Opinion ID: 2642180
Heading Depth: 1
Heading Rank: 4

Heading: A.1. Weight-of-Evidence Characterization

Text: Using U.S. EPA’s revised draft 1999 Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1999), diesel exhaust (DE) is likely to be carcinogenic to humans by inhalation from environmental exposures. The basis for this conclusion includes the following lines of evidence: [1] strong but less than sufficient evidence for a causal association between DE exposure and increased lung cancer risk among workers in varied occupations where exposure to DE occurs; [2] extensive supporting data including the demonstrated mutagenic and/or chromosomal effects of DE and its organic constituents, and knowledge of the known mutagenic and/or carcinogenic activity of a number of individual organic compounds that adhere to the particles and are present in the DE gases; [3] evidence of carcinogenicity of DPM and the associated organic compounds in rats and mice by other routes of exposure (dermal, intratracheal, and subcutaneous and intraperitoneal injection); and [4] suggestive evidence for the bioavailability of DE organic compounds from DE in humans and animals. Diesel Engine Exhaust (CASRN N.A.) Integrated Risk Info. Syst., U.S. Envtl. Prot. Agency, http://epa.gov/IRIS/subst/0642.htm (last visited Nov. 8, 2013). 28 Dr. Goldstein reported data from a 1988 study by IARC, which found diesel exhaust “probably carcinogenic to humans (Group 2A).” It appears that after Dr. Goldstein’s testimony and report in 2011, IARC released a new study on June 12, 2012, which “classified diesel engine exhaust as carcinogenic to humans (Group 1), based on sufficient evidence that exposure is associated with an increased risk for lung cancer.” International Agency for Research on Cancer, World Health Org., IARC:Diesel Engine Exhaust Carcinogenic, (continued...) 50 Toxicology Program of the National Institutes of Environmental Health Science, and the American Conference of Certified Industrial Hygienists. Based upon his review and analysis of the literature on the subject, Dr. Goldstein opined that diesel exhaust can cause cancer in general. In determining whether diesel exhaust caused multiple myeloma, Dr. Goldstein focused his research on the polycyclic aromatic hydrocarbon chemicals that are found in diesel exhaust. After reviewing literature involving animal studies and the effects of polycyclic aromatic hydrocarbons, Dr. Goldstein found that polycyclic aromatic hydrocarbon, ingested through the lungs and carried through the bloodstream, can travel into bone marrow and impact blood forming organs that are responsible for the development of multiple myeloma. In other words, Dr. Goldstein opined that polycyclic aromatic hydrocarbons caused multiple myeloma.29 28 (...continued) http://www.iarc.fr/en/media-centre/pr/2012/pdfs/pr213_E.pdf (last visited on Nov. 8, 2013). 29 Dr. Goldstein made clear that no study that he reviewed stated definitively that polycyclic aromatic hydrocarbons caused multiple myeloma. His opinion was based upon the weight of the evidence. 51 Dr. Goldstein’s report set out an analysis of the degree to which Mr. Harris was exposed to diesel exhaust:30 In evaluating the risk posed to Mr. Harris by diesel exhaust in his work environment it is important to get some idea of the dose. Unfortunately no contemporaneous measures of relevant contaminants were made in the time before his diagnosis. . . . What I will therefore attempt to do is put the dose ratio into perspective by using available data (including anecdotal evidence) as well as guidelines for diesel exhaust proposed by the American Conference of Governmental Hygienists for a Threshold Value limit for diesel exhaust of 0.15mg/m3 (Time Weighted Average). It is intended to provide a perspective of the conditions when a train was dragging a full load uphill in an unvented tunnel. For this calculation I assume that the engines on Mr. Harris’ run were 3000 hp and met the exhaust standards of 0.6 g particulate matter and 1.0 g total hydrocarbons (PAH) per bhp­ hr for diesel engines manufactured between 1973 and 2001 (63 CFR 18997-19084, 16 Apr. 1998). Thus each locomotive in the consist taking 10-20 minutes to pass through one of the longer tunnels on the Allegheny and New River routes would have produced 300-600 g of particulate matter. Using Stretcher’s Neck for this example, the tunnel is 1588 feet long and the bore 30 Courts have recognized that in toxic tort cases it is generally difficult or impossible to quantify a plaintiff’s exposure to a toxin[.] [Therefore], [i]t is not always necessary for a plaintiff to quantify exposure levels precisely or use the dose-response relationship, provided that whatever methods an expert uses to establish causation are generally accepted in the scientific community. Nonnon v. City of New York, 932 N.Y.S.2d 428, 436-37 (N.Y. App. Div. 2011). 52 is 21' x 25 feet (estimated from photos of the tunnel), the tunnel has a volume of 30878 cubic yards. For a roughly 10-20 minute exposure the trainmen would have been in an environment of 9.7-19.5mg/yd3 of particulate matter, though the concentration in the engine cab would likely be less. To put this in perspective, the ACGLH proposed (subsequently withdrawn) a threshold limit of value 0.5-0.15mg/m3 (one m3 and one yd3 are essentially the same) time weighted average of particulate matter for an 8 hour workday in its recommendation. Using the 0.15mg/m3 value, Mr. Harris found himself surrounded by an environment that exceeded the proposed 8 hour average concentration limit by 65-to-130-fold. . . . .... It is my opinion that Mr. Harris through his employment by CSX was exposed to high levels of diesel exhaust, an agent determined by scientific and medical experts to be a probable or likely human carcinogen. Absent other factors, it can be reasonably concluded that this exposure was a major factor in his multiple myeloma. The weight of scientific and medical evidence from humans, animal studies, studies with tissues and cells using diesel exhaust, closely related pyrogenic materials and chemicals known to be in diesel exhaust supports this conclusion as does an understanding of the conditions under which Mr. Harris worked for 29 years. 3. Dr. Durie’s qualifications, methodology and opinion. Dr. Durie was called as an expert witness by Petitioner. Dr. Durie received a medical degree in 1966 from the University of Edinburgh Medical School, Edinburgh, Scotland. Dr. Durie has published approximately 400 peer reviewed articles in scientific journals, the majority of which involve multiple myeloma. He has been recognized as one of the top ten multiple myeloma 53 researchers in the world. Dr. Durie is board certified in internal medicine, hematology and oncology. From 1972-1992, Dr. Durie was on the faculty at the University of Arizona College of Medicine. Dr. Durie was on the faculty at Charing Cross and Westminster Medical School, University of London, from 1989-1992. From 1993 to the present, Dr. Durie has been the Director of Hematologic Research and Myeloma Programs at Cedars-Sinai Comprehensive Cancer Center at the University of California, Los Angeles (“UCLA”). During his career, Dr. Durie has spent roughly thirty years doing laboratory research involving multiple myeloma. Additionally, for many years, Dr. Durie prepared summaries of every article that was published on multiple myeloma and presented the material at the Annual Review of Medicine. Dr. Durie was retained in this litigation to render an opinion as to whether diesel exhaust caused multiple myeloma. Dr. Durie testified that he relied upon the Bradford Hill methodology to render his opinion. Dr. Durie reviewed reports by the Environmental Protection Agency, International Agency for Research on Cancer, and National Toxicology Program of the National Institutes of Environmental Health Science, which concluded that diesel exhaust 54 contained chemicals that were carcinogenic in humans, such as benzene and polycyclic aromatic hydrocarbons. He consulted a report linking diesel exhaust with multiple myeloma and epidemiologic literature concerning diesel exhaust and multiple myeloma. He reviewed animal studies involving exposure to benzene, polycyclic aromatic hydrocarbons and pristane. Dr. Durie reviewed the literature showing that benzene caused the loss of certain chromosomes, and that Mr. Harris suffered the same chromosomal damage. Dr. Durie testified that during his career, he has treated thousands of patients with multiple myeloma and that when he asked “them what their job is, it is amazing how frequently they’ll say they’re an engineer or that they’re working with chemicals. And so the occurrence of occupations where there is a risk of exposure is remarkably frequent.” Dr. Durie’s written report summarized his findings indicating the causal relationship of diesel exhaust and multiple myeloma as follows: [1] Martyn T. Smith and the group al-Berkley California have detailed the chromosomal changes linked to human benzene exposure. These chromosome changes include specific findings in the bone marrow myeloma cells from Ronald Harris. . . . Ronald Harris’s myeloma thus manifests a chromosomal pattern characteristic of benzene exposure. .... [2] The linage between diesel exhaust carcinogen exposure and the development of multiple myeloma in the case of Ronald Harris is thus both plausible and highly probable. 55 [3] Of note the more likely than not association between multiple myeloma and diesel exhaust exposure is supported by the known presence of multiple other toxic compounds in the exhaust [such as the] pristane chemical studied extensively by Michael Potter since the 1960’s and known to [have] induced plasmacytomata in mice (analogous to human multiple myeloma). Recent studies at UCLA have shown that pristane levels can be measured in vivo in humans and linked to immune regulatory dysfunction with increased B-cell activation. Myeloma is derived from abnormal B-lymphocytes. In addition, diesel exhaust contained many of the same polycyclic aromatic hydrocarbons found in coal tar and pitch blends both of which are known human carcinogens. Heavy metals such as nickel are also present with known carcinogenic potential. All this reinforces the plausible and probable causative relationship between diesel exhaust and the development of multiple myeloma. .... [4] I strongly support the fact that in the case of Ronald Harris the workplace exposures at CSX Transportation Inc. were more probably than not a causative factor in the development of multiple myeloma. 4. Dr. Shields’ qualifications, methodology and opinion. Dr. Shields was called as an expert witness by CSX. Dr. Shields received a medical degree in 1983 from Mount Sinai School of Medicine, New York. Dr. Shields has published approximately 154 peer reviewed articles in scientific journals. Dr. Shields’ area of expertise includes hematology and oncology. Dr. Shields is board certified in internal medicine and oncology. 56 From 1984-1989, Dr. Shields worked as a civilian physician at three medical facilities in Washington, D.C. Dr. Shields served as a commissioned officer in the United States Public Health Service Commissioned Corps from 1990-199931 and ultimately attained the rank of captain. From 2000 to the 2011, Dr. Shields was on the faculty at Georgetown University Medical Center. From 2006-2008, Dr. Shields was the senior medical director at Capital Breast Care Center in Washington, D.C. During the hearing in this case, Dr. Shields testified that he was now employed with the Ohio State University Comprehensive Cancer Center. Dr. Shields was retained by CSX to render an opinion as to whether diesel exhaust caused multiple myeloma. Dr. Shields testified that he relied upon the Bradford Hill methodology to render his opinion. Dr. Shields testified that he went on the internet to a website run by the National Institute of Health and researched articles dealing with diesel exhaust and multiple myeloma. Dr. Shields indicated that he reviewed twenty or more papers that involved railroad workers and cancers. Dr. Shields testified that he “inferred” from this data that 31 Commissioned Corps officers serve in a variety of positions throughout the United States Department of Health and Human Services and certain other federal agencies. See United States Pub. Health Serv. Commissioned Corps, U.S. Dep’t. of Health & Human Servs., http://www.usphs.gov/aboutus/mission.aspx (last visited on Nov. 8, 2013). 57 myeloma was not found in the studies because it was not mentioned. Specifically, Dr. Shields stated that “if myeloma was going to arise from the way they’re describing Mr. Harris’ exposure, these studies would show it.” Dr. Shields acknowledged that he was aware of a study that showed a significant association between myeloma and railroad workers. Dr. Shields discounted the study because, in his opinion, the study did not implicate diesel exhaust as a cause for any of the cancers. Several other studies linking myeloma and diesel exhaust were found not to be significant by Dr. Shields. Studies that showed an association between benzene and myeloma were also rejected by Dr. Shields as not significant to establish causation. Ultimately, Dr. Shields opined that, from his review of the literature, “there’s no evidence or there’s insufficient evidence that railroad workers are at increased risk of myeloma.” At the conclusion of Dr. Shields direct examination, counsel for CSX asked the following question: Q. Do you have an opinion as to whether the hypothesis in this case that exposure to diesel exhaust causes multiple myeloma has been proven? A. Yes. It’s my opinion that it – that it’s not been proven. 5. Dr. Green’s qualifications, methodology and opinion. Dr. Green was called as an expert witness by CSX. Dr. Green received a Ph.D. in food science and technology from the Department of Nutrition and Food Science at Massachusetts Institute of Technology in 1981. Dr. Green has published approximately 139 peer reviewed articles 58 in scientific journals. She is also the author of “In Search of Safety: Chemicals and Cancer Risk” (Harvard University Press 1988). Dr. Green’s area of expertise is toxicology. Dr. Green is a board certified toxicologist. Dr. Green was a research director of Scientific Conflict Mapping Project at Harvard University from 1983-1985. From 1985-1989, Dr. Green was employed at Meta Systems, Inc., as vice president of Environmental Health and Toxicology. From 1989 to the present, Dr. Green has been president of Cambridge Environmental, Inc. Dr. Green was retained by CSX to render an opinion as to whether diesel exhaust caused multiple myeloma. Dr. Green did not indicate any specific methodology that she used to render her opinion. However, her testimony suggests she followed the Bradford Hill methodology. Dr. Green testified that she does not know of any literature linking any type of cancer through the inhalation of pristane. Dr. Green also testified that neither the Environmental Protection Agency’s Health Assessment Document for Diesel Engine Exhaust nor the National Toxicology Program support the assertion that diesel exhaust causes myeloma cancer. Dr. Green found a study of Swedish workers by Dr. Paolo Bofetta was irrelevant, even though the study showed that over 800 workers exposed to diesel exhaust 59 contracted multiple myeloma. Dr. Green found the study was not significant because over 800 other men who were studied contracted multiple myeloma, but there was no evidence that they also were exposed to diesel exhaust. Dr. Green opined that “diesel engine exhaust might cause lung cancer, but there is no credible evidence that it causes multiple myeloma.” H. The Circuit Court’s Orders Excluding the Testimony of Petitioner’s Experts We have no hesitancy in finding that the opinions of Petitioner’s three experts regarding the causal link between diesel exhaust and multiple myeloma satisfy certain requirements of Rule 702. Their opinions would “assist the trier of fact to understand the evidence or to determine a fact in issue.” W. Va. R. Evid. 702. All three experts are witnesses “qualified as an expert by knowledge, skill, experience, training, or education.” Id. Additionally, the testimony of the experts was relevant to issues in the case. W. Va. R. Evid. 402. Thus, the question before us is whether the trial court abused its discretion in concluding that the reliability prong of Rule 702 was not met. That issue, properly framed, is whether Petitioner’s three experts used reliable methodologies in rendering opinions on the causation issue linking diesel exhaust with multiple myeloma. As we will explain, below, the trial court’s analysis exceeded this narrow issue. Instead, the court in rendering its ruling, addressed the jury question: Did Petitioner’s three experts prove causation? Because the trial court exceeded the scope of its narrow review of the reliability prong of Rule 702, we 60 find it necessary to examine cases that have demonstrated the narrow focus used to make the reliability determination. To begin, the court in King v. Burlington Northern Santa Fe Railway Co., 762 N.W.2d 24 (Neb. 2009), provided an excellent analysis of the limited gatekeeper role of trial courts. In King, the wife of a deceased former railroad employee brought an action seeking damages against the railroad under the Federal Employers’ Liability Act.32 The plaintiff alleged that her husband contracted multiple myeloma due to his exposure to diesel exhaust fumes while working for the railroad as a brakeman. The defendant moved the court to exclude the plaintiff’s expert. The opinion in King summed up the arguments and the trial court’s ruling as follows: Differing epidemiological studies supported the experts’ deposition testimony. [Plaintiff’s] expert, Dr. Arthur Frank, blamed [decedent’s] multiple myeloma on his exposure to diesel exhaust. Of course, [defendant’s] expert, Dr. Peter G. Shields, disagreed. He believed that the causes were unknown and that the majority of epidemiological studies failed to show that diesel exhaust can cause multiple myeloma. The district court sustained [defendant’s] motion to exclude Frank’s testimony, concluding that it failed to pass muster under our Daubert/Schafersman framework. It reasoned that his methodology was unreliable because the studies he relied on failed to conclusively state that exposure to diesel fuel exhaust causes multiple myeloma. 32 The plaintiff’s husband was the original plaintiff, but he died during the pendency of the litigation. 61 King, 762 N.W.2d at 31. After the trial court excluded the plaintiff’s expert witness in King, it granted summary judgment to the defendant. The plaintiff appealed to a Nebraska appellate court. The appellate court affirmed. The plaintiff then appealed to Nebraska’s Supreme Court. The high court in King reversed the ruling of the trial court after concluding that it applied an improper standard for reviewing the admissibility of expert testimony. The opinion in King outlined the following limited gatekeeper role of trial courts: Here, the parties do not dispute Frank’s qualification to give expert medical testimony or to interpret epidemiological studies. We see the broad issue as whether under our Daubert/Schafersman framework, Frank based his opinion on a reliable, or scientifically valid, methodology. . . . In determining the admissibility of an expert’s opinion, the court must focus on the validity of the underlying principles and methodology—not the conclusions that they generate. And reasonable differences in scientific evaluation should not exclude an expert witness’ opinion. The trial court’s role as the evidentiary gatekeeper is not intended to replace the adversary system but to ensure that an expert, whether basing testimony upon professional studies or personal experience, employs in the courtroom the same level of intellectual rigor that characterizes the practice of an expert in the relevant field. In sum, while the trial court acts as the evidentiary gatekeeper, it is not a goalkeeper. .... . . . Absent evidence that an expert’s testimony grows out of the expert’s own prelitigation research or that an expert’s research has been subjected to peer review, experts must show 62 that they reached their opinions by following an accepted scientific method or procedure as it is practiced by others in their field. Epidemiological statistical techniques for testing a causation theory have been subject to peer review and are generally accepted in the scientific community. The studies Frank relied upon were subject to peer review, and the researchers did not develop the statistical techniques used in the studies for this litigation. . . . Accordingly, the district court needed to consider only two issues regarding Frank’s opinion on . . . causation. Were the results of the epidemiological studies Frank relied on sufficient to support his opinion regarding . . . causation? And did he review the scientific literature or data in a reliable manner? In other words, did too great an analytical gap exist between the data and Frank’s opinion? .... We believe the district court erred in concluding that Frank’s causation opinion was unreliable because Frank could not point to a study that concludes exposure to diesel exhaust causes multiple myeloma. As explained, individual epidemiological studies need not draw definitive conclusions on causation before experts can conclude that an agent can cause a disease. If the expert’s methodology appears otherwise consistent with the standards set out above, the court should admit the expert’s opinion. But here, the court did not inquire into Frank’s methodology. King, 762 N.W.2d at 42-49 (internal quotations and citations omitted). Another case, though it did not involve multiple myeloma, which illustrates a trial court’s limited gatekeeper role is Milward v. Acuity Specialty Products Group, Inc., 639 F.3d 11 (1st Cir. 2011). In Milward, the plaintiffs, husband and wife, filed an action against 63 manufacturers of products used in refrigerators. The plaintiff husband worked as a refrigeration technician. The plaintiffs alleged that the husband contracted acute promyelocytic leukemia (“APL”) as a result of exposure to benzene that was contained in the defendants’ products. The trial court held a four day hearing to determine whether plaintiff’s expert on causation would be allowed to testify that benzene caused APL. The trial court, “in a detailed opinion, ruled that ‘Dr. Smith’s proffered testimony that exposure to benzene can cause APL lacks sufficient demonstrated scientific reliability to warrant its admission under Rule 702.’” Milward, 639 F.3d at 13. The trial court thereafter dismissed the action. The First Circuit Court of Appeals reversed after concluding that the trial court exceeded its discretion in finding that the opinion of plaintiffs’ expert was wrong. The First Circuit outlined the limited role of the trial court in deciding the admissibility of expert testimony: [T]rial courts are [not] empowered to determine which of several competing scientific theories has the best provenance. Daubert does not require that a party who proffers expert testimony carry the burden of proving to the judge that the expert’s assessment of the situation is correct. The proponent of the evidence must show only that the expert’s conclusion has been arrived at in a scientifically sound and methodologically reliable fashion. The object of Daubert is to make certain that an expert, whether basing testimony on professional studies or personal experience, employs in the courtroom the same level of intellectual rigor that characterizes the practice of an expert in the relevant field. So long as an expert’s scientific testimony rests upon good grounds, based on what is known, it should be tested by the adversarial process, rather than excluded for fear that jurors will not be able to handle the scientific complexities. Vigorous cross-examination, presentation of contrary evidence, and 64 careful instruction on the burden of proof are the traditional and appropriate means of attacking shaky but admissible evidence. .... . . . [T]he alleged flaws identified by the court go to the weight of Dr. Smith’s opinion, not its admissibility. There is an important difference between what is unreliable support and what a trier of fact may conclude is insufficient support for an expert’s conclusion. The court’s analysis repeatedly challenged the factual underpinnings of Dr. Smith’s opinion, and took sides on questions that are currently the focus of extensive scientific research and debate—and on which reasonable scientists can clearly disagree. In this, the court overstepped the authorized bounds of its role as gatekeeper. The soundness of the factual underpinnings of the expert’s analysis and the correctness of the expert’s conclusions based on that analysis are factual matters to be determined by the trier of fact. When the factual underpinning of an expert’s opinion is weak, it is a matter affecting the weight and credibility of the testimony—a question to be resolved by the jury. .... . . . The sum of Dr. Smith’s testimony was not merely that it is possible, or even biologically plausible, that benzene causes APL. Rather, the sum of his testimony was that a weighing of the Hill factors, including biological plausibility, supported the inference that the association between benzene exposure and APL is genuine and causal. The record clearly demonstrates that Dr. Smith’s opinion was based on an analysis in which he employed the same level of intellectual rigor that he employs in his academic work. In excluding Dr. Smith’s testimony, the district court did not properly apply Daubert and exceeded the scope of its discretion. We reverse the district court’s judgment for the defendants and 65 its exclusion of Dr. Smith’s testimony, and we remand for proceedings consistent with this opinion. Milward, 639 F.3d at 15-26 (internal quotations and citations omitted).. In Wagoner v. Exxon Mobil Corp., 813 F. Supp. 2d 771 (E.D. La. 2011), the plaintiff, widow and legal representative of decedent, filed a products liability action against manufacturers of benzene-containing products alleging that, as a result of the decedent’s exposure to benzene, the decedent contracted and died of multiple myeloma. The defendants filed motions to exclude plaintiff’s two causation experts. The basis of the motions, and the district court’s rejection of the same, were addressed by the court as follows: Defendants have raised five arguments with regard to the reliability of the testimony of Dr. Butler and Dr. Saux . . . : 1) their opinion rests on studies that do not show statistically significant findings; 2) their opinion relies on studies that do not examine benzene specifically; 3) their opinion rests on studies that are not published in peer-reviewed journals and are otherwise flawed; 4) their opinion reflects an incomplete review of the relevant literature; and 5) their opinion fails to articulate a biologically plausible mechanism for benzene to cause [multiple myeloma] and thus does not meet the Bradford Hill criteria. .... None of the arguments raised by Defendants in support of their motions to exclude Dr. Butler and Dr. Saux are persuasive. The two individuals are qualified to render an opinion . . ., and at least two studies support the notion that there is a statistically significant association between benzene and [multiple myeloma]. The fact that those studies may be flawed, that there are studies that cut against the two doctors’ opinion, 66 and that the doctors could not articulate a biologically plausible mechanism for benzene to cause [multiple myeloma] all go to the weight of their opinion, and not the question of admissibility. . . . Accordingly, the motions to exclude and for summary judgment must be denied. Wagoner, 813 F. Supp. 2d at 800-05. Finally, in Moreland v. Eagle Picher Technologies, 362 S.W.3d 491 (Mo. Ct. App. 2012), a Missouri appellate court addressed the admissibility of an expert opinion under its rules of evidence in the context of a workers’ compensation claim. The employee in Moreland alleged that he developed multiple myeloma as a result of years of inhalation of chemicals from plastics that his employer produced. The chemicals in the plastics included benzene, trichloroethylene, cadmium, nickel, and platinum. The employee produced an expert witness at the administrative level who testified that his exposure to benzene caused him to develop multiple myeloma. The employer called an expert witness who opined that benzene had never been proven to cause multiple myeloma. The ALJ found in favor of the employee and awarded him workers’ compensation benefits. An appellate court affirmed the award. In doing so, the appellate court in Moreland set out the following relevant discussion regarding the employee’s causation expert: Dr. Bernard Goldstein (“Dr. Goldstein”), a professor of medicine at the University of Pittsburg [sic] Graduate School of Public Health and School of Medicine, and also a physician, toxicologist, and hematologist, testified on behalf of Moreland. Dr. Goldstein testified he had studied benzene toxicity and published close to one hundred papers or reviews upon the 67 subject since the 1960s. Dr. Goldstein also specifically published and instructed members of the federal judiciary on issues concerning toxicology and, in particular, the issue of causation and whether chemical agents should be deemed to have caused or contributed to the development of multiple myeloma. Dr. Goldstein testified that benzene was reasonably probable to be a cause of multiple myeloma based upon epidemiological data, bioassays (experiments on laboratory animals), and mechanistic data. Dr. Goldstein testified that these sources of information are recognized by the International Agency for Research on Cancer and could be applied to substantiate that benzene caused multiple myeloma. . . . .... Dr. Goldstein testified that multiple myeloma is an identifiable disease and it is reasonably probable that exposure to benzene, either by air or dermal absorption, or both, is a substantial factor to cause the compounding of cells that lead [sic] to multiple myeloma. .... Here, [the employer] specifically argues only that Dr. Goldstein’s opinion is not based on medical certainty, and is not based on any medical or scientific facts that are reasonably relied upon by experts in the field of medical expertise. However, . . . Dr. Goldstein extensively explained many of the studies which show causation between benzene and multiple myeloma. Further, Dr. Goldstein testified that these sources of information are recognized by the International Agency for Research on Cancer and could be applied to substantiate that benzene causes multiple myeloma. Thus, the facts and data on which Dr. Goldstein based his opinions are a type reasonably relied on by experts in the field. 68 Accordingly, the Commission’s finding that Dr. Goldstein’s testimony meets the standard required of expert testimony was supported by competent and substantial evidence. Moreland, 362 S.W.3d at 500-04 (internal citations omitted).33 33 In the context of an administrative workers’ compensation claim, this Court addressed the issue of the reliability of evidence showing a link between benzene exposure and a cancer called chronic myelogenous leukemia. In Casdorph v. West Virginia Office Insurance Commissioner, 225 W. Va. 94, 690 S.E.2d 102 (2009), the claimant worked as an auto mechanic for the State Police for nearly twenty-two years. After the claimant was diagnosed with chronic myelogenous leukemia, he filed a claim for workers’ compensation benefits. (The claimant died while the case was pending at the administrative level). The claimant alleged that his cancer was caused by his exposure to benzene in the workplace. During a hearing before an ALJ the claimant provided evidence from several experts, including Dr. Infante, who testified that claimant “had ample opportunity for occupational exposure to benzene and other solvents contaminated with benzene due to his occupation and stated that benzene is the cause of leukemia and CML is a type of leukemia associated with benzene exposure.” Casdorph, 225 W. Va. at 102, 690 S.E.2d at 110. The ALJ found that the claimant developed chronic myelogenous leukemia from his exposure to benzene and therefore ruled the claim was compensable. The Board of Review reversed the decision of the ALJ. On appeal, this Court reinstated the ALJ’s decision. We concluded as follows: The medical literature and expert and fact witness testimony in this case sufficiently established that a causal link between the Appellant’s benzene exposure and CML existed. Although the Appellees assert that the case studies cited by Appellant showing a causal connection between benzene exposure and CML have not been able to get peer reviewed textbooks to acknowledge and print them as common or accepted consensus medical opinion, we find that these case studies, although small, are valid studies that have been peer reviewed and published. We acknowledge, as Appellees contend, that this Court recognized in State v. Leep, 212 W. Va. 57, 569 S.E.2d 133 (2002) that “whether a scientific theory is generally accepted within a scientific community” is a factor that must be weighed in determining whether to allow such testimony as evidence. However, we must also be reminded that (continued...) 69 The foregoing authorities consistently demonstrate the narrow scope of a trial court’s consideration of the admissibility of scientific expert testimony: [a] narrow focus that our cases have acknowledged, but which far too often has been misunderstood. Therefore, we believe it is necessary to carefully and clearly articulate our standard for reviewing the reliability prong of the admission of scientific expert testimony. Thus, we make clear, and so hold that, when a trial court is called upon to determine the admissibility of scientific expert testimony, in deciding the “reliability” prong of admissibility the focus of the trial court’s inquiry is limited to determining whether the expert employed a methodology that is recognized in the scientific community for rendering an opinion on the subject under consideration. If the methodology is recognized in the scientific community, the court should then determine whether the expert correctly applied the methodology to render his or her opinion. If these two factors are satisfied, and the testimony has been found to be relevant, and the expert is qualified, the expert may testify at trial. 33 (...continued) the Rules of Civil Procedure and the Rules of Evidence do not strictly apply to workers’ compensation claims. Casdorph, 225 W. Va. at 104-05, 690 S.E.2d at 112-13 (footnote added). It is important to note that the decision in Casdorph made clear that it was not evaluating the admissibility of the expert testimony under the standards of the rules of evidence, because those rules did not strictly apply to workers’ compensation litigation. Casdorph is distinguishable from Moreland in that regard because Missouri applies its rules of evidence to workers’ compensation litigation. 70 We wish to clarify that the standards outlined above are not new principles under this Court’s Daubert/Wilt jurisprudence. These principles have always been an implicit part of the Daubert/Wilt analysis. Simply put, however, these principles have not been clearly understood or followed by trial courts. For instance, this Court made the following observations in Wilt: We . . . are of the view that, under Rule 702, there is a category of expert testimony based on scientific methodology that is so longstanding and generally recognized that it may be judicially noticed, and, therefore, a trial court need not ascertain the basis for its reliability. Thus, we believe that Daubert is directed at situations where the scientific or technical basis for the expert testimony cannot be judicially noticed and a hearing must be held to determine its reliability. Wilt, 191 W. Va. at 46, 443 S.E.2d at 203. This limitation recognized in Wilt has been lost in practice. Litigants invariably have crowded trial court calendars with purported Daubert/Wilt evidentiary hearings whenever an expert is called to testify. This was never the intent of our Daubert/Wilt analysis. In Gentry v. Mangum, 195 W. Va. 512, 466 S.E.2d 171 (1995), Justice Cleckley attempted to clarify how Daubert/Wilt was to be applied by “giv[ing] circuit courts more guidance from a procedural standpoint in resolving scientific evidence issues.” Gentry, 195 W. Va. at 521, 466 S.E.2d at 180. Gentry pointed out in crystal clear terms that, 71 [a]ctually, most scientific validity issues will be resolved under judicial notice pursuant to Rule 201. Indeed, most of the cases in which expert testimony is offered involve only qualified experts disagreeing about the interpretation of data that was obtained through standard methodologies. Daubert/Wilt is unlikely to impact upon those cases. Therefore, circuit courts are right to admit or exclude evidence without “reinventing the wheel” every time by requiring parties to put on full proof of the validity or invalidity of scientific principles. Where judicial notice is appropriate, the circuit court should use it. Gentry, 195 W. Va. at 522, 466 S.E.2d at 181. In Syllabus point 4 of Gentry, Justice Cleckley simplified and reformulated our Daubert/Wilt standard as follows: When scientific evidence is proffered, a circuit court in its “gatekeeper” role under Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579, 113 S. Ct. 2786, 125 L. Ed. 2d 469 (1993), and Wilt v. Buracker, 191 W. Va. 39, 443 S.E.2d 196 (1993), cert denied, 511 U.S. 1129, 114 S. Ct. 2137, 128 L. Ed. 2d 867 (1994), must engage in a two part analysis in regard to the expert testimony. First, the circuit court must determine whether the expert testimony reflects scientific knowledge, whether the findings are derived by scientific method, and whether the work product amounts to good science. Second, the circuit court must ensure that the scientific testimony is relevant to the task at hand. 195 W. Va. 512, 466 S.E.2d 171. Gentry attempted to show that a full blown evedentiary Daubert/Wilt analysis was required only for evaluating a new and/or novel scientific methodology. Recognized methodologies are the subject of judicial notice. Moreover, this Court explained in Syllabus 72 point four of Mayhorn v. Logan Medical Foundation, 193 W. Va. 42, 454 S.E.2d 87 (1994), that [p]ursuant to West Virginia Rules of Evidence 702 an expert’s opinion is admissible if the basic methodology employed by the expert in arriving at his opinion is scientifically or technically valid and properly applied. The jury, and not the trial judge, determines the weight to be given to the expert’s opinion. See 2 Franklin D. Cleckley, Louis J. Palmer, Jr. and Robin Jean Davis, Handbook on Evidence for West Virginia Lawyers § 702.02[2][c] (5th ed. 2012) (“The [Daubert/Wilt] regime contemplates that trial judges will perform a gatekeeping function, determining whether the . . . methodology underlying proffered expert testimony is scientifically valid and whether that . . . methodology properly can be applied to the facts in issue.”). We note that we are not alone in limiting an evidentiary hearing to determine the reliability of experiments conducted for litigation and/or novel scientific methodology. See Nonnon v. City of New York, 932 N.Y.S.2d 428, 429 (N.Y. App. Div. 2011) (“[W]e [have] determined that plaintiffs’ expert evidence did not require that a hearing be held [because] neither the deductions of the expert epidemiologists and toxicologists, nor the methodologies employed by them, in reaching their conclusions are premised on . . . novel science[.]” (internal quotations and citations omitted)). The court in Nonnon observed that epidemiology and toxicology are hardly novel sciences, but rather, well-established and accepted methodologies. In such a case, the focus moves from the general reliability concerns . . . to the specific reliability of the procedures followed to generate 73 the evidence proffered and whether they establish a foundation for the reception of the evidence at trial. Nonnon, 932 N.Y.S.2d at 435. In the instant case, the trial court erred by holding a mini-trial to set out and resolve issues that were purely matters for jury consideration.34 The three orders excluding Petitioner’s three experts set out and resolved an array of disputed factual matters that were exclusively grist for the jury and which had no relevancy to the limited role the trial court had under the facts of this case. For instance, as noted by Petitioner, the orders found: 1. If a difference between a case group and control group is not statistically significant then there is no difference at all. 2. It is acceptable scientific practice to interpret as “not different” a study that shows an elevated risk that is not statistically significant. 3. There is substantially more benzene in cigarette smoke than diesel exhaust. 4. Benzene is present only in trivial doses in diesel exhaust. 5. The hypothesis that diesel exhaust causes multiple myeloma is confounded by the fact that cigarette smoking does not. 34 This Court is fully aware that litigants have abused the limited resources of our trial judges by demanding full-blown evidentiary hearings in most cases where expert testimony is offered. This opinion is intended to make unequivocally clear that the admissibility principles under Daubert/Wilt were never intended to allow the abuse that has become routine in our trial courts. 74 6. Most epidemiologic studies must be positive for purported causal association to be real. 7. Of forty-seven (47) studies of diesel exposed workers only eight (8) purport to be positive. 9. The epidemiologic literature investigating a causal association between railroad employment and multiple myeloma is null and not supportive of the subject hypothesis. 10. There are approximately ten (10) published studies investigating [sic] causal link between benzene and multiple myeloma. None of them are positive. 11. The epidemiologic literature regarding PAH exposure and multiple myeloma does not support the subject hypothesis. 12. IARC Technical Publication 42 was not intended to make a causation statement but to express a research agenda. 13. The general causation hypothesis that exposure to diesel exhaust causes multiple myeloma has not been proven. Clearly, the above findings made by the trial court should never have been considered as part of its limited gatekeeper role in this case. All of the above findings involve disputed opinions between the experts. They have nothing to do with the reliability of the methodologies used by the Petitioner’s experts. In fact, the trial court could have resolved the question of the relevancy and reliability of Petitioner’s experts through arguments by the parties and without their experts’ testimony. It is undisputed that the methodologies employed by Petitioner’s experts are recognized in the scientific community. Ironically, CSX’s experts relied upon the same methodologies. There is also no reasonable 75 dispute that Petitioner’s three experts employed the methodologies in a manner consistent with how they are employed in the scientific community. The only issue that was in dispute was whether Petitioner’s experts were correct in reaching the conclusions they reached. Challenging the latter issue is a matter for jury determination.35 We understand there will be cases where a party seeks to offer a new and novel methodology to explain causation, or where a party’s expert performed a specific experiment for trial to show causation. In either of those situations, the rigorous prong of the Daubert/Wilt gatekeeper analysis is implicated. In stark contrast, the experts in the instant case did not offer new or novel methodologies. The epidemiological, toxicological, weight of the evidence and Bradford Hill methodologies they used are recognized and highly respected in the scientific community. And, as is detailed in this opinion, those experts applied the methodologies consistently with the “level of intellectual rigor that characterizes the practice of an expert in the relevant field.” Milward, 639 F.3d at 15. 35 This Court is aware that some courts have excluded expert testimony on the issue of whether multiple myeloma is caused by diesel exhaust. See Aurand v. Norfolk S. Ry. Co., 802 F. Supp. 2d 950 (N.D. Ind. 2011) (excluding plaintiff experts on multiple myeloma); Morin v. United States, 534 F. Supp. 2d 1179 (D. Nev. 2005) (same); Castellow v. Chevron USA, 97 F. Supp. 2d 780 (S.D. Tex. 2000) (same); Estate of Mitchell v. Gencorp, Inc., 968 F. Supp. 592 (D. Kan. 1997) (same); Sutera v. Perrier Grp. of Am. Inc., 986 F. Supp. 655 (D. Mass. 1997) (same); Richardson v. Union Pac. R.R. Co., 386 S.W.3d 77 (Ark . Ct. App. 2011) (same); Missouri Pac. R.R. Co. v. Navarro, 90 S.W.3d 747 (Tex. Ct. App. 2002) (same). The decisions of the courts in those cases are inconsistent with the standards of admissibility of scientific expert testimony that are followed in this jurisdiction. 76