I saw an interesting paper about PFAS published last August and wanted to write about my thoughts. In a comprehensive study of tap water by the United States Geological Survey (USGS) containing 716 sites, it was found that 45% of tap water locations in the U.S. contain PFAS. The three most common PFAS found were PFBS, PFHxS, and PFOA.
Something that stood out to me immediately was the presence of PFBS, PFHxS, and PFOA in 15% of the samples. PFBS and PFHxS are what are known as short-chain PFASs, which I’ve talked about in previous blog posts. In short, these chemicals were introduced by chemical companies like DuPont to dodge regulatory suspicion from the government. However, these chemicals have also demonstrated the potential to cause the same negative health effects associated with long-chain PFAS. To me, the presence of short-chain PFAS in drinking water supplies indicates that not enough is likely being done to control PFAS pollution. Short-chain PFAS have only been an alternative to long-chain PFAS for about 15 years, but they have already begun to replace long-chain PFAS in the environment.
The differences in specific PFAS between water sources are also intriguing to me. About a year ago, I sent a sample of tap water from my own house to a certified lab for liquid chromatography-mass spectrometry (LC-MS) testing. The only detected PFAS was PFOA, which was present at 1.9ng/L. This experience really made me understand how much of a nightmare it is for the EPA to figure out a national standard for PFAS, especially when water sources across the U.S. can contain so great a variety of PFAS that may not all cause the same negative health effects. Based on these conclusions, I think that it’ll definitely be a while before we see enforceable national limits on PFAS.
Sources
USGS Paper