Lead Opinion
Issues about an expert’s qualifications and foundation for his opinion are no strangers to appellate courts, and the complex issues of causation in lead paint cases generally require expert testimony, which is often challenged. Today we review a case in which the trial court excluded the plaintiffs
FACTS AND LEGAL PROCEEDINGS
Respondent Michael Christian was born on February 12, 1990, From his birth until October 1992, he resided with his mother, Nickolas Skinner (“Nickolas”), and grandmother, Betty Skinner (“Betty”),
Christian’s blood was tested eight times between November 1990 and October 1993. In April 1991, he exhibited an elevated free erythrocyte protoporphyrin (“FEP”) level, which does not measure a child’s blood lead level but is an initial screening test for lead exposure. From February 1992 to October 1993, Christian displayed elevated blood lead levels five times as follows:
Date Taken Blood Lend Level
February 20, 1992 9 µg/dL Spaulding
February 18, 1993 10 µg/dL Denmore
July 16, 1993 17 µg/dL Denmore
September 2, 1993 12 µg/dL Denmore
October 6, 1993 14 µg/dL Spaulding
[Editor’s Note: The preceding image contains the references for footnotes 3, 4]
During discovery, Christian designated Howard Klein, M.D., a pediatrician with experience treating lead-poisoned children, as an expert witness who would opine on the source of Christian’s lead exposure—source causation—and his lead-caused injuries—medical causation. As to the source of Christian’s lead exposure, Dr. Klein testified in his deposition that he was “of the opinion that [Christian] was exposed to lead-
In his expert report on medical causation, Dr. Klein concluded “within [a] reasonable degree of medical certainty” that lead caused Christian’s mental retardation, impaired cognition, and learning disabilities. He further opined in his deposition that as a result of Christian’s exposure to lead, he lost 7.4 to 9.4 IQ points. Dr. Klein based his opinion on: (1) a neuropsy-chological evaluation of Christian by Barry Hurwitz, Ph.D.; (2) Christian’s medical records; (3) Christian’s Answers to Interrogatories; (4) information on Spaulding and Denmore; (5) Christian’s Maryland Department of Health and Mental Hygiene (“DHMH”) lead testing records; (6) MDE records; (7) DHCD records; and (8) Christian’s school records. To calculate Christian’s IQ loss, he relied on the Lanphear study,
Levitas filed a motion to exclude Dr. Klein from testifying about source causation on the grounds that he lacked both the necessary qualifications and a sufficient factual basis for his opinion.
On July 10, 2013, the Circuit Court held a hearing on Levitas’s motion to exclude Dr. Klein. At the hearing, Levitas argued that Dr. Klein should be precluded from testifying about both source causation and medical causation. Ruling from the bench, the hearing judge excluded Dr. Klein’s testimony on both of these topics. The court reasoned that Dr. Klein should be prevented from testifying about the source of Christian’s lead exposure because “he did not, or had very little ... information concerning other sources [of lead exposure].”
In the first of two Court of Special Appeals opinions, the intermediate appellate court affirmed the Circuit Court’s decision to exclude Dr. Klein. Christian appealed to this Court, and we, in a per curiam order, vacated the judgment and remanded the case for reconsideration in light of Roy v. Dackman,
We granted certiorari to answer the following questions:
*243 1. Did the trial court err in excluding Dr. Klein’s testimony regarding lead-source causation?
2. Did the trial court err in excluding Dr. Klein’s testimony regarding medical causation?
Because we answer these questions in the affirmative, we shall affirm the judgment of the Court of Special Appeals.
STANDARD OF REVIEW
It is often said that decisions to admit or exclude expert testimony fall squarely within the discretion of the trial court. See, e.g., Bryant v. State,
Below we examine the Circuit Court’s rationale for excluding a crucial expert witness to assess whether it abused its discretion.
DISCUSSION
Levitas contends that the Circuit Court correctly excluded most of Dr. Klein’s testimony because he lacked a sufficient factual basis to opine about the source of Christian’s lead exposure and the nature and extent his injuries related to such exposure.
We have repeatedly explained that an expert may be qualified to testify if he “is reasonably familiar with the subject under investigation.” Roy,
An expert’s testimony is admitted “because it is based on his special knowledge derived not only from his own experience, but also from the experiments and reasoning of
Expert testimony must also have an adequate factual basis so that it is “more than mere speculation or conjecture.” Exxon Mobil Corp. v. Ford,
In assessing the expert-witness factors, the trial court is only concerned with whether the expert’s testimony is admissible. “[OJbjections attacking an expert’s training, expertise or basis of knowledge go to the weight of the evidence and not its admissibility.” Baltimore Gas & Elec. Co. v. Flippo,
Lead-Source Causation
The third factor in Rule 5-702—“sufficient factual basis”—garners the most debate between the parties. The Circuit Court restricted Dr. Klein’s testimony on the ground that he did not have a “substantial factual basis” for his opinion that lead inside Spaulding caused Christian’s elevated blood lead levels because he lacked “information concerning other possible sources.” Levitas asks us to affirm this ruling. Relying on Ross v. Housing Authority of Baltimore City,
By contrast, Dr. Klein concluded—with a reasonable degree of medical certainty—that Spaulding was a reasonably probable source of Christian’s lead exposure for several reasons:
• The 2012 Arc Report found that 31 interior locations and five exterior locations tested positive for lead;
• Lead paint was banned federally in 1978, and therefore it was unlikely that Spaulding had been painted with lead-based paint since Christian lived there in the 1990s;
*249 • DHCD records described the poor condition of the property;17
• An MDE certification indicated that Spaulding was not lead free;
• Christian’s FEP and blood lead levels were first found to be elevated while he was living at Spaulding, when he had not yet lived anywhere else;
• Family members testified that Spaulding was in a deteriorated condition while Christian was living there and that Christian touched peeling paint at the property; and
• Christian regularly stayed at Spaulding during the day while his mother was at work, both when he lived there and when he lived at Denmore.
Dr. Klein acknowledged that Denmore was also a source of Christian’s lead exposure. Thus, unlike the expert in Ross, he did not jump to the conclusion that Spaulding was a source merely because it contained lead paint.
The Dissent claims that expert witnesses in lead paint cases must exclude other properties to opine that a particular property was a substantial contributing factor to the plaintiffs injuries. Dissent Op. at 274-76,
The discretion accorded to trial judges in evidentiary rulings calls for an exercise of judgment using applicable legal standards. Neustadter,
Medical Causation
The first factor of Rule 5-702—qualification by knowledge, skill, experience, training, or education—comes into play as we consider the Circuit Court’s exclusion of Dr. Klein’s testimony about the cause of Christian’s injuries. Although the parties dispute the exact grounds for this ruling, our examination of the record reveals that the Circuit Court precluded Dr. Klein from testifying about Christian’s injuries both on the grounds that he was not qualified and that he lacked an adequate factual basis. We assess both grounds below.
Levitas takes issue with the factual basis for Dr. Klein’s opinion that lead poisoning caused “[m]ental [retardation” and “[impaired cognition” in Christian. He argues that Dr. Klein should have conducted his own examination of Christian, rather than relying on Dr. Hurwitz’s report, scientific research, Christian’s school records, discovery materials, and deposition testimony. This argument reflects Levitas’s misunderstanding about the nature of—and boundaries for— expert testimony.
In a leading case on expert witness qualifications, Rodman v. Harold, we held that the trial court erred in precluding an internal medicine specialist from testifying about the standard of care for a hysterectomy because he had not “performed any
We recently reiterated in Roy the principle from Rodman— that an expert witness is “not required necessarily to be a specialist” or have “specialized knowledge,” but her opinion must be based on “reliable knowledge, skill, and experience.” Roy,
The record in this qase establishes that Dr. Klein has the “knowledge, skill, experience, training, or education” required under Rule 5-702(1). During his deposition, Dr, Klein testified that he was an attending physician at the University of Maryland for 25 years, during which time he treated lead-poisoned children. Additionally, he testified that he helps doctors in Israel, where he now practices, rule out lead poisoning as a cause of illness. He is also well-acquainted with Centers for Disease Control and Prevention and American
The Circuit Court precluded Dr. Klein from testifying about Christian’s IQ loss on the grounds that he did not administer the “particular type of IQ test” that Dr. Hurwitz used in his own practice and he is “not able to explain to the jury how [ ] the psychologist got to [his] results.” But physicians are often knowledgeable about many tests, even those they do not use. Knowledge about a broad spectrum of available tests is part of the training received by a physician—and this knowledge need not be acquired through hands-on experience. Rodman,
Like Dr. Sundel, Dr. Klein developed his opinion based in part on Dr. Hurwitz’s neuropsychological evaluation of Christian. Moreover, the record reflects that Dr. Klein was indeed familiar with and had previously graded the IQ test. He testified in deposition that he was “familiar enough with [the IQ test] to know how the test was generated,” had seen several editions of different IQ tests, and “[knew] the testing pretty intimately.” In short, Dr. Klein had ample knowledge, training, and experience to be qualified as an expert under Rule 5-702(1). We see no sustainable reason why the trial court would conclude otherwise.
We next focus on whether Dr. Klein had a sufficient factual basis to testify as to Christian’s IQ loss. Levitas submits that the court properly excluded Dr. Klein’s testimony
As we have established, an expert can rely on facts and data “of a type reasonably relied upon by experts in the particular field in forming opinions or inferences upon the subject.” Md. Rule 5-703(a). An expert’s factual basis “may arise from a number of sources, such as 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.” Sippio v. State,
In Roy, Dr. Sundel also used the Lanphear study to calculate the plaintiffs individual IQ loss. The Roy defendants argued that the study could not provide a sufficient factual basis for Dr. Sundel’s IQ-loss opinion because other reputable studies contradicted the Lanphear study’s results and cautioned against using it to calculate individual IQ loss. Roy,
Finally, Levitas contends that Dr. Klein lacked a sufficient factual basis for his opinion that Christian has "impaired cognition” due to: (1) a 10-point difference between the IQ scores computed for Christian by Dr. Hurwitz and the defense expert; and (2) Dr. Klein’s acknowledgment that there is no evidence of Christian being diagnosed with an “attention impairment” or a learning disability.
Because Dr. Klein is competent to testify about lead-source causation and medical causation, the Circuit Court erred when it excluded his testimony. Therefore, we affirm the judgment of the Court of Special Appeals.
JUDGMENT OF THE COURT OF SPECIAL APPEALS AFFIRMED. COSTS TO BE PAID BY THE PETITIONER.
Getty, J., dissents.
Notes
. We use the Skinners’ first names to avoid confusion. We mean no disrespect.
. Respondent Michael Christian’s grandmother, Betty Skinner ("Betty’’), leased 3605 Spaulding Avenue ("Spaulding”) beginning in 1989. As of the date of her deposition on March 21, 2013, she still lived there.
. Blood lead levels are measured in micrograms per deciliter (µg/dL) of blood. See Standard Surveillance Definitions and Classifications, Centers for Disease Control and Prevention, https://www.cdc.gov/nceb/lead/ data/definitions.htm (last updated Nov. 18, 2016) [https://perma.ee/K4A 8-ZDKG], As of 2012, the Centers for Disease Control and Prevention considers blood lead levels greater than 5 pg/dL to be elevated. Id.
. We used the addresses and dates listed in Christian's Answers to Levitas's Interrogatories and Nickolas's deposition testimony as opposed to the addresses on the Maryland Department of Health and Mental Hygiene ("DHMH”) lab reports because this is the residential history Christian’s expert witness, Howard Klein, M.D., relied on when developing his lead source opinion. If we were to use the addresses on the DHMH lab reports, more of the reported elevated lead levels would correspond to his residence at Spaulding than at 4946 Denmore Avenue ("Denmore”). According to the lab reports, Christian lived at Denmore for the lead level reported on February 20, 1992 and lived at Spaulding for the three lead levels reported on February 18, July 16, and September 2, 1993.
. Christian also sued the owners of Denmore. His claims against them were dismissed with prejudice.
. 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).
. Levitas also moved to exclude the Arc Environmental, Inc. test results ("Arc Report”) and "any testimony related thereto.” The Circuit Court for Baltimore City denied this motion. Levitas has not appealed that decision.
. The Circuit Court excluded Dr. Howard Klein’s lead-source causation testimony because he lacked a sufficient factual basis for his opinion, not because he was not qualified to offer an opinion on the subject.
. When the Circuit Court’s written order was entered, it erroneously denied Levitas’s motion to exclude Dr. Klein. Levitas timely filed a motion for reconsideration, requesting that the court amend the order to reflect its ruling from the bench. The court granted Levitas’s motion.
. The parties entered into an agreement which provided that "[Christian] intends to appeal the order(s) excluding Dr. Klein’s testimony, arguing ... that [he] is qualified to offer testimony as to the source and cause of [Christianas injuries due to lead ingestion, and also that Dr. Klein had a sufficient factual basis for his testimony.”
.We have rephrased the two questions presented in Levitas’s Petition for a Writ of Certiorari. His Petition included the following questions:
*243 1. Whether the Court of Special Appeals erred in reconsidering all issues in this case when this Court's order for "reconsideration in light of Roy [v. Dackman,445 Md. 23 ,124 A.3d 169 (2015), reconsideration granted, (Nov. 24, 2015),]” should have only impacted the issue of expert qualifications.
2. Whether the trial court abused its discretion in excluding Dr. Klein's testimony where the record showed that Dr. Klein did not have a sufficient factual basis to support either his opinion as to the source of lead exposure or the cause and extent of Mr. Christian’s alleged injuries.
. Not all evidentiary rulings are reviewed for an abuse of discretion. Judge McDonald, writing for the Court, explained the applicable standards of review for these rulings in Mathews v. Cassidy Turley Maryland, Inc.,
Some matters, such as the weighing of the relevance of proffered evidence as against unfair prejudice or other considerations, are left to the “sound discretion” of the trial court. Such decisions will be reversed only for abuse of discretion. Other evidentiary rulings are based on a "pure legal question.” In those circumstances, an appel*244 late court considers the legal question without deference to the decision of the trial court.
Id. at 599,
. Levitas also argues that the Court of Special Appeals should have only reconsidered Dr. Klein's qualifications, and not the factual basis for his testimony. Specifically, Levitas contends that Roy "did not evaluate the factual basis underpinning the expert's opinions,” and therefore it has no bearing on the outcome of this case. Levitas misreads Roy. The Court found the plaintiff’s expert, Eric Sundel, M.D., competent to testify about the plaintiff’s injuries based on his "academic and experiential qualifications” and the materials he relied on. Id. at 49-52,
. This case implicates the first and third factors, although our discussion reverses that order.
. Levitas also relies heavily on City Homes, Inc. v. Hazelwood, 210 Md.App, 615,
. Evidence also showed that the plaintiff in Ross v. Housing Authority of Baltimore City,
. In Dr. Klein’s deposition testimony, he acknowledged that the Department of Housing and Community Development (“DHCD”) records were from after Christian lived at Spaulding. But given Betty’s and Nicholas’s testimony about the poor condition of Spaulding while Christian lived there and the lack of evidence of repairs in the intervening years, it was reasonable for Dr. Klein to consider these records.
. Levitas makes two additional points. He asserts that the Arc Report is not direct evidence of "lead paint hazards” while Christian lived at Spaulding, but merely evidence of the presence of lead at the property in 2012. He contends that there must be contemporaneous evidence of such hazards, like citations from the Baltimore Housing Department, for Dr. Klein to have a sufficient factual basis to conclude that Spauld-ing was a reasonably probable source of Christian’s lead exposure. We have never imposed such a requirement. Rather, the adequacy of an expert’s factual basis turns on whether he had a sufficient supply of data and a reliable methodology. Roy,
Levitas also claims that “Christian targeted [Spaulding], then provided Dr. Klein with information pertaining only to that property.” Levitas mischaracterizes the record. Dr. Klein's own report lists the records
. Dr, Sundel is the same expert the Court of Special Appeals held was properly excluded in Hazelwood. The Roy Court distinguished the record in that case from the record in Roy, noting that he had "endeavored to be more specific and shore-up the supposed deficiencies in his qualifications." Roy,
. We also acknowledged that the Lanphear study "has been cited to and discussed extensively by other studies employing similar tests relating to IQ loss and childhood lead poisoning.” Roy, 445 Md, at 51,
. Levitas claims that "Dr. Klein conceded that the results of Dr. Hurwitz’s evaluation of Christian were ‘suspect’ ” because Christian admitted to using marijuana and alcohol daily. Therefore, Levitas contends, Dr. Hurwitz’s report could not provide an adequate factual basis for Dr. Klein's testimony. Levitas has taken Dr, Klein's testimony out of context. Speaking only to marijuana use, Dr. Klein testified that the "memory function” portion of Dr. Hurwitz’s report "might be suspect.” This is grist for cross-examination and does not affect admissibility.
Dissenting Opinion
I respectfully dissent from the Majority’s conclusion that Howard Klein, M.D., the pediatrician expert witness offered by the Respondent, Michael Christian, offered a sufficient factual basis for his opinion that lead-based paint inside the property owned by Stewart Levitas, Petitioner, at 3605 Spaulding Avenue (“the Spaulding Property”), was a substantial factor cause of Mr. Christian’s harm from lead poisoning. See Majority Op. at 246-51,
Maryland courts have consistently held that an expert lacks an adequate factual basis for an opinion as to source causation in a lead paint case unless the expert can show an adequate supply of data and describe the methodology that enabled the
As Dr. Klein failed to provide a factual basis adequate to exclude the Denmore Property as a probable source of Mr. Christian’s harm, as required by Roy, and did not describe the methodology he used to reach his opinions as to lead source causation, I would affirm the trial court’s grant of the motion to exclude his testimony regarding lead source causation. Therefore, I respectfully dissent.
A. Causation in Lead Paint Litigation
When a plaintiff raises a negligence claim alleging injury from the presence of lead-based paint in a property owned by a defendant, the plaintiff bears the burden of proof for all essential elements of that claim, including “that the defendant’s negligence was a proximate cause of the accident or injury.” Hamilton v. Kirson,
This Court first applied the substantial factor test in a lead paint case in Ross v. Housing Authority of Baltimore City,
(1) the link between the defendant’s property and the plaintiffs exposure to lead; (2) the link between specific exposure to lead and the elevated blood lead levels, and (3) the link between those blood lead levels and the injuries allegedly suffered by the plaintiff. To be a substantial factor in causing [a plaintiffs] alleged injuries, the [subject property] must have been a source of [the plaintiffs] exposure to lead, that exposure must have contributed to the elevated blood lead levels, and the associated increase in blood lead levels must have been substantial enough to contribute to her injuries.
Ross,
A plaintiff may establish the required causation links in a lead paint case through either direct or circumstantial evidence. Id. at 527,
I dissented from this Court’s endorsement and application of a new theory of causation in Rogers. In part, that dissent was based on my view that, the proper standard of proof under which a plaintiffs case should be scrutinized at the summary judgment stage is whether the plaintiff has shown that it was “more probable than not” that a particular property was a substantial factor cause of his exposure to lead and elevated blood lead levels, as opposed to a “reasonable probability.”
The Majority in this case asserts that the standard which I described in my dissent in Rogers “stem[s] from a fundamental misunderstanding of the substantial factor test.” See Majority Op. at 250,
A plaintiff may certainly raise a claim under the substantial factor test that there was more than one cause of his harm. As I noted in a footnote in my Rogers dissent, in a lead paint negligence case a plaintiff may claim “that the defendant’s property is a contributing source of his harm from lead exposure, as part of a claim that multiple sources of lead exposure cumulatively proximately caused his harm.” Rogers,
In contrast, when a plaintiff only identifies a single property that he claims was the source of his exposure to lead and lead poisoning, but evidence before the trial court shows that there are other reasonably likely sources of that harm, the question before the trier of fact is not whether the defendant’s property was merely a contributor to some of his lead exposure along with the other cause(s) the plaintiff has identified. Rather, the issue becomes whether that property was, compared to the other reasonably likely causes, a substantial contributor to the plaintiffs lead exposure and consequent lead poisoning. In such a case, although the plaintiff does not need to show that a defendant’s property was the only contributing cause of his lead exposure and injury, he must show at least that the property was “an important or significant contributor to [his] injuries.” Rogers,
Expert Testimony and Causation
Under either a Dow or Kirson/Rogers theory of causation, a plaintiff can overcome summary judgment and place the issue of whether the defendant’s property caused the plaintiffs lead exposure and elevated blood lead levels before the trier of fact through a sufficient showing of direct or circumstantial evidence. Dow,
The standard for admissibility of expert testimony as to source causation is thus a vital one in lead paint actions. The Majority holds today that an expert who gives an opinion that a defendant’s property caused a plaintiffs harm does not need to show or explain that other reasonably probable sources did not cause the plaintiffs harm. Majority Op. at 250-51,
B. Factual Basis Requirement for Expert Opinion Testimony in Lead Paint Litigation
Maryland Rule 5-702 states 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.” A trial court “bases this determination on three factors,” one of which is “ ‘whether a sufficient factual basis exists to support the expert testimony.’ ” Id.
Maryland Rule 5-702’s requirement of an adequate factual basis is necessary to ensure that an expert’s testimony “constitutes more than mere speculation or conjecture.” Roy,
Maryland appellate courts have had several occasions in recent years to apply these principles in lead paint litigation to evaluate the adequacy of the factual basis supporting an expert opinion offered by a pediatrician as to source or source
Court of Special Appeals Cases
In Taylor v. Fishkind, the Court of Special Appeals considered whether a trial court had abused its discretion in granting summary judgment in favor of the defendant based upon a finding that the plaintiffs pediatrician expert witness, Dr. Henri Merrick, lacked an adequate factual basis as to his opinions regarding lead paint source and source causation.
The Court of Special Appeals determined that Dr. Merrick’s opinion that the property contained lead-based paint was “only supported by the age of the house and the presence of lead on one component of the exterior of the house.” Id. at 142,
The Court of Special Appeals considered a factually similar case in City Homes, Inc. v. Hazelwood, in which the plaintiffs pediatrician expert, Dr, Eric Sundel, testified that the property owned by the defendant “was the source of the [plaintiffs] lead exposure” and “a substantial contributing factor to injuries [the plaintiff] sustained.”
Court of Appeals Cases
In Ross v. Housing Authority of Baltimore City, this Court first addressed whether a pediatrician’s proposed expert opinion testimony that a defendant’s building was the source of the plaintiffs exposure to lead and harm from lead poisoning was supported by an adequate factual basis.
This Court affirmed the circuit court’s grant of a motion to exclude Dr. Blackwell-White’s testimony as lacking an adequate factual basis. Id. at 662-63,
Furthermore, we noted that because there was evidence in the record as to “various other sources of lead exposure in [the plaintiffs] environment,” there were multiple potential causes of the plaintiffs exposure and elevated blood lead levels, and thus “[t]he real question for the fact-finder is how much exposure to lead at the [defendant’s property] contributed to [the plaintiffs] [elevated] blood lead levels over the pertinent time period.” Id. at 664,
Prior to today’s opinion, this Court most recently addressed whether there was an adequate factual basis for a pediatrician expert’s opinion as to source and source causation in a lead paint case in Roy v. Dackman,
This Court held that the circuit court did not abuse its discretion in excluding Dr. Sundel’s testimony, concluding that there was not an adequate factual basis, and the “proposed opinion falls victim to the same problems as those discussed in Taylor and Ross.” Id. at 47,
Notably in Roy, we referenced our opinion in Kirson,
The Roy Court appeared to rest this distinction upon Rule 5-702’s statement that “[ejxpert testimony may be admitted ... if the court determines that the testimony will assist the trier of fact to understand the evidence or to determine a fact in issue.” As the Court explained, when there are multiple reasonably probable sources of the plaintiffs lead exposure, an expert opinion that does not explain why it was the defendant’s property that was a substantial factor that caused the plaintiffs harm, as opposed to another property, is “as likely to confuse as to assist a jury.” Id. at 48,
Factual Basis Standard for Causation Expert Opinions Offered In a Lead Paint Negligence Action
I distill from reviewing the above-described cases
C. Factual Basis in this Case
I agree with several portions of the Majority’s analysis with respect to the factual basis for Dr. Klein’s testimony as to source causation. Initially, I agree with the Majority that Dr. Klein did not lack an adequate factual basis for his opinion merely because he did not conduct an “independent investigation” or otherwise obtain first-hand knowledge of Mr. Christian or the properties at issue. It is true that Dr. Klein was not a treating physician, and that he had not seen or questioned Mr, Christian or his family members directly. He stated in his deposition testimony that all of his opinions in the report that he prepared for trial were based upon records that he had received from Mr. Christian’s counsel’s office. Additionally,
Furthermore, I agree with the Majority that Dr. Klein had adequate data to support his expert opinion that, to reasonable degree of medical probability, Mr. Christian “was exposed to lead-based paint at the [Spaulding Property].” As the Majority notes, there was substantial circumstantial evidence on which Dr. Klein relied in formulating that opinion:
Dr. Klein concluded—with a reasonable degree of medical certainty—that Spaulding was a reasonably probable source of Christian’s lead exposure for several reasons:
• The 2012 Arc Report found that 31 interior locations and five exterior locations tested positive for lead;
• Lead paint was banned federally in 1978, and therefore it was unlikely that Spaulding had been painted with lead-based paint since Christian lived there in the 1990s;
• [Department of Housing and Community Development] records described the poor condition of the property;
• A[ ] [Maryland Department of the Environment] certification indicated that Spaulding was not lead free;
• Christian’s [free erythrocyte protoporphyrin (“FEP”)] and blood lead levels were first found to be elevated while he was living at Spaulding, when he had not yet lived anywhere else;
• Family members testified that Spaulding was in a deteriorated condition while Christian was living there and that Christian touched peeling paint at the property; and
*272 • Christian regularly stayed at Spaulding during the day while his mother was at work, both when he lived there and when he lived at Denmore.
Majority Op. at 248-50,
However, Dr. Klein did not explain the methodology he used to assess that data and reach his conclusion that Mr. Christian was exposed to lead at the Spaulding Property. Instead, in both his report and his deposition testimony, he merely cited the “information that [he] took into account and then stat[ed]
Much more troubling, however, is that the Majority has overlooked the absence of any factual basis or methodology in support of Dr. Klein’s additional opinion that it was Mr. Christian’s exposure to lead-based paint at the Spaulding Property that was the substantial factor cause of his elevated blood lead levels and injuries from lead poisoning, as opposed to his period of residency at the Denmore Property, which Dr. Klein agreed was also a source of his exposure to lead. The Majority states that Dr. Klein did “not ignore[ ]” and “considered” information in the record as to the Denmore Property, referencing his report in which he stated that he considered “[property information for 3605 Spaulding Avenue [and] 4946 Denmore Avenue.” Majority Op. at 247-48 n.15, 250,
Based on the evidence in the record, Dr. Klein both failed to offer an adequate supply of data and failed to describe his methodology in support of his opinion that the Spaulding Property was the substantial factor cause of Mr. Christian’s elevated blood lead levels and harm from lead poisoning. Some
Relying on the Court’s suggestion in Kirson,
The Majority today is, therefore, overturning an express holding of this Court, less than two years from the date that holding was issued, in direct contravention of the principle of stare decisis. See e.g., DRD Pool Serv., Inc. v. Freed,
D. Conclusion
In summary, I would hold that when an expert witness is offered to show that a plaintiff was exposed to lead at a particular property, and that the exposure at that property caused the plaintiffs elevated blood levels and injury from lead poisoning, that expert meets the requirement in Maryland Rule 5-702 to show adequate factual basis only when he relies on more than “scant” circumstantial evidence, rules out other reasonably probable sources of the plaintiffs lead expo
The Majority’s holding that Dr. Klein was not required to exclude other probable sources of Mr. Christian’s lead poisoning is contrary to this Court’s prior holdings in Ross and Roy. Furthermore, the Majority’s holding will encourage trial courts to place the “imprimatur of court-endorsed expert status” on expert opinions that do not clearly establish that the defendant’s property was, more likely than not, a substantial factor cause of the plaintiffs harm, and thereby lead to confusion among jurors who are called to decide that very issue. See Ross,
For the above stated reasons, I would affirm the trial court’s grant of the motion to exclude Dr. Klein’s testimony regarding lead-source causation and, therefore, I respectfully dissent.
. In the context of lead paint litigation, the Court first distinguished a "reasonable probability,” which it equated to a “fair likelihood,” from a more stringent "more probable than not” standard in Rowhouses, Inc. v. Smith,
. After Ross was published, the Court of Special Appeals in Hamilton v. Dackman,
. Roy specifically refers to our "holding” in Kirson that "a lead poisoning case may succeed grounded on suitable circumstantial evidence as to source.” Id. However, the Kirson Court only supplied a dicta hypothetical to illustrate that a plaintiff may be able to establish circumstantially that a property contained lead-based paint. See Rogers,
. In addition to the cases described above, the Court of Special Appeals has held in Rochkind v. Stevenson that a trial court did not abuse its discretion by permitting a pediatrician expert to testify as to source causation in a lead paint case.
. The Majority is also correct in noting that Dr. Klein, unlike several of the experts in the cases discussed above, did not make the mistake of concluding solely or primarily from the age of the property that it must have contained lead paint, to which the plaintiff was exposed. See e.g. Taylor,