66 Volume 85 • Number 3 YOUR ASSOCIATION The smothering heat index of 107 on Thursday, July 21, 2022, visibly produced copious sweat in most of the pedestrians and casually dressed tourists. The day oozed moisture, honoring the sweltering sauna reputation that Washington, DC, is renowned for. I had anticipated the humidity but did not forecast the sobering discussion that left me overheated by its implications. I exited the co ee shop and plunged into the late afternoon sun, fully charged by the animated dialogue and double espresso. My ca einated beverage partner was Dr. Rebecca Aicher, project director of the Center for Scientific Evidence in Public Issues (EPI Center) within the American Association for the Advancement of Science (AAAS). AAAS is an international association of 120,000 members dedicated to advancing science, engineering, and innovation. You might recognize them for a variety of reasons but perhaps most visible are their publications— the Science family of journals. The mission of the EPI Center is to deliver clear, concise, and actionable scientific evidence to policy makers and other decision makers. The EPI Center makes it easier for policy makers and others to access relevant scientific evidence and then integrate that evidence into their decision-making process. Dr. Aicher and I discussed developments centered on per- and polyfluoroalkyl substances—known as PFAS to many of us. PFAS were introduced and widely used in the 1960s and continue to be ubiquitous in commercial applications. These chemicals are long lasting with half-lives ranging from 4–5 years. In other words, some public health scientists characterize them as forever chemicals because once you have been exposed, you will likely have the residuals in your body for the balance of your life. These chemicals possess admirable properties and are beneficial for their nonstick and grease-, oil-, and water-resistant qualities. In that context they have many useful applications: grease-resistant fast-food wrappers. nonstick cookware, stain-resistant coatings on carpets, and water-resistant clothing (think of all that camping gear), among many other products. The U.S. Environmental Protection Agency (U.S. EPA) PFAS website indicates that there are over 9,000 individual chemicals in the PFAS family. These chemicals accumulate in the ecosystem and subsequently bioaccumulate into human tissues over time, potentially leading to adverse health conditions including many that we fear most—cancer and birth defects. Additionally, the Agency for Toxic Substances and Disease Registry research involving humans suggests that elevated levels of certain PFAS chemicals may give rise to increased cholesterol levels, decreased vaccine response in children, increased risk of high blood pressure or preeclampsia in pregnant individuals, and increased risk of kidney or testicular cancer. U.S. EPA reports that PFAS and its sibling chemicals have been discovered in drinking water systems throughout the globe. Regretfully, that is just the beginning. Many processed foods, including organic products, have detectable PFAS levels. Research into biosolids (i.e., sewage sludge) shows evidence of PFAS contamination, with implications for tens of millions of acres of agriculture that have historically been sprayed with this product. U.S. EPA released four drinking water health advisories for PFAS on June 15, 2022. The health advisories identify the concentration of chemicals in drinking water at or below which adverse health e ects are not anticipated to occur: 0.004 ppt for perfluorooctanoic acid (PFOA) and 0.02 ppt for perfluorooctanesulfonic acid (PFOS)—both are members of the PFAS family. Think about it: 1 ppt is a single drop in 18 million gallons of water. Please note that health advisories are nonregulatory and reflect an assessment by U.S. EPA of the best available peer-reviewed science. The PFAS saga is not new. We hosted a hill briefing for Congress in November 2019 with speakers from the Centers for Disease Control and Prevention, Association of Public Health Laboratories, and National Association of County and City Health O¡cials. We convened the program in a large room David Dyjack, DrPH, CIH Seersucker Thursday Di recTalk continued on page 65 We should be the chief science o cers of our communities.