3M’s Cordova chemical plant on the Mississippi River
Health Matters
By Jeffrey Kluger TIME
IN 2023, IT’S HARD TO GET AWAY from breaking news about PFAS, a class of more than 12,000 chemicals used in countless products from nonstick pans to cosmetics to food packaging. These so-called forever chemicals have been linked to a host of physical ills, including increased risk of certain cancers, high cholesterol, hormonal disruption, immune-system problems, decreased fertility, and developmental delays in children.
PFAS, first developed in the 1940s, weren’t always so well known by people outside of the industries manufacturing them. But a new study analyzing industry documents published in Annals of Global Health reveals just how much and how early the two biggest manufacturers of the chemicals— 3M and DuPont—knew about the potential harms the products posed. As the researchers found, 3M and DuPont had preliminary evidence of PFAS toxicity as early as the 1960s, and knew broadly about the dangers the chemicals pose by 1970—two decades before the public really became aware of the chemicals’ health risks.
The study also reveals that the tactics the companies used to cover up what they knew about the toxicity of PFAS—suppressing unfavorable research, distorting public disclosure of research that did leak out, withholding information from employees who might have been exposed to dangerous levels of PFAS—are reminiscent of those used by the tobacco and fossil-fuel industries.
“Having access to these documents allows us to see what the manufacturers knew and when, but also how polluting industries keep critical public health information private,” said Dr. Nadia Gaber, an emergency-medicine resident and the first author of the paper, in a statement. “This research is important to inform policy and move us towards a precautionary rather than a reactionary principle of chemical regulation.”
In an email to TIME, DuPont said, in part, “In 2019, DuPont de Nemours was established as a new multi-industrial specialty products company. DuPont de Nemours has never manufactured PFOA or PFOS [two types of PFAS]. DuPont de Nemours cannot comment on allegations contained in the UCSF paper that relate to historical . . . matters.” 3M emailed a comment as well, stating, “The paper is largely comprised of previously published documents—as evidenced by the paper’s references section, which includes citations dating back as far as 1962. 3M has previously addressed many of the mischaracterizations of these documents in previous reporting.”
THE SECRETS BEGIN
It was in 1961 that the dissembling around the dangers of PFAS started, according to the study. That year the Canadian Medical Association Journal published a report of workers in PFAS factories who fell ill after smoking cigarettes that had been contaminated with PFAS-based Teflon. Shortly after, an account surfaced of a worker on a U.S. Air Force base who somehow came into possession of a similarly contaminated cigarette, smoked it, and died on site. DuPont and the Air Force dismissed the account as a rumor—and the author of the original Canadian paper, apparently bowing to industry and military pressure, posted a retraction, saying in part, “all rumors of death are false.”
But the researchers say DuPont knew better. In 1961, a DuPont study found Teflon exposure led to liver enlargement in rats, with the in-house scientist recommending “contact with the skin should be strictly avoided.” In 1962 a company scientist conceded internally that Teflon may be reactive to excessive heat and handling. And in 1970, researchers at a West Virginia DuPont plant found PFAS chemicals could be “highly toxic when inhaled and moderately toxic when ingested.” None of these findings were made public.
Among the human studies the companies conducted, researchers found “a possible increase in prostate cancers” had been reported among employees at one manufacturing plant. Other findings showed elevated liver enzymes in 61% of 30 workers tested, indicating inflammation and damage to cells in the liver.
WORKING THE PUBLIC
As the evidence of the dangers mounted, the authors say, 3M and DuPont began covering up what they knew. In 1991, researchers unaffiliated with the companies began detecting PFAS in groundwater. The companies responded with a joint press release stating that internal studies showed the chemicals had “no known toxic or ill health effects in humans at concentration levels detected.” In 2000, health officials in Lubeck, W.Va., detected several forms of PFAS in drinking water. In response, DuPont assured the officials that all was well. The officials repeated the company line, stating, “DuPont reports that it has toxicological and epidemiological data to support confidence that exposure guidelines established by DuPont are protective of human health.”
But by now, the genie was out of the bottle. Researchers unaffiliated with the companies were publishing more and more studies on the risks of PFAS, linking it to increased risk of certain cancers and other ills; one lawsuit had already been adjudicated, and a second case was coming. And in 2000, 3M even announced it would no longer be manufacturing the PFAS-based fabric-protecting Scotchgard.
Last year, the EPA set permissible levels for PFOA and PFOS in drinking water, and it is working to do the same with six more types by 2026. Public demand is leading to a growing market for PFAS-free products, leaving companies like DuPont and 3M either to abandon—or at least curb—the chemicals or get left behind. As for the companies’ reputations, studies like the just-released one might make for a difficult cleanup job there too.