Per- and polyfluoroalkyl substances or PFAS—a group of persistent toxic chemicals often referred to as “forever chemicals”—are everywhere. Don’t take my word for it. Here is a list posted on the site of the U.S. Environmental Protection (EPA) agency:

  • Food packaged in PFAS-containing materials, processed with equipment that used PFAS, or grown in PFAS-contaminated soil or water.
  • Commercial household products, including stain- and water-repellent fabrics, nonstick products (e.g., Teflon), polishes, waxes, paints, cleaning products, and fire-fighting foams (a major source of groundwater contamination at airports and military bases where firefighting training occurs).
  • Workplace, including production facilities or industries (e.g., chrome plating, electronics manufacturing or oil recovery) that use PFAS.
  • Drinking water, typically localized and associated with a specific facility (e.g., manufacturer, landfill, wastewater treatment plant, firefighter training facility).
  • Living organisms, including fish, animals and humans, where PFAS have the ability to build up and persist over time

PFAS are even found in animals in Antarctica. Here is a list of health effects again provided by the EPA:

  • Infant birth weights
  • Effects on the immune system
  • Cancer (for PFOA)
  • Thyroid hormone disruption (for PFOS).

PFOA and PFOS are specific kinds of PFAS. Perhaps of most interest right now because of the ongoing pandemic are the deleterious effects of these chemicals on the immune system including reducing the effectiveness of vaccines. And, perhaps the most important thing you need to know about PFAS is that scientists keep reducing their estimates of what is a safe exposure as more data accumulates.

PFAS have been around since the 1950s. So, how did these dangerous chemicals—which don’t break down in the environment—escape the notice of regulatory officials for so long? The answer is all too familiar and echoes similar trajectories for such toxic legacies as unleaded gasoline, glyphosate, chlorofluorocarbons, and bisphenol A.

A 2018 piece by a renown public health researcher in Environmental Health details the long and sordid history of repression of scientific knowledge about PFAS and a dangerous irony about the way we assess risk from such substances.

Let me highlight just a few of his main points:

  • The assumption that untested chemicals are safe, a guiding principle in law even today, particularly in the United States, is simply not logical.
  • Industry studies on the health affects of PFAS were first referenced in the scientific literature in 1980. But those studies were kept from the public and the government for another 20 years.
  • By 2000 the presence of PFAS in samples from blood banks was well-known.
  • Until relatively recently, the industry research and the growing independent research findings since 2000 have been largely ignored by regulatory officials.
  • A study revealing the negative effects of occupational exposure on the immune systems of men was never published by the industry because it could not agree with the author on how to change the wording [presumably to water down the conclusions]. The study is only coming out now because it was discovered in the course of litigation.
  • In the last 10 years independent evaluation of PFAS has revealed the broad extent of its damaging effects.
  • Even so, the EPA has yet to announce regulatory limits on exposures to PFAS.

Also mentioned in the article linked above is an irony that stands out above all others in the history of PFAS research. Testing revealing the negative effect of these chemicals on human response to vaccines was disregarded at the time because the researchers were unable to recruit a control group. In this case, the control group would be formed from individuals NOT exposed to these chemicals to make sure that effects showing up in the experimental group, that is, the group exposed to the chemicals, are, in fact, due to those chemicals and not some other factor in the environment. But, of course, it was impossible to form a control group because practically everyone on the planet has PFAS circulating in their bodies.

This preference for experimental results significantly impeded acceptance of the dangers of PFAS even though the ever-increasing epidemiological data was signaling those dangers.

We must circle back now to the assumption that untested chemicals should be presumed safe. The chemical industry has been creating substitutes for the now identified troublesome members of the PFAS family as those chemicals are phased out. But, it turns out that the replacements are from the same family of chemicals and may have effects just as bad or worse than what they replaced.

Maybe we should have tested those replacements carefully BEFORE they came to market. But that’s considered “crazy talk” by the industry and by most of the politicians who could pass laws that might require such pre-market testing for the potential health and environmental effects of all new chemicals (and belated testing for all the ones that were never tested).


P.S.   After finishing my piece, I discovered this article which covers just released research suggesting that PFAS contamination in drinking water is much more widespread across the United States than previously believed.

Photo: Old Chemicals in Natural History & Science Museum. Lisbon (2014) Photo by xlibber via Wikimedia Commons