forever chemical (PFAS)

Introduction

perfluoroalkyl & polyfluoroalkyl substances (PFAS)

• estimated > 12,000 perfluoroalkyl & polyfluoroalkyl substances

Uses

• PFAS repel oil, repel water, resist heat, & reduce friction
• nonstick cookware
• water-resistant & stain-resistant fabrics
• cosmetics, dental floss, cleaning products, food packaging
• fire-extinguishing foam

Epidemiology

• no natural breakdown, thus forever
• PFAS are found in air, soil, fish, & water sources
• found in drinking water & manufactured products
  • drinking rainwater is unsafe
  • levels of PFAS in rainwater often exceed US Environmental Protection Agency Lifetime Drinking Water Health Advisory levels
• occupations with high levels of PFAS exposure include electroplating, firefighting, carpet installation & treatment, food & hospitality industry (food packaging for takeout orders often contains PFAS)
• microwave popcorn, waterproofing sprays, & stain-resistant carpeting often contain PFAS
• CDC has detected PFAS in serum samples of almost everyone tested since 1999
• perfluorooctanoic acid (PFOA), then used to make DuPont de Nemours Teflon nonstick coating contaminated drinking water in the early 2000s
• perfluorooctanesulfonic acid (PFOS) is another PFAS with previous widespread use
• tapwater in nearly half of U.S. water supply contains PFAS

Adverse effects

• PFOA exposure linked to hypercholesterolemia, kidney cancer, testicular cancer, thyroid disease, ulcerative colitis, & pregnancy-induced hypertension
• PFAS (chiefly PFOA or PFOS) also linked to breast cancer
• suppression of vaccine immune response in children

Management

• PFAS can be destroyed by temperatures > 374 C
• patients with a history of high exposure to PFAS should be tested for PFAS
  • regular monitoring & screening as indicated
• patients with PFAS serum levels 2-20 ng/mL should receive routine lipid panels screening for breast cancer
• if PFAS serum levels > 20 ng/mL, physicians should try to identify the source
• patients > 15 years should be assessed for testicular cancer & ulcerative colitis
• patients > 18 years should have thyroid function testing
• patients> 45 years should have urinalysis & assessment for kidney cancer
• filter drinking water with activated carbon or reverse osmosis filters to mitigate PFAS consumption

Notes

• PFAS have remained largely unregulated by the US Environmental Protection Agency (EPA), but this could be changing
  • in 2021, the EPA released a road map to address harmful PFAS
  • in 2016, PFOA and PFOSset the threshold for PFOA & PFOS in drinking water to 70 parts per trillion
  • in June 2022, the EPA changed the threshold to 0.004 parts per trillion for PFOA & 0.02 for PFOS, suggesting that there are no safe levels of detectable traces of PFAS in drinking water