EAST ST. LOUIS - After an expert witness for plaintiffs claiming weed killer paraquat caused Parkinson's disease testified to attributing nearly 75% of the weight of his causation opinion on one study, the plaintiffs explain a shortage of research by accusing manufacturer Syngenta of corrupting science in general and the U.S. Environmental Protection Agency (EPA) in particular.
During the final two days of a hearing in the paraquat litigation in August, plaintiff counsel Eric Kennedy of Cleveland said, “I don't know of another case where a defendant has such an impact on the literature.”
The plaintiffs await a decision from Chief U.S. District Judge Nancy Rosenstengel on a motion to bar Jack Housenger's testimony, who worked 40 years for EPA. They challenged his testimony during the hearing, saying he would essentially be a surrogate for the agency.
Plaintiff counsel Kahldoun Baghdadi of San Francisco asked, “How could he somehow bring to this courtroom what an agency that is not here and will not be here was thinking?”
He said if Rosentengel allows his testimony, she should allow plaintiffs to provide context.
“We need to be able to provide the jury with context of how the EPA gets to where it did and we need to be able to provide the jury with context of what Syngenta did and which employees of Syngenta ended up at the EPA and which former employees at the EPA ended up at Syngenta,” he said.
Rosenstengel presides over about 4,600 suits against Syngenta and Chevron from district courts in many states by appointment of a judicial panel in Washington, D.C.
She first heard a full day of testimony from plaintiff expert Martin Wells on Aug. 22.
He reviewed seven studies, assigned 74% weight to one from 1997, and found a higher odds ratio for association between paraquat and Parkinson’s disease than any of the studies found. His primary study was conducted more than a decade after Chevron ended its paraquat business.
He excluded larger and more recent studies from his review.
The next day, Chevron counsel Sharyl Reisman of New York City told Rosenstengel, “He reached opinions first and then found and retrofitted a methodology to it later.”
Reisman said Wells created an unreliable methodology after the fact to reach a predetermined result.
“The point is not that old studies are by definition low quality. The point is that you can't leave the game at halftime and pretend to know the final score,” she said.
She asked why the National Institutes for Health would spend millions on studies with no merit.
Kennedy said Wells analyzed case control studies.
“Dr. Wells' opinion is you do not combine case control studies with cohort studies in a single meta analysis,” he said.
“When two studies overlap in their data, you cannot put both of them into a meta analysis. That would be double counting,” he added.
“You don't want garbage in your meta analysis because then your summary odds ratio will be garbage,” he continued.
The examination was then turned over to plaintiff Sara Peters of San Francisco.
Rosenstengel told her that Reisman attacked the reliability of how Wells chose his studies.
“Was it systematic? Could it be replicated?” she asked.
Peters said the inquiry was whether a sound methodology followed established principles.
Rosenstengel said to Kennedy, “Defendants argue that Dr. Wells is dispositive of the case.”
“If I decide Dr. Wells is out, then at least these four trial pick cases are gone,” she said.
Rosenstengel asked if he had an alternative, and Kennedy said, “At the current moment, no.”
“With respect to these four plaintiffs, without Dr. Wells' foundation of general causation, the odds ratio over two which we utilize for specific causation, that would be dispositive of these cases,” he said.
Rosenstengel said if she lets Wells testify, she’d limit his opinions to occupational exposure and diagnosis of Parkinson's disease.
“Anything that doesn't check those boxes, even if I let Dr. Wells in, has a problem,” she said.
Motions to exclude experts
Lang and Shah
Rosenstengel then heard arguments on a defense motion to exclude causation opinions of neurologists Anthony Lang and Binit Shah.
Syngenta counsel Brad Weidenhammer of Chicago said they based their opinions entirely on assumptions that counsel provided to them.
He said neither doctor used this methodology before, and the causation theory behind the assumptions contradicted the scientific consensus.
He added that Lang published hundreds of papers on Parkinson's disease and never published one concluding that paraquat causes it.
"They made no attempt to reconcile these assumptions with the many review articles finding evidence is insufficient to prove causation,” he said.
Weidenhammer said they didn't attempt to reconcile the assumptions with Lang's own repeated conclusions that genetics are the only known cause of the disease.
He said neither doctor offered any opinion or analysis on whether assumptions they were told to make were actually reliable or valid.
“In order to accept these assumptions, they had to ignore real world science,” he said.
Weidenhammer said they didn’t take into account risks for any factor other than paraquat.
He added that Shah admitted that many factors might have contributed to development of Parkinson's in one of the trial plaintiffs and admitted that he didn't ask about other risks aside from family history.
“You must analyze an individual's constellation of potential risk factors and causes and you've got to compare that with the study populations that generated this odds ratio that you're considering applying to these individuals,” he said.
“You've got to do it before you apply it to the individuals. Otherwise it's invalid,” he added.
Plaintiff counsel David Landever of Cleveland said there was no evidence that Lang set aside his expertise as plaintiffs instructed.
“It was not only appropriate for Dr. Lang and Dr. Shah to rely upon the opinions of other professionals with differing expertise. It was required,” he said.
Landever said plaintiffs presented evidence that Lang didn’t know until recently, including a study analyzed by Syngenta showing paraquat could remain in the brains of monkeys for months.
“Neither is acting as a mouthpiece. They are simply assuming that opinion,” he said.
Rosenstengel asked if Lang and Shah reviewed the studies before Wells analyzed them.
Landever responded, “Dr. Wells was given an assumption. He told us the studies that he was planning to look at in his evaluation. We gave them to Dr. Lang. We gave them to Dr. Shah.”
“We said you need to look at these studies to determine whether the diagnostic criteria are sufficiently reliable and sufficiently uniform that these studies could be combined in a meta analysis to produce a reliable odds ratio. Dr. Lang did that,” he said.
“The timing of these expert declarations were all simultaneous, so we picked up the phone and we said 'Dr. Wells, you are to assume that the diagnostic criteria in these seven studies that you have chosen have sufficiently reliable and sufficiently uniform criteria to allow for their meta analysis,'” he added.
Olanow
The next day, Rosenstengel heard a motion of plaintiffs to bar neurologist Warren Olanow.
He had asserted that no published review or panel of experts concluded that paraquat is a cause of Parkinson’s disease or contributes to its cause.
Baghdadi said Syngenta scientists identified what they couldn’t tell the public, that paraquat enters the brain and causes changes.
“Rules were issued in 2008. Don't do any research on paraquat without having the research proposal first approved by Syngenta's legal department,” he said.
“Syngenta wanted to make sure that its scientists didn't go down avenues of research that would expose truths about paraquat that were counter to the claims of safety,” he added.
“To say that there is either an inconsistency in the literature or that there is a paucity of research in the literature, it's worth noting and worth emphasizing that very few Defendants can impact literature the way Syngenta has and does,” he continued.
Baghdadi said Chevron stopped publishing when they got out of the business in 1986.
Weidenhammer said that for decades Olanow was the most cited Parkinson's researcher in the United States.
“Scientists all over the country and over decades have done multiple reviews of the literature concerning paraquat and Parkinson's disease,” he said.
“Not a single one of those reviews has concluded anything different than Dr. Olanow,” he added.
“Animal studies use doses of paraquat that are thousands or even tens of thousands of times higher than those measured under ordinary working conditions in applying paraquat,” he continued.
Housenger
Plaintiffs then challenged Housenger.
Baghdadi said the Earth Justice group petitioned EPA to reconsider its interim decision that no research has identified paraquat as a cause of Parkinson's disease.
Rosenstengel asked what evidence the group had.
Baghdadi said, “By citing to the scientific evidence in the literature that is out there shows an association with Parkinson's and being critical of the EPA in the evaluation that they did in terms of following the steps that they did.”
He said the petition is online and plaintiffs cited it in their papers.
“We do not object that the jury is told that paraquat was registered with the EPA,” he said. “We do not object that the jury's told that the EPA regulates pesticides or herbicides or that the EPA went through a registration review.”
“In other words, there is no claim here that paraquat was sold without the necessary agency or regulatory foundation to do so,” he added.
“Where we cross from explanation to advocacy is just where Mr. Housenger is,” he continued.
Syngenta counsel Ragan Naresh of Chicago said EPA comprehensively regulated paraquat for 50 years.
“EPA dictates the safety tests that need to be conducted, the kinds of conditions of use for using paraquat in the fields, and selling paraquat, and who it can be sold to,” he said. “EPA dictates what goes on the label, not just the words and the substance of the label but all the way down to font size and color.”
“Jurors are going to ask themselves, if the plaintiffs are right, why can paraquat be sold here? Does EPA just ignore this, falling asleep on the job?” he added.
“EPA hasn't fallen asleep. EPA has specifically considered the question of whether the evidence supports a claim that paraquat causes Parkinson's disease and the plaintiffs are seeking to keep that answer from the jury,” he continued.
Naresh said Baghdadi argued that EPA effectively admitted its interim decision was unreliable.
He added that EPA explained that it confessed no error in the interim decision, which is in place until EPA or a court says otherwise.
Spencer
Syngenta counsel Steven Geise of San Diego argued for a motion to exclude testimony of plaintiff expert Peter Spencer.
Spencer stated defendants knew enough in the 70s to undertake testing on primates.
Geise said Spencer looked for any evidence of neurotoxic effects, transported himself back in time, and asked himself what he would have done with that evidence at that time.
He said Spencer stated in a deposition that if he expressed an opinion, it was certainly to a degree of probability exceeding 51%.
Spencer was asked if the standard for a scientist reaching a conclusion was 51% or greater than that; and he answered, “In the context of this deposition and in the context of my report, I'm discussing more probable than not with a 51 percent plus or greater standard of certainty.”
Spencer added, “When I submit a paper for publication that says that X causes Y, I would have a much higher standard because I know that the reviewer would trash the report and I would not be published and I would also develop a very bad reputation."
Geise said Spencer's conclusion was different in this case than conclusions in his textbooks.
“It's because he uses a lower standard that lacks the scientific rigor and integrity that he used when he made these publications,” he said.
“He goes back in time. He said he put himself in the mid-70s and asked himself what would he have done with the information at that time,” he added.
“No other person can put themselves back in time and predict what somebody else did. It's not capable of replication,” he continued.
Geise said the difference between what Spencer said in litigation and what he said in the real world was a sign of how unreliable his methodology was.
Peters responded to the 51% comment, saying the question was about the scientific standard for a causation opinion in a peer reviewed journal versus preponderance of evidence.
Rosenstengel asked, “Are you aware of any authority that says that it's acceptable for an expert to apply a civil preponderance standard for an opinion given in court if that standard has no application in the scientific work?”
Peters quoted a Ninth Circuit decision that a court wrongly conflated standards for publication with standards for admitting expert testimony.
She also quoted a Seventh Circuit case that an expert must apply the same rigor as in his professional work and must be equally as careful.
“The standard for reasonable conduct is what was required of them in light of what they knew and they should have taken these next steps which would have eventually led them to take it off the market when they confirm what we know today from the epidemiology,” she said.
Rosenstengel asked, “Is there any peer reviewed scientific publication that has found a causal relationship between paraquat and Parkinson's?
Kennedy said, “Movement Disorders Journal.”
Reisman responded, “Movement Disorders Journal was entirely based on a journalist’s piece, so it’s not a review.”
She said it refers to a book where there was a causal association paragraph.
She added that it was all about pesticides and didn’t cite a single paraquat study.
“The chapter cites two studies or three studies on paraquat and just mentions it as something under investigation and some findings have been made,” she said.
Reisman said the paragraph about causation didn’t even reference the prior paragraph.
“I'm happy to provide the Court with the book. We have extra copies,” she said.
Rosenstengel asked, “It was all pesticides?”
“It was all pesticides,” Reisman responded.