RICHARD W. ROBERTS, District Judge.
Plaintiffs, approximately 2,000 Ecuadorian citizens and domiciliaries, bring common law negligence and other tort claims against the DynCorp defendants, alleging acute and chronic personal injuries caused by the defendants spraying herbicides over the plaintiffs' lands in Ecuador.
The Department of State ("DOS") hired the defendants to help eradicate Colombian cocaine and heroin poppy plantations. Arias v. DynCorp, 856 F.Supp.2d 46, 49 (D.D.C.2012). To carry out the mission, which was known as "Plan Colombia," the defendants' planes sprayed aerial fumigants over Colombian drug farms. The fumigant was a glyphosate-based herbicide. Am. Compl. ¶ 35. "Commercial versions of the herbicide have been sold under the trade name Roundup®." Id. However, the planes' fumigants allegedly also drifted onto the plaintiffs' lands in Ecuador, harming "humans, animals, and plants other than cocaine and opium poppies[.]" Arias, 856 F.Supp.2d at 49 (internal citation and quotation marks omitted). These fumigations are alleged to have severely damaged the plaintiffs and their property and, as a result, forced those residing in the affected areas to flee. Id. The test plaintiffs reported several acute injuries including "itchiness to the skin, nose, and eyes; skin irritation; burning sensation to the skin and eyes; rash; vomiting; respiratory problems; headaches; dizziness; stomach aches; diarrhea; and burning throat." Pls.' Opp'n to DynCorp's Mot. to Exclude the Opinions of Pls.' Expert Dr. Michael Wolfson & Associated Mot. for Summ. J. ("Pls.' Opp'n"), Ex. 1 (Michael A. Wolfson Expert Rpt. ("Wolfson Rpt.") at 3). The plaintiffs now bring common law tort claims and claims under the Alien Tort Claims Act against the defendants, all arising from injuries the fumigants allegedly caused.
The plaintiffs proffer as an expert Dr. Michael A. Wolfson to offer opinion testimony in several areas. First, he would state that the DynCorp defendants applied the Plan Colombia herbicide in a manner contrary to the directions on the Roundup label. Second, Dr. Wolfson would offer testimony linking general and specific causation of the plaintiffs' acute personal injuries to their alleged exposure to the Plan Colombia herbicide. See Pls.' Opp'n at 2. Third, Dr. Wolfson would opine that as a result of the plaintiffs' exposure to the Plan Colombia herbicide, the plaintiffs have an increased risk of developing several cancers, including non-Hodgkin's lymphoma, hairy cell leukemia, and multiple myeloma. Wolfson Rpt. at 3. Given the plaintiffs' risk of future adverse health effects, Dr. Wolfson would also testify that the plaintiffs should be provided with medical monitoring for early detection of cancer. Id. at 4.
Dr. Wolfson received his Masters of Science in Pharmacology from Northeastern University and holds a medical degree from State University of New York Upstate Medical Center and a Masters of Public Health from Harvard School of Public Health. Wolfson Rpt., Ex. A. at 1. Dr. Wolfson is "Fellowship-trained and Board Certified in Occupational Medicine (1995) with clinical training in occupational and environmental medicine," and has "engaged
The DynCorp defendants move to exclude Dr. Wolfson's expert testimony. The defendants argue that Dr. Wolfson is not qualified to offer his three opinions and that his opinions are unreliable. Defs.' Mot. at 1-3. The defendants further move for summary judgment arguing that in a toxic tort case, expert testimony is necessary to prove causation. They argue that if Dr. Wolfson's testimony is excluded, the defendants are entitled to judgment as a matter of law.
Federal Rule of Evidence 702 provides:
Fed.R.Evid. 702.
Under Rule 702, district courts are gatekeepers of expert evidence. See Daubert v. Merrell Dow Pharm., Inc., 509 U.S. 579, 589, 113 S.Ct. 2786, 125 L.Ed.2d 469 (1993). The trial judge must determine as an initial matter whether the proffered witness is qualified to give the expert opinion he seeks to express. See Kumho Tire Co. v. Carmichael, 526 U.S. 137, 156, 119 S.Ct. 1167, 143 L.Ed.2d 238 (1999); Daubert, 509 U.S. at 589, 113 S.Ct. 2786. To do so, the court must assess whether the proffered expert has "sufficient specialized knowledge to assist the jurors in deciding the particular issues in this case." Kumho, 526 U.S. at 156, 119 S.Ct. 1167 (internal quotation marks omitted). Although "a person who holds a graduate degree typically qualifies as an expert in his or her field," formal education in the subject or field is not a prerequisite to testify as an expert. Khairkhwa v. Obama, 793 F.Supp.2d 1, 11 (D.D.C.2011); see also Fed.R.Evid. 702 (stating that an expert may be qualified by "knowledge, skill, experience, training, or education" (emphasis added)). A proffered witness who does not hold a specific academic degree may be qualified as an expert if he has some degree of specialized knowledge regarding the subject or a similar topic. See Dyson v. Winfield, 113 F.Supp.2d 44, 50 (D.D.C. 2000) ("[T]he key to qualifying him as an expert is his knowledge, not his academic degree."); see also Exum v. Gen. Elec. Co., 819 F.2d 1158, 1163-64 (D.C.Cir.1987). A witness may also be qualified as an expert based on his experience. "If the witness is
Rule 702 also places an obligation on the court to "ensure that any and all scientific testimony or evidence admitted is not only relevant, but reliable." Daubert, 509 U.S. at 589, 113 S.Ct. 2786. Evidence is relevant if it will "`assist the trier of fact to understand the evidence or determine a fact in issue.'" Id. at 591, 113 S.Ct. 2786 (quoting Fed.R.Evid. 702).
Scientific testimony is reliable when it pertains to scientific knowledge. Id. at 589-90, 113 S.Ct. 2786. Determining whether the testimony pertains to scientific knowledge
Meister v. Med. Eng'g Corp., 267 F.3d 1123, 1127 (D.C.Cir.2001). Accordingly, scientific knowledge requires that the "inference or assertion must be derived by the scientific method." Daubert, 509 U.S. at 590, 113 S.Ct. 2786. That is, the "[p]roposed testimony must be supported by appropriate validation — i.e., `good grounds,' based on what is known." Id. In determining whether the grounds supporting the expert testimony are scientifically valid, courts may consider "whether the theory or technique had been tested, whether it had been subjected to peer review and publication, the method's known or potential error rate, and the method's general acceptance in the scientific community." Meister, 267 F.3d at 1127 (citing Daubert, 509 U.S. at 593-94, 113 S.Ct. 2786).
The plaintiffs assert that Dr. Wolfson is qualified to offer an expert opinion that the Plan Colombia herbicide contained "excessive concentrations of glyphosate and surfactant[,]" Wolfson Rpt. at 3; Pls.' Opp'n, Ex. 2 (Michael A. Wolfson Rebuttal Rpt. ("Wolfson Rebuttal Rpt.") at 7), because he is a physician and a specialist in occupational and environmental medicine, Pls.' Opp'n at 5. Although Dr. Wolfson has impressive credentials, the plaintiffs have not demonstrated how his academic and professional experiences make him qualified to testify as to the proper concentration of glyphosate and surfactant in the Plan Colombia herbicide and application rate of the herbicide. Dr. Wolfson's expert report states that he has graduate degrees in pharmacology and public health and a medical degree. Wolfson Rpt., Ex. A at 1. The plaintiffs in their opposition simply recite Dr. Wolfson's degrees. Pls.' Opp'n at 5. But nothing the plaintiffs provide reflects that Dr. Wolfson's education was related to herbicides, weed biology or eradication, glyphosate, or a related field.
As to whether Dr. Wolfson's experience makes him qualified, the plaintiffs have not demonstrated that Dr. Wolfson's experience is a "sufficient basis" for his expert opinion.
Moreover, the way that Dr. Wolfson concluded that the Plan Colombia herbicide contained excessive concentrations of glyphosate and surfactant and was applied at an excessive rate makes his expert opinion testimony improper and inadmissible. Dr. Wolfson's opinion that the Plan Colombia herbicide contained excessive concentrations of glyphosate and surfactant is based on a comparison of the Plan Colombia herbicide composition and application rate with the manufacturer's recommended concentrations and application directions
There are also at least two factors undermining the reliability of Dr. Wolfson's proposed testimony. First, Dr. Wolfson admits that the Roundup Ultra label provided the sole basis for his opinion that the concentration of glyphosate and surfactant in the Plan Colombia herbicide and its application rate was excessive. Wolfson Dep. at 71:22-72:20, 78:23-79:8. However, Dr. Wolfson did not use all of the relevant information on the label in reaching his conclusion. Instead, he based his opinion on incomplete excerpts from the label. For example, Dr. Wolfson would testify that the application rate of the glyphosate based herbicide used in the Plan Colombia spraying was excessive based on the Roundup Ultra label which, according to Dr. Wolfson, states that Roundup Ultra use should not exceed 1 quart per acre although, in exceptional circumstances, 1.5 quarts may be used. Wolfson Rebuttal Rpt. at 7-8. Because the Plan Colombia spraying applied 4.45 quarts of Roundup Ultra per acre, Dr. Wolfson concludes that 3 to 4.5 times the recommended amount of glyphosate was applied through the Plan Colombia aerial spraying. Id. at 8. However, Dr. Wolfson bases his conclusion on an excerpt of the label and, without explanation, ignores the surrounding sections of the label. The full label states, in relevant part: "Unless otherwise specified, do not exceed 1 quart of [Roundup Ultra] per acre.... Refer to the individual use area sections of this label for recommended volumes, application rates and further instructions." Pls.' Opp'n to DynCorp's Mot. for Summ. J. Based on Lack of Necessary Expert Test., Ex. 4 (Michael Wolfson Expert Rebuttal Rpt., Ex. A at 2). In his deposition, Dr. Wolfson implied that he referred to the individual use area sections of the label and "found what [he] believe[d] to be the maximum concentration recommended anywhere on the label[.]" Wolfson Dep. at 58:11-17. But he admitted that the label "is so complex and detailed" that he may have missed the appropriate section listing the maximum concentration of Roundup Ultra that may be used in the Plan Colombia context. Id. The defendants presented evidence that Dr. Wolfson indeed did miss the appropriate section. They offer expert testimony by Dr. Joseph
Second, Dr. Wolfson again relies on the Roundup Ultra label for his opinion that the Plan Colombia herbicide contains excessive amounts of surfactant. The Roundup Ultra label states that surfactant should not be added to a spray solution when Roundup Ultra herbicide is the only pesticide used. Wolfson Rpt. at 3. Dr. Wolfson reasoned that because "[t]he coca spray mixture apparently contains Roundup Ultra as the only pesticide/herbicide in the solution[,]" "the coca spray mixture used by Plan Colombia, fails to follow [the] manufacturer's label directions for the use of [Roundup Ultra]" since it added the surfactant Cosmo-Flux 411F. Id. But Dr. Wolfson admitted that he had not explored the significance of the instruction and did not know whether the statement regarding adding surfactant was required by the Environmental Protection Agency for safe use or was optional. Wolfson Dep. at 50:7-10. Moreover, Dr. Wolfson could not say whether Dr. DiTomaso was correct that the instruction was included on the label for business reasons rather than reasons of safety. Id. at 50:11-18; see also DiTomaso Rpt. at 202 (stating that "manufacturers often include statements [such as those regarding adding surfactant to Roundup Ultra] in the product labeling... to remind the user that Roundup formulations already include a surfactant and to suggest (subtly or not) that it is unnecessary to purchase additional surfactants and additives (from other chemical manufacturers) to effectively control weeds and other undesired plants"). Dr. Wolfson also conceded that he did not know whether, despite the label, surfactants are routinely added to Roundup Ultra. Wolfson Dep. at 49:20-23. Thus, Dr. Wolfson's testimony is based not on scientific knowledge but on subjective belief and unsupported speculation that the directions he cited from the manufacturer's label are requirements for safe use of Roundup Ultra and should have been followed by the defendants in the Plan Colombia operation. The plaintiffs, then, have not demonstrated that Dr. Wolfson's testimony regarding the excessive concentration of surfactant in the Plan Colombia herbicide would be reliable.
The defendants assert that "`[s]imply having a medical degree or training is insufficient expertise to establish causation.'" Defs.' Mot. at 9 (quoting Cunningham v. Masterwear, Inc., No. 1:04-cv-1616-JDT-WTL, 2007 WL 1164832, at *10 (S.D.Ind. Apr. 19, 2007)). They continue that Dr. Wolfson is not qualified as an expert to testify as to specific or general causation because "he is not an expert in epidemiology or toxicology, the two fields of expertise relevant to the question whether the Plan Colombia herbicide could cause the test plaintiffs' alleged acute injuries or alleged increased risk of cancer." Id. at 9. The plaintiffs counter that being a toxicologist or epidemiologist is not required to be qualified to offer expert testimony on causation and Dr. Wolfson's experience qualifies him as an expert. Pls.' Opp'n at 6.
Although the D.C. Circuit has not spoken on the qualifications necessary to offer
In Morin v. United States, 534 F.Supp.2d 1179 (D.Nev.2005), the plaintiff alleged that regular exposure to jet fuel from a military air station caused her to develop a malignant brain tumor. Id. at 1181. The plaintiff's only proffered expert to testify as to causation was a practicing physician who regularly diagnosed and treated patients with cancer. Id. at 1185. As in Cunningham, the court in Morin distinguished between the expert's experience diagnosing and treating the underlying ailment and his experience determining the cause of the ailment, and held that the licensed oncologist was not qualified to testify as to the causal link between jet fuel and brain tumors because he had "no expertise in toxicology, epidemiology, risk-assessment, or environmental medicine." Id. The guidance that emerges from these cases is that an expert is qualified to testify as to causation in a toxic tort case when he has expertise to "assess [a disease's] genesis to a reasonable degree of scientific certainty." Sutera v. Perrier Grp. of Am. Inc., 986 F.Supp. 655, 667 (D.Mass.1997).
This guidance mirrors approaches used in this district. For example, the court in Dyson considered whether a witness who was not a physician could offer expert testimony that a drug given to a pregnant patient had caused birth defects. 113 F.Supp.2d at 50. As happened in Cunningham and Morin, the court looked past the witness's professional title and formal education and considered whether the proffered expert had experience identifying the effect of chemical exposure during pregnancy. Id.
In his expert report, Dr. Wolfson describes his lengthy career in occupational and environmental medicine. Dr. Wolfson also states that he has "rendered thousands of diagnoses and opinions on the causation of disease involving complex issues of toxic exposures" and, through his clinical practice, conducted "environmental and occupational risk assessment and toxic exposure evaluations[.]" Wolfson Rpt. at 1-2. Dr. Wolfson's resume supports his statements. Thus, although Dr. Wolfson does not have any formal education in epidemiology or toxicology, his expert report supports a finding that he has vast experience in environmental medicine, conducting risk assessments, and assessing the genesis of diseases caused by toxins. As such, the plaintiffs have made an ample showing of Dr. Wolfson's qualifications as an expert to offer causation testimony.
In a toxic tort case, general causation requires that the plaintiff "show
In toxic tort cases, there are two common methods experts apply to draw causation conclusions. First, an expert may rely on "a temporal relationship between exposure to the toxin and subsequent adverse health effects" to establish both general and specific causation. See Young, 567 F.Supp.2d at 128. In compelling circumstances, a temporal relationship between exposure to a toxin and a plaintiff's injury alone is sufficient to establish general causation. See Cavallo v. Star Enterprise, 892 F.Supp. 756, 773-74 (E.D.Va.1995), aff'd in relevant part, rev'd in part, 100 F.3d 1150 (4th Cir.1996). For example, a temporal relationship may be "so compelling as to dispense with the need for reliance on standard methods of toxicology" where a person is exposed to a large amount of chemical X and "immediately thereafter developed symptom Y[.]" Id. Also, if a chemical is introduced into an environment and all of the people "exposed immediately develop the same adverse reaction, then the episode itself may be sufficiently indicative of causation." Id. However, "[i]n the absence of an established scientific connection between exposure and illness, or compelling circumstances ..., the temporal connection between exposure to chemicals and an onset of symptoms, standing alone, is entitled to little weight in determining causation." Moore v. Ashland Chem. Inc., 151 F.3d 269, 278 (5th Cir.1998); see also Young, 567 F.Supp.2d at 128. This is because "[d]rawing such a conclusion from temporal relationships leads to the blunder of the post hoc ergo propter hoc fallacy."
An expert may also rely on a temporal relationship between the exposure to a toxin and onset of symptoms to form a specific causation opinion. For example, in Westberry v. Gislaved Gummi AB, 178 F.3d 257, 265 (4th Cir.1999), the court of appeals allowed expert testimony that relied in part on the temporal proximity between exposure to the toxin in the plaintiff's workplace and the plaintiff's injury. In Westberry, there was no dispute that inhalation of high levels of the toxin at issue could cause sinus conditions similar to those suffered by the plaintiff and there was evidence that the plaintiff had been substantially exposed to the toxin. Id. The plaintiff's proffered expert was the plaintiff's treating physician, the plaintiff's injury began shortly after exposure to the toxin, and the expert had "experimented with keeping [the plaintiff] out of work and noticed that his sinus condition improved when he was not working but worsened when he returned." Id. at 265; cf. Roche
The second common expert method used to establish general and specific causation is to "present scientifically-accepted information about the dose-response curve for the toxin which confirms that the toxin can cause the health effects experienced by the plaintiff at the dosage [the] plaintiff was exposed to." Young, 567 F.Supp.2d at 128. If an expert uses this methodology, "`scientific knowledge of the harmful level of exposure to a chemical, plus knowledge that the plaintiff was exposed to such quantities, are minimal facts necessary to sustain the plaintiff's burden in a toxic tort case.'" Id. (quoting Mitchell v. Gencorp Inc., 165 F.3d 778, 781 (10th Cir.1999) (citing Wright v. Willamette Indus., Inc., 91 F.3d 1105, 1106 (8th Cir.1996))). This is the "most widely-used method" to demonstrate causation in toxic tort cases. Id. As such, "[t]he expert who avoids or neglects this principle of toxic torts without justification casts suspicion on the reliability of his methodology." McClain, 401 F.3d at 1241-42.
Dr. Wolfson admitted that he could not opine as to "the dose and duration of exposure to Plan Colombia herbicide spray that will be required to cause any one of the medical conditions for which the plaintiffs complain[.]" Wolfson Dep. at 210:20-25.
The defendants argue that Dr. Wolfson's general causation opinion is unreliable because it is based on "`studies of patients who try to commit suicide' by directly ingesting large amounts of the concentrated Roundup product." Defs.' Mot. at 19 (quoting Wolfson Dep. at 124:20-25). The plaintiffs counter that it was reliable for Dr. Wolfson to base his opinion on high-level exposure studies. Pls.' Opp'n at 15-16. Drawing inferences and extrapolating from studies of high-level exposure to a toxin is not a per se unreliable methodology. See, e.g., City of Greenville v. W.R. Grace & Co., 827 F.2d 975, 980 & n. 2 (4th Cir.1987). However, it does require that the expert explain his methodology, such as how he "extrapolate[d]
In his deposition, Dr. Wolfson testified that the suicide studies were only "part of the basis for [his] opinion" and that he "integrated the information about the signs and symptoms of disease from those studies in a whole body of evidence that's available about the effects" of glyphosate-based herbicides. Wolfson Dep. at 124:11-25. In their opposition, the plaintiffs also stated that Dr. Wolfson did not rely "exclusively" on studies of suicide attempts and data sheets regarding exposure by ingestion to form the basis of his general causation opinion. Pls.' Opp'n at 15-16. Despite their representation that Dr. Wolfson relied on other studies, the only alternative methodology offered by the plaintiffs is that Dr. Wolfson "evaluated relevant peer-reviewed scientific and medical literature including, but not limited to, material regarding toxicological, environmental, and human health effects of herbicides, Glyphosate (G), Roundup and surfactants." Id. at 7-8; see also Wolfson Rpt. at 2.
Rather than identifying the specific scientific reports that Dr. Wolfson relied on to reach his general causation opinion, the plaintiffs make only generic references to reports that support Dr. Wolfson's general causation opinion. Similarly, Dr. Wolfson's expert report and expert rebuttal report do not specifically identify the reports that support Dr. Wolfson's general causation opinions and do not discuss the conclusions the reports and texts reached. Such a generalized and non-specific description falls short of the plaintiffs' burden to explain with specificity the expert witness's methodology, show that the expert's testimony is based on a reliable methodology, and establish that the expert reliably applied the methodology to the facts of the case. See Fed.R.Evid. 702. Moreover, Dr. Wolfson did not base his opinion on any peer-reviewed study that states that exposure to a glyphosate-based herbicide through drift can cause any of the medical conditions complained of by the test plaintiffs in this case. Wolson Dep. at 141:21 to 142:2. Furthermore, some of the studies Dr. Wolfson cites in his expert
Dr. Wolfson states in his expert report that "[t]he exposure of the plaintiffs to [the Plan Colombia] herbicide[], as a result of aerial spraying, very likely places them at a significant increased risk for the development of cancers in the future." Wolfson Rpt. at 3. Although the plaintiffs' "description" of Dr. Wolfson's methodology suffers from many of the same shortcomings as his general causation opinion for the plaintiffs' acute injuries, Dr. Wolfson does specifically identify a few peer-reviewed studies to support his conclusion that glyphosate-based herbicides have carcinogenic effects. See Wolfson Rebuttal Rpt. at 3 & nn. 3-4; Wolfson Dep. at 400:15-21.
However, a brief review of the cited studies demonstrates that the plaintiffs have not shown that Dr. Wolfson's testimony is reliable. For example, the plaintiffs fail to reveal how, based on the studies alone, Dr. Wolfson reached the conclusion that exposure to the Plan Colombia herbicide increased the plaintiffs' risks for developing non-Hodgkins lymphoma. Dr. Wolfson cites several studies including studies by Eriksson, et al., Hardell and Eriksson, and De Roos, et al. Eriksson and his colleagues conducted a population-based control study and concluded that "Glyphosate was associated with a statistically significant increased [odds ratio] for lymphoma[.]" Mikael Eriksson et al., Pesticide exposure as risk factor for non-Hodgkin lymphoma including histopathological subgroup analysis, 123 Int'l J. Cancer 1657, 1662 (2008). The Hardell
The plaintiffs do not explain Dr. Wolfson's methodology for his specific causation opinion regarding the plaintiffs' chronic injuries and his methodology cannot be gleaned from his expert report or rebuttal report. Because the plaintiffs have not met their burden to show that Dr. Wolfson's testimony on specific causation regarding the plaintiffs' chronic injuries is reliable, this testimony will be excluded.
Dr. Wolfson opines that a medical "monitoring regime is necessary and indicated for an exposed ... group[] of individuals such as [the] plaintiffs, within a reasonable degree of medical certainty" because the plaintiffs are at an increased risk for significant adverse health effects in the future. Wolfson Rpt. at 4. The plaintiffs suggest that Dr. Wolfson's education and experiences qualify him as an expert. Pls.' Opp'n at 5-6. However, the plaintiffs offer no further explanation as to how Dr. Wolfson's education qualifies him to offer such testimony or how his experience caused him to reach his conclusion. Conclusory statements that an expert is qualified because of his education or experience is insufficient for a court to find that the witness is indeed qualified to offer his expert opinion. See DL, 730 F.Supp.2d at 81. Similarly, neither the plaintiffs nor Dr. Wolfson offer any explanation or evidence regarding the reliability of Dr. Wolfson's methodology. Because the plaintiffs have not met their burden to show that Dr. Wolfson is qualified and that his testimony is reliable, Dr. Wolfson's medical monitoring testimony is inadmissible.
"The court shall grant summary judgment if the movant shows that there is no genuine dispute as to any material fact and the movant is entitled to judgment as a matter of law." Fed.R.Civ.P. 56(a). The Memorandum Opinion entered on February 7, 2013 determined that the plaintiffs must offer expert testimony to prove general causation for the plaintiffs' acute and chronic injuries, and specific causation for
The plaintiffs failed to show by a preponderance of the evidence that Dr. Wolfson's expert opinion testimony on the proper mixture and application rate of the Plan Colombia herbicide, general causation regarding the plaintiffs' acute and chronic injuries, specific causation regarding the plaintiffs' chronic injuries, and need for medical monitoring is admissible. However, Dr. Wolfson's specific causation opinion regarding the plaintiffs' acute injuries is not excludable. Thus, the defendants' motion to exclude Dr. Wolfson's expert testimony will be granted in part and denied in part. Without the plaintiffs' sole expert witness's general causation opinions regarding the plaintiffs' acute and chronic injuries and his specific causation opinion regarding the plaintiffs' chronic injuries, the plaintiffs cannot establish causation as a matter of law, and summary judgment will be entered for the defendants. A final Order accompanies this Memorandum Opinion.
Reed v. Philip Morris Inc., No. 96-5070, 1997 WL 538921, at *16 n. 10 (D.C.Super. Aug. 18, 1997) (internal quotation marks omitted). Dr. Wolfson's testimony that the defendants did not follow the directions on the Roundup label and his causation opinions are relevant to the plaintiffs' negligence claims — the breach of duty and causation elements, respectively. Dr. Wolfson's causation testimony is also relevant to the plaintiffs' medical monitoring claims as is his medical monitoring opinion.
