ONE new analysis Among previously undisclosed industry documents by academic researchers in the United States seem to confirm that chemical companies have known for more than 60 years about the health hazards of exposure. with per- and polyfluoroalkyl substances (PFAS) discharges from their facilities, but have been actively working to prevent knowledge.
PFAS is a widely used chemical that exists in the environment and bioaccumulates in humans and animals, occurring in water systems and ecosystems around the globe. They have also been linked with a variety of health problems.
A team led by Nadia Gaber at the University of California, San Francisco (UCSF) comprehensively reviewed a collection of previously unpublished documents held by DuPont and 3M, the largest PFAS producer. These documents, dating from 1961, were discovered during litigation and subsequently donated to UCSF’s. Chemical Industry Document Library.
‘Internal studies have identified, between 1961 and 1994, that DuPont has evidence of PFAS toxicity from internal animal and occupational studies that it does not publish in the scientific literature. and do not report their findings to EPA [US Environmental Protection Agency]’ as required by the US Toxic Substances Control Act, the team explained in the paper. ‘All of these documents were marked as ‘confidential’ and in some cases industry executives have made it clear that they ‘want this memo destroyed’.’
In some cases, industry executives have made it clear that they “want this memorandum to be rescinded.”
The analysis found that although PFAS were considered biologically inactive until about 2000, the chemical industry had many studies showing adverse health effects at least 21 years before they were released. reported in the public results. One of the earliest studies identified is from 1959 – it examined potential respiratory and skin toxicity from the production of new plastics, including polytetrafluoroethylene, and noted that the cases ‘tonn’ flu-like effects’ have been reported in the occupational literature and are attributed to smoking. compound contamination.
In addition, a 1961 report by DuPont chief technician found hepatomegaly in rats exposed to C8 (perfluorooctanoic acid, PFOA), which was found in the company’s previous Teflon non-stick products. when it is replaced by GenX (dimer oxide hexafluoropropylene acid and its ammonium salt). In addition, DuPont and 3M apparently learned in 1980 that two of the eight pregnant employees working in the C8 manufacturing plant had given birth to babies with birth defects, but the company did not disclose it. find out or tell the staff about it. Furthermore, the following year, an internal memo stated, ‘We know of no evidence of birth defects caused by C8 at DuPont.’
‘We are the first scientists to analyze these internal industry documents to show how PFAS manufacturers hide the health effects of their products,’ Gaber said. Chemistry world. The researchers created a timeline that compared the published literature with private industry research and found that the manufacturers were known or suspected of the hazards, she added. seriously in public for at least two decades.
The veil of secrecy
‘The documents show that even when companies suspect their chemicals are harmful to their own employees, they continue to withhold and downplay that information,’ Gaber continued. ‘To do so, they used many of the strategies of the tobacco and pharmaceutical industries.’
These materials would greatly benefit public health if they were made available, according to Scott Belcher from the PFAS Center for Health and Environmental Impacts at North Carolina State University in Raleigh, USA.
“Sometimes the veil of secrecy about business information really makes public health assessments difficult,” he said. chemistry world. “If there are known toxicity at the scale this seems to reflect, it could potentially be of great service to public health if substitutes were found,” says Belcher. for these chemicals. ‘We can’t make the right decisions without the data.’
historical responsibility
DuPont declined to comment on the UCSF report’s statements. However, a spokesman for the company, Daniel Turner, said it involved ‘historic’ issues. He pointed out that DuPont spun off its chemical businesses, including fluoro products, in 2015, forming Chemours. The company’s 2017 merger with Dow Chemical to form DowDuPont, and later split into separate agrochemicals (Corteva), materials (Dow) and specialty products companies, meant that the company The company now known as DuPont de Nemours has never produced perfluorooctanoic acid, perfluorooctane sulfonic acid or He suggested firefighting foams containing PFAS.
Turner asserts: “The assignment of DuPont de Nemours to previous issues ignores the company’s development process as well as the shifting of existing product lines and personnel with complete companies. totally different.
When asked for comment, a Chemours representative said the report “is not about Chemours” and that the company “will not comment on matters involving other companies”.
3M responded only to say that it had “resolved many of the false features of these documents in a previous report”.
