Plaintiff experts who testify that even extremely low levels of asbestos exposure can cause cancer may be in trouble after a study of some 2 million women found no difference between urban and rural residents in the rate of mesothelioma, a deadly cancer of the chest lining that is normally associated with asbestos.
The study in the journal Risk Analysis found rural mesothelioma rates actually exceeded urban rates in more than half of the years studied between 1973 and 2012, despite the fact ambient asbestos exposures in urban areas are an order of magnitude higher due to heavy use of asbestos in commercial construction until the 1970s.
The results appear incompatible with the idea that exposure to even a tiny amount of asbestos, such as the trace amounts plaintiff lawyers claim are in talcum powder, can cause mesothelioma. Unless urban women use dramatically less talcum powder than their rural counterparts, they would be expected to have higher rates of mesothelioma given their daily exposure to 10 times as much ambient asbestos. The implications of the article were so serious that one plaintiff expert wrote a letter to the journal to question its findings, prompting the study’s authors to pen a highly critical response.
The study also found female mesothelioma rates remained essentially unchanged over the study period, in contrast to male mesothelioma rates, which more than tripled between 1973 and 1992 before declining again as the population of men exposed to high occupational levels of asbestos shrank. Mesothelioma typically takes several decades to manifest itself and has been found to be closely associated with industrial exposure to the most dangerous amphibole fibers used as high-temperature insulation in ships and factories.
The flat mesothelioma rates for women – who held comparatively few such industrial jobs over the same period – are consistent with research suggesting many cases of mesothelioma have no connection to asbestos.
The study is likely to be cited by defense lawyers as they seek to disqualify plaintiff experts who are prepared to testify that small exposures to asbestos can cause mesothelioma, said Oded Burger, an associate with Goldberg Segalla in New York. To prove liability in a tort case, plaintiffs must show asbestos was a “substantial factor” in the chain of causation.
“It pulls the rug out from under the argument that just because a level of exposure is above background, that that fact has any sort of meaning in terms of the sufficiency of the exposure to cause disease,” Burger said.
For plaintiff lawyers, each diagnosis of mesothelioma now represents hundreds of thousands of dollars in potential legal fees as they negotiate settlements with an ever-growing list of defendant companies, ranging from huge manufacturers like Ford Motor Co. to individual hardware stores and plumbing supply houses. It was the quest for such fees that drove Sheldon Silver, once the most powerful legislator in New York, to cut a deal with a mesothelioma physician to obtain the names of newly diagnosed patients that he sold to Weitz & Luxenberg, a prominent plaintiff law firm, in exchange for more than $3 million in fees. Silver was convicted of bribery in May.
Asbestos plaintiffs rely on expert testimony to stay in court, however. And nowhere is that testimony more critical than in the talcum powder cases, where experts must be prepared to explain how a daily dusting of baby powder can cause a cancer that most epidemiological studies associate with much higher industrial exposures.
Talcum powder manufacturers like Johnson & Johnson dispute there are any asbestos fibers in their products, but plaintiff lawyers – sometimes using samples they bought on eBay – claim their experts have found stray fibers. Attorney Mark Lanier won a $4.69 billion verdict against Johnson & Johnson earlier this year in part by showing jurors a drawing depicting “Johnson’s Baby Powder” as the factor pushing a woman with multiple potential sources of ovarian cancer off a cliff.
Plaintiff lawyers are sure to point out the article in Risk Analysis was authored by Meghan E. Glynn and colleagues at Cardno ChemRisk, a consulting firm that works with defense lawyers. Co-author Jennifer Sahmel was an expert for Colgate-Palmolive in a California talc case that ended with a defense victory in 2016.
But the peer-reviewed study was conducted entirely with National Cancer Institute data and doesn’t challenge the broader theory that high levels of amphibole asbestos exposure can cause mesothelioma. It only undermines the idea that lower levels can be blamed, since if that were true, urban residents would be expected to have much higher rates of cancer.
In a letter to Risk Analysis, Murray Martin Finkelstein, a family medicine doctor at the University of Toronto who serves as a plaintiff expert in mesothelioma cases, said the authors “did not take account of asbestos exposures arising from body and baby powders.” Using plaintiff estimates of the amount of asbestos in baby powder, he said a person using “shaker and puff application” of baby powder in a small bathroom would be exposed to 1 asbestos fiber per cubic centimeter of air per day, equal to a cumulative annual exposure several times the level of ambient exposure.
Finkelstein also cited research by Dr. Victor Roggli of Duke University that found talc fibers in the lungs of 65% of mesothelioma patients and more common in women than in men. He used that to dispute the authors’ conclusion that the 10-fold difference in ambient asbestos levels between urban and rural women didn’t influence mesothelioma rates, since both groups of women presumably used baby powder.
In an unusual response to Finkelstein’s letter, the study’s authors said he relied on questionable research financed by plaintiff lawyers to conclude there are any asbestos fibers in baby powder. Other studies found no such contamination, they said, even in samples used by the plaintiff expert.
They also questioned Finkelstein’s comparison of the potential exposure to a single daily dusting of baby powder to the 24-hour-a-day inhalation of asbestos fibers every human is exposed to. Finally, they said they contacted Roggli of Duke University, who “indicated that Dr. Finkelstein had misrepresented the results” of his research. It is unclear what point he was trying to make with the research anyway, they said: Finkelstein gave only the levels of talc found in the lungs of mesothelioma patients with no reference to the amounts in healthy individuals.
“The relatively constant rates of female pleural mesothelioma over time in both urban and rural areas suggests that neither ambient background asbestos concentrations, nor theoretical asbestos exposures from contaminated cosmetic talc products (if any), have collectively or individually influenced the risk of pleural mesothelioma among females in the United States,” the authors concluded.
Finkelstein, in an e-mailed comment, said he had “no idea what they mean” by misrepresentation of the Roggli data, because he used the raw data from the Duke researcher’s database.
The first wave of asbestos litigation targeted companies like Johns-Manville that produced the most dangerous types of amphibole asbestos insulation. After most of them were driven into bankruptcy the lawyers moved on to manufacturers of products containing other forms of asbestos, which epidemiological studies have shown are much less dangerous, as well as companies that used, transported or stored asbestos-containing products.
They have succeeded in court with theories that even low-level exposures such as from brake pads can cause cancer, despite numerous studies showing no excess rates of cancer for car mechanics. Now lawyers are targeting small businesses like hardware stores with lawsuits, as well as filing thousands of cases against talcum powder manufacturers. The talc litigation may solve the demographic problem illustrated by the study’s finding of flat mesothelioma rates for women over the past several decades. If that is truly the background rate of mesothelioma in the population, the lawyers need a theory to explain where it’s coming from absent occupational exposure – and a defendant company to blame.