What's in your waterproofs?
Posted by Gerard on November 18, 2022, 12:57 pm
"If you're reading this, chances are great you've got PFCs in your blood. |
Since the 1940s, industrial quantities of perfluorinated chemicals (PFCs), have been manufactured and sold by various chemical companies, most notably 3M and DuPont, for use in well-known products like Scotchguard and Teflon.
There are thousands of variations on the chemistry, which is essential to making consumer products resistant to stains, grease and water. Aerospace, automotive, building and construction and the electronics industries also rely on PFCs for their ability to reduce friction in the manufacturing process.
Because of their ubiquity in cookware, carpet, textiles, upholstery, mattresses, food packaging and firefighting foams, almost all Americans have been exposed to and accumulated some volume of PFCs in their body.
One PFC, perfluorooctanoic acid (PFOA), was found in blood serum in 99 percent of the U.S. general population between 1999 and 2012.
A perfluorooctanesulfonic acid (PFOS) molecule.
The chemistry: Perfluorinated chemicals, also called polyfluoroalkyl substances (PFASs) or polyfluorinated compounds, feature a carbon backbone with fluorine atoms attached each bonding point. Other chemicals like hydrogen, oxygen and chlorine can attach to the end of the carbon chain. Varying the chain length, attached flourines and other atoms can produce different PFCs. For example, PFOA has 8 carbons in its chain and is sometimes referred to as C8.
The toxicity: Perfluorinated chemicals are very stable under harsh conditions, which makes them a great tool for spraying on liquid jet fuel fires but a terrible thing for the environment and the human body. Their stability allows PFCs to persist in the ground and water and bio-accumulate in fish and wildlife. As with mercury, smaller concentrations magnify up the food chain until they land in the diet of fish-eating humans, where the PFCs can remain in the body for years.
The effects: In laboratory studies on animals, some PFCs are shown to disrupt normal endocrine activity, reduce immune system functions, have adverse effects on organs like the kidneys, liver and pancreas. The U.S. Environmental Protection Agency links two PFCs, PFOS and PFOA, to thyroid disorders and childhood developmental issues. Exposure over certain levels to unborn children or breastfed infants may cause complications like low birth weight, accelerated puberty and skeletal variations. The chemicals have also been linked to testicular and kidney cancers, liver damage and cholesterol changes.
Why isn't this more widely known? Perfluorinated chemicals haven't quite broken into mainstream consciousness the way other poisons have. That's because there's still a huge amount of study yet to be done. Today, PFCs are considered "emerging contaminants" and are not subject to enforceable regulation or cleanup standards in the U.S. -- although the EPA this spring published health advisory guidelines for PFOS and PFOA that suggest prolonged exposure over 70 parts-per-billion (ppt) can cause health problems. There's ongoing government and university study of other PFCs, but PFOS and PFOA have been scrutinized the longest and therefore the government is comfortable quantifying the risk. The U.S. and Canadian governments also just listed PFOS and PFOA as chemicals of "mutual concern." Unfortunately, it takes years of study to develop enough data on toxicity for agencies like the EPA to enact regulations. Also, because there are so many PFC variants, scientists are having trouble assessing the risk potential across the entire chemical class.
Where are PFCs found in Michigan? In Michigan, concern about PFCs began elevating in 2010, when testing found PFOS at never-before-seen levels in fish at Clark's Marsh in Oscoda. Plumes from the closed Wurtsmith Air Force Base, which used a firefighting foam loaded with PFCs, contaminated the wetland and PFCs are still being found at elevated levels in local wells. Elsewhere, PFOS and PFOA have been found in raw and treated water in Ann Arbor and Plainfield Township water supplies. Surface water testing has found PFCs in the AuSable River, Flint River, Kalamazoo River, Saginaw River and St. Joseph River. A 2015 Michigan Department of Health and Human Services report noted that "future source investigations should focus on locations where PFOS-based-firefighting foam may have been used in large quantities and on sources in urban centers."
PFC problem beyond Michigan: The PFC plumes at Wurtsmith helped wake the U.S. Air Force up to contamination at other military bases. Today, the military is cleaning up PFC-contaminated drinking water near active or former bases in Delaware, Alaska, Pennsylvania, California, New Hampshire, New York, Ohio, Virginia, New Jersey and Colorado. That's just a sampling. Military officials have upped the number of possible contaminated sites to 2,000. Industrial use of PFCs in chemical or plastic-making has polluted communities like Hoosick Falls, N.Y., Bennington, Vt., Parkersburg, W. Va., and Washington, W. Va.
What can you do? Experts say PFCs cannot be boiled out of water, but can be removed by reverse osmosis filters, which can cost several hundred dollars for a good model. Michigan is buying filters for folks with contaminated wells in Oscoda and there's $1 million in the new budget to hook people up to safe, municipal water. That's only necessary, however, if you're drinking contaminated water. Because certain PFCs have been phased-out of manufactured products, newer domestically-made items should reduce some latent exposure. You can further reduce PFC exposure by ditching non-stick cookware, or using non-metal utensils with Teflon-coated pans. Also, consumers can choose furniture and carpets not marketed as "stain resistant," avoid grease-repellant food packaging like French fry boxes, microwave popcorn and pizza boxes, and avoid consumer products with ingredients listing "fluoro" or "perfluoro.""