PFAS in Recreational Water: The Pool Problem
Swimming pools represent an often-overlooked PFAS exposure pathway. Research published in Environmental Science & Technology Letters in 2020 found PFAS in water samples from public swimming pools at concentrations of 10–200 ng/L—significantly elevated above typical municipal drinking water concentrations at the time. PFAS enter pool water from multiple sources: swimmer personal care products (sunscreens, cosmetics, hair products containing PFAS); PFAS-treated swimwear releasing fluorotelomer compounds during use; pool chemical formulations containing PFAS surfactants; and source water containing background PFAS. The warm, chlorinated pool environment and extended bather contact (dermal absorption, incidental ingestion, inhalation of volatilized compounds) creates a distinctive PFAS exposure profile distinct from drinking water exposure.
Research Findings on Pool Water PFAS
A 2020 study from the University of Bath analyzed 24 public swimming pools in the UK, finding PFAS in all sampled pools. Concentrations ranged from 17 to 7,100 ng/L for total PFAS—with indoor competitive pools showing higher concentrations than outdoor leisure pools, likely due to less dilution from fresh water input and higher bather loads. PFOS was detected in 92% of pools; PFHxS in 83%; PFOA in 75%. The study calculated that swimmers participating in intensive training (2+ hours daily, 5 days/week) receive PFAS body doses from pool water potentially comparable to drinking water exposure at concentrations near current MCLs. Research from Duke University (2022) confirmed similar findings in US indoor public pools, with concentrations in heated competitive pools exceeding 500 ng/L for some PFAS compounds.
Sources of Pool PFAS: Swimmers as Contributors
Contrary to initial assumptions that source water was the primary pool PFAS contributor, research suggests that bathers themselves are the dominant PFAS loading source through: sunscreen products containing PFAS film formers (fluorotelomer acrylate copolymers); waterproof mascara and foundation with fluoropolymer ingredients; PFAS-treated swimwear releasing fluorotelomer compounds at pool temperatures; and sweat and urine (which contain PFAS from personal background body burden). Studies found that pools using non-PFAS source water (private wells without PFAS) still accumulated PFAS to concentrations comparable to pools using municipal water with detectable PFAS—confirming bather contributions as a primary pathway. This finding has implications for pool management: encouraging PFAS-free personal care product use before swimming could reduce pool PFAS concentrations.
Regulatory Gap and Future Directions
No jurisdiction currently regulates PFAS specifically in recreational water. The UK’s Pool Water Treatment Advisory Group (PWTAG) and the US Model Aquatic Health Code (MAHC) do not address PFAS. WHO’s guidelines for safe recreational water environments do not include PFAS parameters. However, the research trajectory is clear: as PFAS measurement in recreational water becomes more routine and health impact assessments are completed, recreational water PFAS will enter the regulatory agenda—potentially triggering requirements for source water treatment, pool chemistry modifications, and swimmer behavior guidance. For pool operators, voluntary PFAS monitoring, source water treatment, and promotion of PFAS-free personal care products among competitive swimmers represent proactive risk management measures ahead of potential regulatory requirements.
Recreational water PFAS represents an underappreciated exposure pathway—particularly for competitive swimmers who spend hours daily in PFAS-contaminated pool water—and warrants regulatory attention as the evidence base continues to develop.