Plaintiff’s lawyer grills defense toxicologist in Monsanto trial

SAN FRANCISCO -- Plaintiff's attorney Brent Wisner sparred with Monsanto Co.'s expert toxicologist Thursday over the credibility of his testimony as well as conclusions drawn by the Environmental Protection Agency over the company's weed killers potentially causing cancer.

In a contentious cross-examination of Warren Foster, Wisner accused Monsanto scientists of steering the Environmental Protection Agency to incorrectly interpret certain studies, which led to the toxicologists concluding glyphosate is not an animal carcinogen.

The questioning focused largely on the significance and implications of key studies presented by the defense.

Kirby Griffis, a partner with Hollingsworth LLP, started direct questioning by clarifying that Foster conducted his own independent analysis of glyphosate carcinogenicity in animal studies and asked what he concluded from his review.

"My bottom line conclusion is that glyphosate doesn't induce long-term tumors in animals," he said.

Foster next discussed the role of chance in interpreting certain data results as statistically significant instead of being a false positive.

There would undoubtedly be tumors which are false positive but are interpreted as being statistically significant because of the sheer volume of test subjects in the animal studies, according to the toxicologist.

He also claimed another potential flaw in the studies finding glyphosate to be an animal carcinogen is that "rodents are not tiny people" and that one simply cannot "generalize results from mice to humans."

"In my view, the plaintiff's experts have misapplied and overinterpreted the statistical data," Foster said. "They relied primarily upon statistical comparisons without giving due considerations to the changes taking place in these animals."

The plaintiff's lawyer, however, said an EPA science advisory board criticized the agency for erroneously throwing out data results, which he said was done at the urging of Monsanto scientists.

"So the scientific advisory panel was very critical of this part," Wisner said, pointing to data results the agency is alleged to have erroneously thrown away after urging by Monsanto scientists, according to plaintiff's attorneys. "[That's not the] proper approach in a carcinogenicity study, right?"

Foster, certified as an expert on toxicology and the evaluation of carcinogenicity in animal studies, agreed.

"And you literally threw the results away in front of the jury, right?" Wisner asked, referring to Foster testifying that he did not incorporate certain study results to conclude that glyphosate is not an animal carcinogen.

"Because I determined there was ... a lack of statistical significance," Foster said. "There were many reasons, not just one. ... It's the weight of it all and not just one thing."

"And you weighed it after Monsanto hired you, right?" Wisner said.

"The way you're characterizing that is the only reason I did that is because I'm an expert witness to Monsanto," Foster said. "I take exception to that because as a scientist, the only thing I have is my lack of bias."

"So it'd be fair to say that the EPA didn't follow guidelines," Wisner said.

"I did my independent assessment," Foster said. "It happens to agree with the EPA's conclusions, but the conclusion's the same."

Plaintiff Dewayne Johnson alleges product liability and negligence, among other claims, and seeks roughly $2.25 million in compensatory damages. Legal observers expect plaintiff's attorneys to request roughly $40 million in punitive damages.

This is the first of more than 4,000 cases nationally to take the agrochemical company to trial on allegations that its glyphosate-based weed killers cause non-Hodgkin lymphoma. Johnson v. Monsanto Co. et al., CGC-16-550128 (S.F. Super. Ct., filed Jan. 28, 2016).

San Francisco County Superior Court Judge Suzanne Bolanos is still undecided on jury instructions concerning punitive damages.

The trial continues Friday.