Per- and polyfluoroalkyl substances (PFAS) accumulation in fish occupying different trophic positions from East Canyon Creek, a seasonally effluent-dominated river, Utah, USA

Fish and seafood are considered a major source of human dietary exposure to per- and polyfluoroalkyl substances (PFAS). In this study, we examined levels of 35 PFAS in fish samples of brown trout and mottled sculpin, which occupy different trophic positions, collected in 2014 from East Canyon Creek in Utah, USA. We observed 20 PFAS with ∑₂₀PFAS ranging from 0.46-63.9 ng/g and from <LOQ-52.1 ng/g wet weight in sculpin and brown trout, respectively. Among detected compounds, PFOS was measured at highest levels ranging 3.8-46.5 ng/g in sculpin, which occupies a lower trophic level, and 2.5-38.4 ng/g in brown trout, which occupies a higher trophic position. The most frequently detected PFAS were PFDA and FOSA, and these contaminants were found in 93% and 81% of fish samples; however, we did not identify appreciable PFAS biomagnification. To evaluate potential risk associated with consumption of fish, we calculated risk-based consumption limits using European Food Safety Authority (EFSA) regulated values of maximum levels (MLs) and total weekly intake for four regulated PFAS: PFOA, PFNA, PFHxS, and PFOS. The levels of regulated PFAS exceeded at least one of the MLs in 74% of sculpin samples and 45% of brown trout samples. Based on calculated weekly intake for the sum of the four regulated PFAS, a typical adult would need to consume 4.2 and 5.6 meals per week of whole body sculpin and brown trout, respectively, to reach the tolerable weekly intake (TWI) of 4.4 ng/kg body weight per week set by EFSA.