PFAS: The EPA Updates Interim Drinking Water Advisories
June 21st, 2022
Today the EPA published adjusted interim PFAS drinking water Health Advisory levels for PFOA and PFOS from 70 ppt (ng/L) combined to 0.004 ppt for PFOA, 0.02 for PFOS, 10 ppt for Gen X, and 2,000 ppt for PFBS (the Gen X and PFBS Health Advisory levels were new). The EPA’s Health Advisory can be seen here and press release here (the press release may eventually be taken down, and has already been edited between the time I post this and the time I first read it… as far as I can tell they removed the values from the press release). The prior values were set in 2016.
Health advisories are defined in the document as such: “Health advisories describe concentrations of drinking water contaminants at which adverse health effects are not anticipated to occur over specific exposure durations (e.g., one-day, ten-days, and a lifetime). Health advisories serve as technical information to assist Federal, state and local officials, as well as managers of public or community water systems in protecting public health. They are not regulations and should not be construed as legally enforceable Federal standards. Health advisories may change as new information becomes available.”
These are interim values and will be reviewed by the EPA Science Advisory Board, which is made of members from both the public and private sector. After input from the Science Advisory Board, the EPA will create Maximum Contamination Level Goals. These are also non-enforceable values used to support eventual regulation the EPA is shooting for in the fall of 2022.
My thoughts:
One of the points EPA make in the new release is when considering PFAS exposure on a lifetime scale, any exposure could contribute to possible negative health effects. Many PFAS have very long biological half-lives (5 years + for some), so any exposure can be a long ordeal. And, along with that, its very difficult to understand and pin down what health risks could be associated with exposures. I think this point is valid. I look forward to reading the justification given for the final regulatory levels later this year.
The part that perplexes me is how low these values are. The EPA’s current methods (Method 533 and Method 537.1) for analyzing drinking water (or any other reasonable method that I know of for that matter) cannot detect PFOS and PFOA at these purposed levels. In fact, their lowest concentration minimum reporting level for these methods are several orders of magnitude higher than the interim values meaning that our current techniques are nowhere near adequate enough measure how low these Health Advisory levels are. I would be surprised if any body of water on the planet has PFOS and PFOA concentrations this low, not that you could even find that out. Although, the EPA does state this issue with detection limits in their press release, so maybe there is some aspects of this I don’t know about yet.
To give perspective on just how low these concentrations are. The interim drinking water Health Advisories are the equivalent of 1 drop in 1,000 swimming pools for PFOS and 1 drop in 5,000 swimming pools for PFOA using this metric.
Image taken from Michigan.gov.
Final thought. Previous PFAS drinking water values have been calculated on the assumptions that most of the average American’s PFAS exposure will be through drinking water. Most of my publication history (and a couple that are coming down the pipe) has been focused a large potential PFAS exposure source in food. I’ve presented this information at several conferences, as a seminar to the EPA itself, and have spoken to the FDA and state governments on the matter. In the EPA’s press release, they state “EPA’s lifetime health advisories also take into account other potential sources of exposure to these PFAS beyond drinking water (for example, food, air, consumer products, etc.), which provides an additional layer of protection.” I would like to believe that maybe the reduction in these drinking water PFAS Health Advisory levels could be making room for greater factoring in of PFAS exposure through food. But, of course I would hope that, it would validate several years of my life.
Learn more about PFAS with our other posts:
Our Publications on PFAS:
Plant Uptake of Per- and Polyfluoroalkyl Acids under a Maximum Bioavailability Scenario
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