion as to the third causal link—the link between Ms. Oglesby’s BLLs and her
    other alleged injuries—when concluding that Ms. Oglesby’s likely exposure to lead at 2000
    East North Avenue was a significant contributing factor to her cognitive impairments. Dr.
    Caplan pointed out in his report that, according to the United States Environmental
    Protection Agency, the American Academy of Pediatrics, the Maryland Department of the
    Environment, and the World Health Organization, lead is a causal or likely causal factor
    for the type of impairments Ms. Oglesby suffered. In this case, there is no challenge to the
    principle that the types of impairments and limitations documented by Dr. Hawkins-Heitt
    and Mr. Lieberman, which are described in Dr. Caplan’s report, can be caused by exposure
    to lead.
    In the motion to preclude, Respondents took issue with the factual basis for Dr.
    Caplan’s opinions as to causation of Ms. Oglesby’s alleged injuries, alleging that Dr.
    Caplan lacked a sufficient factual basis for his testimony because he relied on a “selective
    review of the evidence to support his opinion that the Property was the source of [Ms.
    Oglesby]’s childhood lead exposure, and that childhood lead exposure caused her injuries.”
    - 46 -
    Similarly, before this Court, Respondents advance the claim that “Dr. Caplan lacked a
    sufficient factual basis to opine that [Ms.] Oglesby suffered injuries as a result of lead
    exposure at the Property[,]” due to the “limited evidence that Dr. Caplan received from
    [Ms. Oglesby’s] counsel[.]” (Bolding omitted). In other words, as an extension of the
    argument that Dr. Caplan lacked an adequate supply of data for his opinion as to source
    causation, Respondents allege that Dr. Caplan also lacked an adequate supply of data for
    the opinion that Ms. Oglesby’s exposure to lead at 2000 East North Avenue was a
    significant contributing factor to her alleged injuries. We have already assessed this
    contention and dispensed with it; the record reflects that Dr. Caplan had more than an
    adequate supply of data for the opinion that Ms. Oglesby was exposed to lead-based paint
    at the property.
    That an expert have both an adequate supply of data and use reliable methodology
    are well-recognized aspects of having a sufficient factual basis for an opinion under
    Maryland Rule 5-702(3). See Sugarman, 
    460 Md. at 415
    , 
    190 A.3d at 354
    . In the
    “Introduction” section of the motion to preclude, Respondents asserted that “Dr. Caplan’s
    medical opinions, and any opinion testimony based on them, should be precluded under
    Maryland Rule 5-702” and the Frye-Reed standard “because they lack a sufficient factual
    basis and are not the product of a reliable methodology.”27 On brief in this Court,
    27
    In a section of the motion titled “Legal Standard,” along with other authority,
    Respondents cited general case law indicating that both an adequate supply of data and
    reliable methodology are necessary for the admission of expert opinion and that opinions
    based on conjecture and speculation are not admissible. And, Respondents quoted the
    well-established principle that “an expert opinion must provide a sound reasoning process
    - 47 -
    Respondents state that the circuit court properly exercised its discretion to find that “Dr.
    Caplan did not use a reliable methodology to form his opinions regarding Oglesby’s alleged
    injuries,” and state that the circuit court excluded Dr. Caplan’s opinions as “inherently
    unreliable.”
    To be sure, the record reflects that, at one point during the motions hearing while
    ruling, the circuit court stated that “there are issues, if you will, with the facts and the
    information that was gathered, and how it was gathered, and who he spoke to, and who he
    didn’t speak to[,]” and that “the basis of the Court’s ruling is not only when you combine
    those issues with the issue of the use of the methodology, the Court believes that together
    that makes his testimony and opinion inherently unreliable.” This was part of the circuit
    court’s response to Ms. Oglesby’s counsel’s request for clarification as to whether its ruling
    that Dr. Caplan had used “incorrect” information applied to Ms. Oglesby’s case or
    Johnson’s. With these remarks, the circuit court referred mainly to what it described as
    issues with the facts, which the court believed in combination with “the issue of the use of
    the methodology” rendered Dr. Caplan’s testimony unreliable. The circuit court made no
    finding whatsoever with respect to “the issue of the use of the methodology”28 and provided
    no substantive basis for ruling that Dr. Caplan’s testimony was inherently unreliable. This
    for its conclusion from the factual data” and the explanation for the opinion must not be
    “conclusory.” (Citation omitted).
    28
    Earlier, in its initial ruling, the circuit court’s only specific remarks concerning
    methodology referred to Dr. Caplan not using all available BLLs in formulating his IQ loss
    opinion and that he offered no support for the “calculations” he used.
    - 48 -
    was far from a finding by the circuit court that Dr. Caplan’s opinion on medical causation
    as to Ms. Oglesby’s other alleged injuries was the product of unreliable methodology.
    On brief in this Court, Respondents assert that Dr. Caplan’s opinion that Ms.
    Oglesby suffered “neurocognitive injuries” was inadmissible because he did not examine
    or administer tests to Ms. Oglesby, meet with her, or speak with her family, medical
    providers, or teachers. To the extent Respondents contend that Dr. Caplan’s opinions and
    testimony regarding Ms. Oglesby’s injuries are inadmissible because he relied on Dr.
    Hawkins-Heitt’s report and did not personally examine Ms. Oglesby, this goes to the
    weight to be given to Dr. Caplan’s opinion, rather than its admissibility. In Levitas, id. at
    251, 164 A.3d at 239, we rejected the defendant’s contention that an expert’s opinion
    lacked a sufficient factual basis because the expert did not conduct his own examination of
    the plaintiff and instead relied on another expert’s report, scientific research, school
    records, discovery materials, and deposition testimony. Our case law demonstrates that an
    expert’s factual basis may arise from a number of sources, including reports prepared by
    other doctors. See id. at 254, 164 A.3d at 240.
    When a challenge to the admissibility of expert testimony is raised, “[t]he burden
    rests with the proponent of the expert testimony to demonstrate that the[] requirements [of
    Maryland Rule 5-702] have been met.” Rochkind, 
    454 Md. at 286
    , 164 A.3d at 259
    (citation omitted).   In this case, we are satisfied that, with respect to the data and
    methodology used by Dr. Caplan for his opinion as to Ms. Oglesby’s alleged injuries (other
    than IQ loss), Ms. Oglesby has done so. The process that Dr. Caplan used in reaching his
    opinion is similar to that of medical experts who have been permitted in other cases to
    - 49 -
    render an opinion that a plaintiff’s exposure to lead was a significant contributing factor to
    impairments like those attributed to Ms. Oglesby. See, e.g., Levitas, 
    454 Md. at 251-55
    ,
    164 A.3d at 239-41. Dr. Caplan evaluated information such as Ms. Oglesby’s time of
    residency at the property, independent reports concerning the presence of lead and the
    condition of property, Ms. Oglesby’s documented BLLs, and medical and vocational
    evaluations describing Ms. Oglesby’s impairments, and, based on his knowledge and
    experience, provided a reasonable explanation of how the factual data led to his
    conclusions. See id. at 251-55, 164 A.3d at 239-41. Under the particular circumstances of
    this case, given the large quantity of data that he had available and reviewed and the nature
    of the challenge to the admissibility of his testimony, a remand for further proceedings as
    to Dr. Caplan’s opinion that Ms. Oglesby’s exposure to lead at the property was a
    substantial contributing factor to her injuries (other than IQ loss) is not warranted.
    II. Dr. Caplan’s Opinion with Respect to IQ Loss
    A. The Canfield and Lanphear Studies
    Respondents contend that Dr. Caplan’s testimony concerning Ms. Oglesby’s IQ loss
    is inadmissible because, in their view, Dr. Caplan’s explanation of his use of the Canfield
    and Lanphear studies does not support a finding that his methodology was reliable. On
    brief, Respondents state that “the issue is not the fact that Dr. Caplan relied on the Lanphear
    and Canfield studies; the issue is how Dr. Caplan used those studies to calculate [Ms.]
    Oglesby’s alleged IQ loss.”       (Cleaned up).     Based on their review of the studies,
    Respondents raise the following complaints: (1) the studies contain language indicating
    that causal inferences may not be made, and Dr. Caplan used linear calculations; (2) Dr.
    - 50 -
    Caplan used a peak BLL in a manner that is contradicted by information in the studies; and
    (3) he miscalculated Ms. Oglesby’s average BLL.
    To frame our discussion, we begin with some relevant information about the studies.
    The Canfield study “measured blood lead concentrations in 172 children at 6, 12, 18, 24,
    36, 48, and 60 months of age”—i.e., ½ a year old, 1 year old, and 1½, 2, 3, 4, and 5 years
    old. Richard L. Canfield, Charles R. Henderson, Jr., Deborah A. Cory-Slechta, Christopher
    Cox, Todd A. Jusko, and Bruce P. Lanphear, Intellectual Impairment in Children with
    Blood Lead Concentrations below 10 μg per Deciliter, 348 New Eng. J. of Med. 1517 (Apr.
    17, 2003), available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4046839/ [https://
    perma.cc/JV55-68C3]. The study explained that “[t]he relation between IQ and blood lead
    concentration was estimated with the use of linear and nonlinear mixed models, with
    adjustments for maternal IQ, quality of the home environment, and other potential
    confounders[,]” and that results demonstrated that “blood lead concentration was inversely
    and significantly associated with IQ.” Id. The study stated that, “[w]hen estimated in a
    nonlinear model with the full sample, IQ declined by 7.4 points as lifetime average blood
    lead concentrations increased from 1 to 10 µg[/dL].” Id.29 The Canfield study explained
    that “[p]revious research is consistent with the interpretation that the effects of lead on IQ
    are proportionally greater at lower lead concentrations.” 348 New Eng. J. of Med. at 1522.
    As to IQ at blood-lead concentrations below 10 µg/dL, the Canfield study related
    29
    The Canfield study also stated that, using the linear model, “the estimated IQ loss
    was 4.6 points for each increase in the blood lead concentration of 10 µg per deciliter,” and
    that “for children whose lead concentrations remained below 10 µg per deciliter, the
    estimated loss in IQ was considerably greater.” 348 New Eng. J. of Med. at 1521.
    - 51 -
    that “linear models for each lead variable were estimated for the subgroup of children
    whose peak lead concentration was below 10 µg per deciliter” and that, “[w]ithout
    exception, the estimates were larger in this subgroup.” Id. at 1521. The Canfield study
    stated that, using nonlinear mixed models, the “[s]emiparametric analysis indicated a
    decline in IQ of 7.4 points for a lifetime average blood lead concentration of up to 10 µg
    per deciliter[.]” Id.
    Similarly, the Lanphear study starts by noting that “[t]here is emerging evidence
    that lead-associated intellectual deficits occur at [BLLs less than] 10 µg/dL” and cites eight
    studies for this point. Bruce P. Lanphear, Richard Hornung, Jane Khoury, Kimberly
    Yolton, Peter Baghurst, David C. Bellinger, Richard L. Canfield, Kim N. Dietrich, Robert
    Bornschein, Tom Greene, Stephen J. Rothenberg, Herbert L. Needleman, Lourdes
    Schnaas, Gail Wasserman, Joseph Graziano, and Russell Roberts, Low-Level
    Environmental Lead Exposure and Children’s Intellectual Function: An International
    Pooled Analysis, 113 Env’t Health Persps. 894 (July 2005), available at https://www.ncbi.
    nlm.nih.gov/pmc/articles/PMC1257652/ [https://perma.cc/8LT6-NZZQ].                The study
    explained that it contacted investigators of the studies and obtained “data sets and
    collaboration” from seven of the eight. Id. The study described itself as a pooled analysis
    that estimated “the quantitative relationship between children’s performance on IQ tests
    and selected measures of blood lead concentration among children followed prospectively,
    from infancy through 5–10 years of age in seven prospective cohort studies.” Id. “To
    enhance comparability across studies, [the study] used the following blood sampling
    - 52 -
    intervals (based on children’s age): 6, 12 (or 15), 36, 48, and 60 months”—i.e., ½ a year
    old, 1 year old (or 1¼ years old), and 3, 4, and 5 years old. Id. at 895.
    As to results, the Lanphear study stated that, “[f]or the entire pooled data set,” there
    was an “observed decline of 6.2 IQ points [] for an increase in [BLLs] from < 1 to 10
    μg/dL[.]” Id. at 898. The Lanphear study stated that this “was comparable with the 7.4 IQ
    decrement for an increase in lifetime mean [BLLs] from < 1 to 10 μg/dL observed in the”
    Canfield study. Id. The Lanphear study stated that, consistent with other studies, “the
    lead-associated IQ deficits observed in this pooled analysis were significantly greater at
    lower blood lead concentrations.” Id. The Lanphear study also determined that, by using
    the larger sample size of the pooled analysis, it was able “to show that the lead-associated
    intellectual decrement was significantly greater for children with a maximal blood lead of
    < 7.5 μg/dL than for those who had a maximal blood lead of ≥ 7.5 μg/dL.” Id.
    B. Relevant Case Law
    This Court has held that “a properly qualified expert witness can rely on the
    Lanphear Study methodology, as well as other accepted scientific research, as a factual
    basis for an opinion that a plaintiff’s elevated BLLs caused the loss of a specific number
    of IQ points.” Sugarman, 
    460 Md. at 434
    , 
    190 A.3d at
    366 (citing Levitas, 
    454 Md. at
    254-
    55, 164 A.3d at 241; Roy v. Dackman, 
    445 Md. 23
    , 51 n.16, 
    124 A.3d 169
    , 186 n.16 (2015);
    Rochkind v. Stevenson, 
    229 Md. App. 422
    , 469-70, 
    145 A.3d 570
    , 598 (2016), rev’d, 
    454 Md. 277
    , 
    164 A.3d 254
     (2017)).
    In Roy, 
    445 Md. at 33
    , 
    124 A.3d at 175
    , we considered whether an expert witness
    could render an opinion that lead-based paint at a property caused the plaintiff’s medical
    - 53 -
    injuries, which included “a loss of IQ points, impaired attention, problems with memory,
    and problems with coordination.” (Cleaned up). The expert relied on the pooled Lanphear
    study to form an opinion about the plaintiff’s IQ loss due to lead exposure. See 
    id.
     at 51 &
    n.16, 
    124 A.3d at
    186 & n.16. The defendants took issue with the expert’s use of the study,
    contending that there “have been peer-reviewed studies published in highly respected
    journals not only directly contradicting the studies on which [the expert] relie[d], but also
    calling into question the application of the studies to any one individual without real-life
    evidence of actual IQ point loss.” 
    Id.
     at 51 n.16, 
    124 A.3d at
    186 n.16.
    We concluded that the expert’s reliance on the Lanphear study did “not invalidate
    the entire basis of his opinion, even if the Lanphear study [was] contrary to the results of
    other studies as alleged by [the defendants]. Such is the grist for cross-examination and
    dueling experts and for resolution by the relative weight assigned by the fact-finder.” 
    Id.
    at 51 n.16, 
    124 A.3d at
    186 n.16. We determined that the record demonstrated that the
    expert possessed “a sufficient background from which to provide an opinion as to the
    injuries claimed to have been suffered by [the plaintiff] as the result of alleged exposure to
    lead.” 
    Id. at 52
    , 
    124 A.3d at 186
    . But, whether a jury would find the expert’s testimony
    persuasive would “depend, in large measure, on the effectiveness of [the defendants’]
    cross-examination and a comparison/weighing by the jury against [the defendants’]
    competing witness(es)’ testimony.” 
    Id. at 52
    , 
    124 A.3d at 186
    .
    In Rochkind, 
    229 Md. App. at 465
    , 
    145 A.3d at 596
    , where an expert’s opinion
    quantified the plaintiff’s IQ loss, the Appellate Court addressed whether the expert’s
    calculations were reliable under Frye-Reed and whether the expert had an adequate factual
    - 54 -
    basis under Maryland Rule 5-702(3).30 The Appellate Court concluded that the trial court
    did not abuse its discretion in finding the expert’s methodology reliable where the expert
    extrapolated from the Lanphear study to estimate a specific IQ loss in the plaintiff. See
    Rochkind, 
    229 Md. App. at 469
    , 
    145 A.3d at 598
    . In Rochkind, id. at 466-67, 
    145 A.3d at 596-97
    , relying on the Lanphear study, the expert testified that the plaintiff lost between 5
    and 6 IQ points as a result of exposure to lead. The expert testified that, based on the
    Lanphear study, she used the plaintiff’s peak BLL of 14 μg/dL and “calculated an IQ loss
    of 3.9 points based upon a level of between zero and ten, 0-10 μg/dL[,] and an additional
    loss of 1.9 points for the level between 10 and 20 μg/dL, for a total of 5.8.” Id. at 466-67,
    
    145 A.3d at 597
    . The expert explained that her opinion would not have changed if she had
    used the plaintiff’s average BLL of 11.5 μg/dL. See id. at 466-67, 
    145 A.3d at 597
    .
    The Appellate Court determined that, because, as the defendant acknowledged,
    “there is a scientific consensus that lead poisoning causes IQ loss, the only issue [was]
    whether the trial court abused its discretion by allowing [the expert] to opine that [the
    plaintiff] sustained a specific IQ loss of between five and six points.” Id. at 469, 
    145 A.3d at 598
    . The Appellate Court concluded that the trial court did not abuse its discretion in
    accepting as “sound” the expert’s methodology of “extrapolating from epidemiological
    studies quantifying IQ loss resulting from lead exposure in the general population to
    30
    This Court reversed the Appellate Court’s judgment on a different ground,
    concluding that the trial court abused its discretion in permitting the expert to testify that
    lead exposure can cause attention-deficit/hyperactivity disorder (“ADHD”) generally and
    that lead caused the plaintiff’s ADHD specifically. See Rochkind, 
    454 Md. at 295-96
    , 164
    A.3d at 265. No issue concerning the expert’s opinion as to IQ loss was before this Court.
    See id. at 284-85, 164 A.3d at 258.
    - 55 -
    estimate the range of IQ loss in an individual.” Id. at 469, 
    145 A.3d at 598
    . The Appellate
    Court stated that the expert “fully explained the basis for her calculation on the IQ loss”
    during “vigorous cross-examination[.]” Id. at 470, 
    145 A.3d at 598
    . Accordingly, the
    Appellate Court concluded that the expert’s opinion as to IQ loss was supported by an
    adequate factual basis. See Rochkind, 
    229 Md. App. at 470
    , 
    145 A.3d at 599
    .
    In Levitas, 
    454 Md. at 254-55
    , 164 A.3d at 241, relying on Roy, we concluded that
    an expert could use the Lanphear study to calculate the plaintiff’s individual IQ loss. In
    Levitas, 
    454 Md. at 240
    , 164 A.3d at 232, at deposition, the plaintiff’s expert witness
    testified that, as a result of the plaintiff’s exposure to lead, the plaintiff lost 7.4 to 9.4 IQ
    points. In calculating the plaintiff’s IQ loss, the expert relied on the Lanphear study, and
    averaged the plaintiff’s BLLs and “determined his loss in IQ points based on the study’s
    results.” Id. at 240-41, 164 A.3d at 232. The trial court excluded the expert’s opinion,
    ruling that the expert lacked a sufficient factual basis under Maryland Rule 5-702(3). See
    id. at 241, 164 A.3d at 233.
    Before this Court, the defendant contended that the expert could not calculate the
    plaintiff’s “IQ loss using the Lanphear study because it is population-based, and therefore
    cannot be used to calculate an individual’s IQ loss.” Id. at 254, 164 A.3d at 240. Relying
    on Roy, 
    445 Md. at
    51-52 & n.16, 
    124 A.3d at
    185-86 & n.16, we rejected the defendant’s
    contention, stating that, despite other reputable studies contradicting the Lanphear study’s
    results and cautioning against using it to calculate individual IQ loss, relying on the
    Lanphear study did not invalidate the basis of an expert’s opinion. See Levitas, 454 Md.
    - 56 -
    at 254-55, 164 A.3d at 241.31
    In Sugarman, 
    460 Md. at 432-34
    , 
    190 A.3d at 365-66
    , after reviewing Roy,
    Rochkind, and Levitas, we stated unequivocally: “Levitas and Roy demonstrate that a
    properly qualified expert witness can rely on the Lanphear Study methodology, as well as
    other accepted scientific research, as a factual basis for an opinion that a plaintiff’s elevated
    BLLs caused the loss of a specific number of IQ points.” (Citations omitted). We
    explained that “[l]egitimate scientific disputes go not to the admissibility of testimony, but
    to the weight of the evidence.” Sugarman, 
    460 Md. at 434
    , 
    190 A.3d at 366
    . In Sugarman,
    
    id. at 403
    , 
    190 A.3d at 348
    , the plaintiff offered Robert Kraft, Ph.D., as an expert in the
    fields of psychology and neuropsychology, who conducted a neuropsychological
    examination of the plaintiff consisting of an interview and several tests to assess aspects of
    intelligence. Dr. Kraft testified that the plaintiff had a full-scale IQ of 94, which placed
    him in the average range, but noted that test scores “indicated that [the plaintiff] had some
    form of brain impairment.” 
    Id. at 403
    , 
    190 A.3d at 348
    .
    The plaintiff offered Jacalyn Blackwell-White, M.D., as an expert in the fields of
    pediatrics and childhood lead poisoning. See 
    id. at 405
    , 
    190 A.3d at 349
    . Dr. Blackwell-
    31
    In Levitas, 
    454 Md. at
    240 & n.6, 164 A.3d at 232 & n.6, following our first
    reference to the Lanphear study, we provided the citation for the Canfield study instead—
    “Richard L. Canfield et al., Intellectual Impairment in Children with Blood Lead
    Concentrations Below 10 µg per Deciliter, 348 New Eng. J. of Med. 1517 (2003).” It is
    unclear whether we inadvertently cited the Canfield study or whether we meant to refer to
    the Canfield study instead of the Lanphear study. In any event, in Levitas, 454 Md. at 254-
    55, 164 A.3d at 241, we summarized our discussion of the Lanphear study in Roy, 
    445 Md. at
    51-52 & n.16, 
    124 A.3d at
    185-86 & n.16, a case in which we provided the citation to
    the Lanphear study.
    - 57 -
    White reviewed the plaintiff’s medical records, Dr. Kraft’s report, and other records, and
    determined that the plaintiff incurred a brain impairment due to lead toxicity, that the
    impairment included a loss of cognitive function, and that the plaintiff lost 4 IQ points due
    to lead toxicity. See id. at 405, 
    190 A.3d at 349
    . Among other studies, Dr. Blackwell-
    White relied on the Lanphear study. See 
    id. at 405-06
    , 
    190 A.3d at 349
    .
    As to Dr. Blackwell-White’s opinion about the plaintiff’s IQ loss, we stated:
    Like the experts in Levitas and Roy, Dr. Blackwell-White relied on
    [the plaintiff]’s documented BLLs, the results of his neuropsychological
    evaluation, and the Lanphear Study, to estimate a specific IQ point loss. She
    did not look only to his elevated BLLs, assume he had a cognitive defect, and
    then extrapolate a point loss based on the Lanphear methodology. Rather,
    Dr. Blackwell-White relied on evidence that [the plaintiff]—individually—
    had already manifested cognitive defects. This gave her enough reason to
    use her knowledge and expertise to extrapolate a loss of IQ points according
    to the methodology outlined in the Lanphear Study. [The defendant]
    presented contradictory experts and extensively cross-examined [the
    plaintiff]’s experts about their conclusions. That is what we contemplated in
    Levitas and Roy.
    Sugarman, 
    460 Md. at 436-37
    , 
    190 A.3d at 367-68
     (citations omitted). We concluded that
    “Dr. Blackwell-White’s testimony provided sufficient evidence for the jury to draw the
    inference that, more likely than not, [the plaintiff]’s elevated BLLs caused a measurable
    loss of IQ points” and that the trial court properly denied the defendant’s motions and
    allowed the question to go to the jury. 
    Id. at 437
    , 
    190 A.3d at 368
    .
    The bottom line is that these cases demonstrate that experts have been permitted to
    rely on the Lanphear study and extrapolate from its findings and render an opinion that an
    individual suffered a specified loss of IQ points as a result of exposure to lead.
    - 58 -
    C. Application of Principles Above to This Case
    In this case, as with the experts in Sugarman, Levitas, and Roy, Dr. Caplan relied
    on information about Ms. Oglesby, such as documented BLLs, the results of the
    neuropsychological evaluation performed by Dr. Hawkins-Heitt showing that Ms. Oglesby
    had a full-scale IQ score of 80 and cognitive impairments, and the Lanphear study (as well
    as the Canfield study), to estimate specific IQ point losses. Cf. Sugarman, 
    460 Md. at 436
    ,
    
    190 A.3d at 367
    .       Although this Court and the Appellate Court have explicitly
    acknowledged that an expert may rely on and extrapolate from the Lanphear study to render
    an opinion as to an individual’s IQ loss, our case law has not yet assessed an expert’s use
    of the Canfield study in the same way. We note, though, that the Canfield study is one of
    the studies in the pooled analysis used in the Lanphear study. See 113 Env’t Health Persps.
    at 894. And, the Lanphear study explained that its conclusion that there was a decline of
    6.2 IQ points for an increase in BLLs from less than 1 to 10 μg/dL was comparable to the
    7.4 IQ decrement observed in the Canfield study. See id. at 898.
    At the outset of our discussion, we observe that Respondents raised in the motion to
    preclude, and on brief in this Court, arguments that appear to go to the reliability of Dr.
    Caplan’s methodology as well as arguments that are better suited for cross-examination,
    rather than the exclusion of Dr. Caplan’s testimony. As an example of the latter, at least
    with respect to the Lanphear study, Respondents identify a statement in the study that “[t]he
    observational design of this study limits our ability to draw causal inferences” and argue
    that this language renders Dr. Caplan’s opinion concerning Ms. Oglesby’s IQ loss
    inadmissible. That notwithstanding, as the case law discussed above demonstrates, experts
    - 59 -
    have been permitted to rely on the Lanphear study to offer an opinion that exposure to lead
    caused IQ loss to a plaintiff. See Sugarman, 
    460 Md. at 436-37
    , 
    190 A.3d at 367-68
    ; Roy,
    
    445 Md. at
    51 n.16, 
    124 A.3d at
    186 n.16. There is no dispute the Lanphear study shows
    that exposure to lead-based paint can cause IQ loss. See, e.g., Sugarman, 
    460 Md. at 430
    ,
    
    190 A.3d at 363
    . Our case law contradicts the notion that expert testimony as to specific
    causation in reliance on the Lanphear study is precluded based solely on the language in
    the study that Respondents point out and suggests that the significance of the language the
    Respondents point out is a matter for cross-examination. See Sugarman, 
    460 Md. at 434
    ,
    
    190 A.3d at 366
    ; Roy, 
    445 Md. at
    51 n.16, 
    124 A.3d at
    186 n.16.
    In another example of an argument better suited for cross-examination, Respondents
    assert that Dr. Caplan improperly multiplied using Ms. Oglesby’s peak BLL rather than
    her average lifetime BLL. Dr. Caplan’s testimony at deposition confirms that he made
    calculations based on both Ms. Oglesby’s peak BLL and the average of her BLLs.
    Although the Lanphear study states that “average lifetime estimates of lead exposure were
    generally stronger predictors of lead-associated intellectual deficits than” peak blood-lead
    concentration, 113 Env’t Health Persps. at 898, the Lanphear study did not state that an
    average BLL is the only predictor or that a peak BLL could not be used. And, in discussing
    IQ at blood-lead concentrations below 10 µg/dL, the Canfield study stated that “[l]ifetime
    average, peak, and concurrent blood lead concentrations, but not the average in infancy,
    were inversely and significantly associated with IQ[.]” 348 New Eng. J. of Med. at 1521.
    Neither study states that the average lifetime BLL is the only acceptable factor or indicator
    of lead exposure deficits. Moreover, case law demonstrates that expert witnesses, relying
    - 60 -
    on the Lanphear study, have been permitted to render an opinion as to IQ loss after
    extrapolating using either the average of a plaintiff’s BLLs, see Levitas, 
    454 Md. at
    240-
    41, 164 A.3d at 232, or a plaintiff’s peak BLL, see Rochkind, 
    229 Md. App. at 466-67
    , 
    145 A.3d at 597
    .
    Next, Respondents contend that Dr. Caplan incorrectly calculated Ms. Oglesby’s
    average BLL by not using the computation method set forth in the Canfield study. The
    Canfield study states:
    [L]ifetime average blood lead concentration was estimated at 3 and 5 years
    of age by computing the area under the blood lead curve (AUC) from 6
    through 36 months of age and from 6 through 60 months of age, respectively.
    Dividing the AUC by the corresponding age span yields an average
    concentration expressed in micrograms per deciliter.
    Respondents contend that Dr. Caplan did not perform the AUC calculation described in the
    Canfield study for Ms. Oglesby’s average BLL and instead that he took just the mean of
    the three BLL test results as the average, which, according to them, was wrong.
    Respondents do not make a corresponding allegation that the Lanphear study required the
    average BLL to be calculated in the same manner set forth in the Canfield study.32 With
    respect to the Canfield study, this issue would be among the matters for the circuit court’s
    consideration on remand should Ms. Oglesby seek to introduce Dr. Caplan’s testimony
    concerning her IQ loss at trial and Respondents raise the same objection.
    Respondents also argue that Dr. Caplan offered no support for using linear
    32
    The Lanphear study states that lifetime average blood lead concentration “was
    defined as the mean of blood lead tests taken from 6 months through the concurrent blood
    lead test.”
    - 61 -
    extrapolation, and observe that the Canfield study states that “the relation between
    children’s IQ score and their blood lead concentration is nonlinear.” 348 New Eng. J. of
    Med. at 1521-22. In our view, neither the Lanphear study nor the Canfield study sets forth
    one correct way in which to apply its findings. To the extent that Respondents argue that
    language in the Lanphear study does not permit linear extrapolation, as with the language
    concerning a potential limitation on causal inferences, this language has been in the study
    since its publication and, under Maryland case law, experts have been permitted not only
    to testify relying on the content of the Lanphear study, but also to render opinions as to
    specific IQ point loss after calculations based on information in the study.
    That said, although our case law demonstrates it is permissible for an expert to rely
    on the Lanphear study to offer an opinion that exposure to lead resulted in a specific loss
    of IQ points, the record in this case shows that neither Dr. Caplan’s report nor his deposition
    testimony fully explains the basis for his calculations under either study. To be sure, at
    deposition, Dr. Caplan testified that he made calculations using both Ms. Oglesby’s peak
    BLL of 5.5 μg/dL and an average BLL of 3.8 μg/dL. Implicit in the calculations is that Dr.
    Caplan determined that the Lanphear and Canfield studies indicate that every 1 μg/dL
    increase in a BLL leads to a loss of 0.62 or 0.74 IQ points, respectively. Dr. Caplan did
    not testify, however, that this interpretation of the studies’ findings formed the
    underpinning of his calculations.
    Further, assuming that Dr. Caplan, in fact, determined that the studies show that
    every 1 µg/dL increase in a BLL leads to a loss of 0.62 or 0.74 IQ points, it is not readily
    discernable from the content of the studies that these are reliable determinations, i.e., that
    - 62 -
    these are determinations reliably supported by information or findings in the studies. With
    respect to the Lanphear study, the issue is plainly not that Dr. Caplan used the study to
    make calculations or that he used information in the study and extrapolated to achieve a
    result. The question is whether his calculations involve use of information in the study in
    a way that produces reliable results. To be sure, the Lanphear and Canfield studies refer
    to losses of 6.2 or 7.4 IQ points, respectively, see 113 Env’t Health Persps. at 898; 348
    New Eng. J. of Med. at 1517, and it is possible Dr. Caplan’s approach is a reliable use of
    the information. But without a full explanation of his methodology, including the reasons
    for his choices, even though it is possible to discern the basis of the calculations, we cannot
    determine whether it was an abuse of discretion for the circuit court to preclude this aspect
    of Dr. Caplan’s testimony.
    It could well be that, once the parties have adduced additional information from Dr.
    Caplan concerning his use of the studies and the circuit court has been given an opportunity
    to assess his methodology, Dr. Caplan’s testimony with respect to Ms. Oglesby’s IQ loss
    based on one or both of the studies may be admissible. On remand, should Ms. Oglesby
    seek to introduce Dr. Caplan’s testimony concerning her IQ loss, the circuit court, at a new
    hearing, will have an opportunity to assess Dr. Caplan’s use of the studies and the reliability
    of his methodology. For these reasons, we remand the case for a hearing under Rochkind,
    
    471 Md. 1
    , 
    236 A.3d 630
    , for the circuit court to determine whether the calculations that
    Dr. Caplan employed using the Lanphear study are reliable and to assess Dr. Caplan’s use
    of the Canfield study and the reliability of his methodology with respect to it, should Ms.
    Oglesby seek to introduce evidence concerning her IQ loss at trial.
    - 63 -
    III. Summary Judgment Was Not Warranted
    Having concluded that the circuit court abused its discretion in granting the motion
    to preclude, we hold that the circuit court erred in granting summary judgment. The circuit
    court’s ruling that Ms. Oglesby was unable to prove negligence without Dr. Caplan’s
    testimony on causation was not warranted. Even without Dr. Caplan’s testimony (which
    should not have been excluded in its entirety), based on other evidence, Ms. Oglesby
    presented sufficient evidence that the property was a source of her exposure to lead to
    satisfy the first link of the causal chain. Dr. Caplan’s testimony, along with other evidence,
    satisfied the second and third causal links. In sum, Ms. Oglesby presented sufficient
    evidence that there was a reasonable probability, i.e., a fair likelihood, that the apartment
    at 2000 East North Avenue was a source of her exposure to lead-based paint and a
    significant contributing factor to her alleged injuries, other than IQ loss, to establish a
    prima facie case for negligence. See Rowhouses, Inc. v. Smith, 
    446 Md. 611
    , 657, 
    133 A.3d 1054
    , 1082 (2016).
    Expert testimony is not necessarily required to “rule in a property” as a source of
    exposure to lead. See 
    id. at 665-66
    , 
    133 A.3d at 1087
    ; Ross, 
    430 Md. at 669
    , 
    63 A.3d at 13
    . In Rowhouses, 
    446 Md. at 668
    , 
    133 A.3d at 1088
    , we held that the trial court erred in
    granting summary judgment in the defendant’s favor as to the plaintiff’s negligence claim
    because, even without direct evidence that the subject property contained lead-based paint
    and without expert testimony as to the source of the plaintiff’s lead exposure, “there was
    sufficient circumstantial evidence from which a trier of fact could conclude that the [subject
    p]roperty contained lead-based paint[.]” We determined that, for purposes of causation in
    - 64 -
    lead-based paint cases at the summary judgment phase, “a reasonable probability requires
    a showing that is less than ‘more likely than not,’ but more than a mere ‘possibility.’” 
    Id. at 655
    , 
    133 A.3d at 1080-81
     (footnote omitted). We concluded that, “in a lead-based paint
    case, a subject property is a reasonable probable source of a plaintiff’s lead exposure where
    there is a fair likelihood that the subject property contained lead-based paint and was a
    source of the lead exposure.” 
    Id. at 659
    , 
    133 A.3d at 1083
    .
    We explained that, “when proceeding under a Dow[33] theory of causation, where
    there is no direct evidence that a property contained lead-based paint, as a necessary part
    of the circumstantial evidence, the plaintiff must, by process of elimination, rule out other
    potential sources and demonstrate that the property at issue is the only source of exposure.
    See Rowhouses, 
    446 Md. at 659-60
    , 
    133 A.3d at 1083
    . As to ruling out other reasonably
    probable sources of lead, we stated that, “[a]t the summary judgment stage, although expert
    witness testimony may be helpful to rule out another property as a reasonable probable
    source, it is not necessary.” 
    Id. at 661
    , 
    133 A.3d at 1084
     (citation omitted).34 In contrast,
    33
    In Dow, 
    144 Md. App. at 76-77
    , 
    796 A.2d at 144-45
    , the Appellate Court held that
    the trial court erred in granting a motion for summary judgment where, in opposition to the
    motion, the plaintiffs set forth circumstantial evidence that, if believed, “could establish
    that the chipping and peeling paint inside [the subject property] was the only possible
    source of [the plaintiff]’s lead poisoning” and thus caused the plaintiff’s alleged injuries.
    34
    “[C]ircumstantial evidence that rules out other reasonably probable sources may
    take the form of a lay witness’s testimony at a deposition or an averment in an affidavit
    that a property other than the subject property did not contain deteriorated, chipping, or
    flaking paint and was in good condition.” Rowhouses, 
    446 Md. at 661
    , 
    133 A.3d at 1084
    .
    Or, a lay witness’s testimony or affidavit could rule out other reasonably probable sources
    of lead, including environmental sources such as soil, painted toys, and the like, by stating
    that the plaintiff did not have contact with such sources. See 
    id. at 661-62
    , 
    133 A.3d at 1084
    .
    - 65 -
    where a plaintiff produces direct evidence that a property contains lead, the ruling out of
    other potential sources, by expert testimony or otherwise, is not required. See, e.g.,
    Hamilton v. Kirson, 
    439 Md. 501
    , 536-37, 
    96 A.3d 714
    , 735-36 (2014) (Where there is no
    direct evidence that the subject property contained lead, the plaintiff “may prove
    circumstantially that the subject property contained lead-based paint in a number of
    ways[,]” including, but not limited to, relying on a Dow theory of causation by excluding
    other reasonably probable sources of lead.).
    In Rogers, 
    453 Md. at 256, 272-73
    , 
    160 A.3d at 1210, 1220
    , where without ruling
    out other possible sources of exposure, the plaintiff produced evidence, including a 1976
    positive test for lead at the subject property (20 years before his residency), we held that
    the evidence was sufficient to establish the subject property as a reasonably probable source
    of lead exposure and that summary judgment was improperly granted. We explained that
    “[t]he 1976 interior lead testing, paired with the lack of evidence showing full lead
    abatement, [gave] rise to a reasonable inference that [the subject property’s] interior still
    contained lead-based paint when [the plaintiff] lived there.” 
    Id. at 271
    , 
    160 A.3d at
    1218-
    19. We stated that, in a lead-based paint case, “a plaintiff is not required to show that one
    source of his lead exposure contributed to his injury to a greater degree than another” and
    that, “[o]nce a plaintiff has established a property as a reasonably probable source of his
    lead exposure, a defendant cannot avoid liability by pointing to other properties that also
    exposed the plaintiff to lead.” 
    Id. at 274
    , 
    160 A.3d at 1221
     (citation omitted).
    As Rowhouses, 
    446 Md. at 665-66
    , 
    133 A.3d at 1087
    , and Rogers, 
    453 Md. at 274
    ,
    
    160 A.3d at 1221
    , demonstrate, with direct evidence of lead in the building, Ms. Oglesby
    - 66 -
    did not necessarily need expert testimony to rule out other properties as reasonable
    probable sources where she produced sufficient admissible evidence to rule in 2000 East
    North Avenue as a reasonable probable source at the summary judgment stage. Because
    we hold that the circuit court abused its discretion in excluding Dr. Caplan’s opinion that
    Ms. Oglesby’s exposure to lead at the property was a significant contributing factor to her
    injuries other than IQ loss, there is sufficient evidence to establish a reasonable probability
    as to each of the links in the causation chain and to preclude summary judgment.
    IV. Conclusion
    For the reasons stated herein, we reverse the judgment of the circuit court and
    remand the case for trial or further proceedings under Rochkind, 
    471 Md. 1
    , 
    236 A.3d 630
    ,
    should Ms. Oglesby elect to present expert testimony as to IQ loss. As in Frankel, 480 Md.
    at 714-15, 281 A.3d at 711, in light of the findings made by the trial judge in ruling on the
    motions, this case should be assigned to a different trial judge for all further proceedings.
    JUDGMENT OF THE APPELLATE COURT OF
    MARYLAND REVERSED. CASE REMANDED
    TO THAT COURT WITH INSTRUCTION TO
    REMAND THE CASE TO THE CIRCUIT COURT
    FOR BALTIMORE CITY FOR TRIAL OR
    OTHER      FURTHER      PROCEEDINGS
    CONSISTENT   WITH    THIS    OPINION.
    RESPONDENTS TO PAY COSTS.
    - 67 -