Introduction
On June 22, 2023, 3M finally agreed to pay a settlement ranging from a minimum of $10.5 billion to a maximum of $12.5 billion. According to the agreement, 3M will provide funds to U.S. public water systems over the next 13 years for testing and treating PFAS contamination. Although 3M has reached this settlement agreement, they refuse to admit liability for the pollution.
PFAS
PFAS, per- and polyfluoroalkyl substances, possess extremely difficult-to-break carbon-fluorine single bonds (C-F bonds), making them resistant to photolysis, hydrolysis, biodegradation, or metabolism by animals. The environmental half-life of PFAS (the time required for degradation to half its original amount) can be as long as a century, whereas the half-life of the radioactive element tritium in Fukushima's nuclear wastewater is only 12.43 years. This gives PFAS an almost indestructible property. Scott Belcher, an associate professor of biological sciences at North Carolina State University, said, "Once they're here, they're not going away." PFAS is a vast group of chemical substances, with over 5,000 common chemicals. Due to their water-resistant, grease-resistant, friction-reducing, and high thermal stability characteristics, they are widely used in various industrial manufacturing processes and are ubiquitous in daily life. According to a 2022 study in Environmental Science and Technology, clouds absorb PFAS from water evaporated from contaminated oceans, which then falls to the ground with rainfall. "Every drop of rain has PFAS," Belcher said. "That was really shocking news to me." On May 19, TIME magazine published an article titled "All The Stuff in Your Home That Might Contain PFAS 'Forever Chemicals'," and the result was—PFAS is everywhere. Clothing, furniture, pizza boxes, food packaging, cookware, electronics (phone and computer screens), fire extinguishers (firefighting foam), shoes, contact lenses, shampoo, dental floss, toilet paper, and more.
The most direct way for humans to ingest PFAS is through tap water.
The U.S. Environmental Protection Agency estimates that 70 to 94 million Americans have drinking water contaminated with PFAS. Other researchers from the Environmental Working Group believe the actual number is much higher—over 200 million.
How toxic is PFAS? Science is still studying it. As a typical endocrine disruptor, PFAS not only poses health risks even at extremely low levels of exposure but also varies depending on individual constitutions, making so-called safe levels difficult to predict. Once PFAS is absorbed by the human body, it first binds to serum proteins and then deposits in various organs such as the liver, kidneys, and testes, where it cannot be excreted.
It can even increase the risk of thyroid disease, high cholesterol and hypertension, diabetes and chronic liver disease, as well as certain types of cancer, such as kidney and testicular cancer. On February 17, researchers from Harvard University and the National University of Singapore published a study in the journal Science of the Total Environment, finding that permanent chemicals (PFAS) in women's cosmetics may reduce female fertility by up to about 40%.
On June 1 this year, a team of professors from the University of California, San Francisco (UCSF) published an article in the Annals of Global Health, claiming that they analyzed internal documents from the largest PFAS manufacturers—DuPont and 3M. These documents revealed that they were aware of the hazards but concealed and delayed government regulation for decades. During World War II, the United States carried out the development of the atomic bomb (the Manhattan Project). In the process, a chemist passed the toxic yellow-green gas fluorine through a carbon arc, creating an almost indestructible compound—PFAS. Subsequently, 3M purchased this patent at a high price and applied it to petrochemicals, electrical appliances, construction, and other civilian fields.
It wasn't until 1975, when over 200 cattle died on a farm next to a waste dump, that farmer Erl Tenant dissected the dead cattle and preserved the infected organs as evidence, bringing the hazards of PFAS to public attention.
Original text from National Geographic Chinese website, no link provided.