Surprisingly, some of the most convincing studies indicating the dangers of PFAS come from 3M themselves[1][2]. These studies were of course never intended for public release:
> In 1961, company lab tests linked C8 exposure to enlarged livers in rats and rabbits. DuPont scientists then conducted tests on humans, asking a group of volunteers to smoke cigarettes laced with C8. “Nine out of 10 people in the highest-dosed group were noticeably ill for an average of nine hours with flu-like symptoms that included chills, backache, fever and coughing,” the researchers noted. “Concerns about the potential toxicity of C8 had been raised internally within DuPont by at least 1954, leading DuPont’s own researchers to conclude by at least 1961 that C8 was toxic and, according to DuPont’s own Toxicology Section Chief, should be ‘handled with extreme care,'” Bartlett’s February 2013 suit against DuPont alleged.
> In one study, for instance, Olsen looked at blood tests of 3M employees at the company’s plants in Antwerp, Belgium, and Decatur, Alabama, both of which made PFOA and PFOS, among other products. By the late 1990s when Olsen was embarking on this research, these chemicals were known within the company to accumulate in humans and alter cholesterol levels in lab animals. Because the workers had undergone three separate rounds of blood tests, Olsen was able to trace the levels of the chemicals in workers’ blood over time. And by combining his results with various clinical measures the company had been tracking in its workers, he was able to see whether there was a relationship between the chemical and these health outcomes. Olsen’s findings, written up in an draft report in October 2001, were clear. There was a positive association between the amount of PFOA in workers’ blood and their levels of cholesterol and triglycerides, states the report, on which Olsen is listed as the principal investigator.
They've also taken some... drastic measures regarding which factory workers are allowed to be exposed to certain PFAS despite publicly denying any connection with birth defects[3]:
> In a November 1982 memo, DuPont's chief medical director, Dr. Bruce Karrh, expressed concern over employee exposure to C8. The company then barred women of child-bearing age from working around C8.
Far be it from me to condemn an abundance of caution, but the timing seems odd when you consider what happened a year prior[3]:
> When Bailey returned to work in 1981, she discovered a memo on a bench in the women's locker room. It detailed a study by 3M, which sold C8 to DuPont, that detailed eye deformities in lab animals whose mothers were fed C8 during pregnancy. Bailey went to the plant's medical doctor and asked if this is what happened to [her child born with an eye deformity]. The doctor denied a connection, according to Bailey, but arranged an appointment at Johns Hopkins University Hospital in Baltimore.
> DuPont scientists then conducted tests on humans, asking a group of volunteers to smoke cigarettes laced with C8.
This is definitely not my area, but ... was this a good experiment to do? I don't just mean from an ethical standpoint (though that seems super sketch), but purely as an experiment to understand how this chemical impacts the human body, this seems not great?
(a) if you smoke a cigarette, isn't the actual dose of C8 taken in by each subject likely to be both variable and hard to measure? Different subject would have just exhaled vs absorbed different amounts of C8, right? So it seems like you get a less precise dosing than most other means of getting it into the body?
(b) couldn't this have been toxic in the lungs in a way which wouldn't have been relevant to other/more typical means of exposure? Does reacting badly to something inhaled as smoke really imply anything about the impact of touching or ingesting it? I'm pretty sure e.g. that cayenne smoke would cause you problems that touching or eating that same substance would not cause.
> In 1961, company lab tests linked C8 exposure to enlarged livers in rats and rabbits. DuPont scientists then conducted tests on humans, asking a group of volunteers to smoke cigarettes laced with C8. “Nine out of 10 people in the highest-dosed group were noticeably ill for an average of nine hours with flu-like symptoms that included chills, backache, fever and coughing,” the researchers noted. “Concerns about the potential toxicity of C8 had been raised internally within DuPont by at least 1954, leading DuPont’s own researchers to conclude by at least 1961 that C8 was toxic and, according to DuPont’s own Toxicology Section Chief, should be ‘handled with extreme care,'” Bartlett’s February 2013 suit against DuPont alleged.
> In one study, for instance, Olsen looked at blood tests of 3M employees at the company’s plants in Antwerp, Belgium, and Decatur, Alabama, both of which made PFOA and PFOS, among other products. By the late 1990s when Olsen was embarking on this research, these chemicals were known within the company to accumulate in humans and alter cholesterol levels in lab animals. Because the workers had undergone three separate rounds of blood tests, Olsen was able to trace the levels of the chemicals in workers’ blood over time. And by combining his results with various clinical measures the company had been tracking in its workers, he was able to see whether there was a relationship between the chemical and these health outcomes. Olsen’s findings, written up in an draft report in October 2001, were clear. There was a positive association between the amount of PFOA in workers’ blood and their levels of cholesterol and triglycerides, states the report, on which Olsen is listed as the principal investigator.
They've also taken some... drastic measures regarding which factory workers are allowed to be exposed to certain PFAS despite publicly denying any connection with birth defects[3]:
> In a November 1982 memo, DuPont's chief medical director, Dr. Bruce Karrh, expressed concern over employee exposure to C8. The company then barred women of child-bearing age from working around C8.
Far be it from me to condemn an abundance of caution, but the timing seems odd when you consider what happened a year prior[3]:
> When Bailey returned to work in 1981, she discovered a memo on a bench in the women's locker room. It detailed a study by 3M, which sold C8 to DuPont, that detailed eye deformities in lab animals whose mothers were fed C8 during pregnancy. Bailey went to the plant's medical doctor and asked if this is what happened to [her child born with an eye deformity]. The doctor denied a connection, according to Bailey, but arranged an appointment at Johns Hopkins University Hospital in Baltimore.
[1]: https://theintercept.com/2018/07/31/3m-pfas-minnesota-pfoa-p... [2]: https://www.ecowatch.com/teflons-toxic-legacy-dupont-knew-fo... [3]: https://www.delawareonline.com/story/news/2016/04/02/c8-susp...