and, in turn, delayed regulations governing their use,” the University of California at San Francisco authors wrote. “PFAS are now ubiquitous in the population and environment.”
The study used scientific methodology previously developed by tobacco industry researcher Stan Glantz to analyze similar documents from cigarette makers. The authors found PFAS producers and their allies most frequently employed two tobacco strategies: withholding internal studies that revealed health risks and distorting public discourse.
DuPont’s chief toxicologist in 1961 found rats’ livers enlarged at very low doses of exposure, a health impact recognized as “the most sensitive sign of toxicity.” The report recommended PFAS be handled “with extreme care” and that “contact with the skin should be strictly avoided.” In the early 1980s, DuPont found elevated liver enzymes in 60% of workers tested, and a confidential internal report detailed birth defects among pregnant plant employees. In the years that followed, 3M and DuPont internal studies found the chemicals likely caused prostate, testicular, bladder and kidney cancers.