PFAS and Precursor Bioaccumulation in Freshwater Recreational Fish: Implications for Fish Advisories

Abstract

Per- and polyfluoroalkyl substances (PFAS) are a diverse class of fluorinated anthropogenic chemicals that include perfluoroalkyl acids (PFAA), which are widely used in modern commerce. Many products and environmental samples contain abundant precursors that can degrade into terminal PFAA associated with adverse health effects. Fish consumption is an important dietary exposure source for PFAS that bioaccumulate in food webs. However, little is known about bioaccumulation of PFAA precursors. Here, we identify and quantify PFAS in recreational fish species collected from surface waters across New Hampshire, US, using a toolbox of analytical methods. Targeted analysis of paired water and tissue samples suggests that many precursors below detection in water have a higher bioaccumulation potential than their terminal PFAA. Perfluorobutane sulfonamide (FBSA), a short-chain precursor produced by electrochemical fluorination, was detected in all fish samples analyzed for this compound. The total oxidizable precursor assay interpreted using Bayesian inference revealed fish muscle tissue contained additional, short-chain precursors in high concentration samples. Suspect screening analysis indicated these were perfluoroalkyl sulfonamide precursors with three and five perfluorinated carbons. Fish consumption advisories are primarily being developed for perfluorooctane sulfonate (PFOS), but this work reinforces the need for risk evaluations to consider additional bioaccumulative PFAS, including perfluoroalkyl sulfonamide precursors.

Uptake of Per- and Polyfluoroalkyl Substances by Fish, Mussel, and Passive Samplers in Mobile-Laboratory Exposures Using Groundwater from a Contamination Plume at a Historical Fire Training Area, Cape Cod, Massachusetts

“…Fish tissue concentrations for the REF exposure experiment provide a reasonable approximation of potential exposure for surface water organisms, as illustrated by the PFAS contamination plume, which discharges into Ashumet Pond, resulting in T-PFOS concentrations of 50 ± 4.1 ng L –1 (greater than T-PFOS concentrations of 7.2 ± 1.2 ng L –1 at REF). The REF male fish whole-body T-PFOS concentrations after 21-day exposures (1.4 ± 0.22 ng g –1 ) and the female fish whole-body T-PFOS concentrations (1.8 ± 0.49 ng g –1 ) were consistent with results for recreational fish collected from lakes in New Hampshire (mean = 6.8 ± 8.6 ng g –1 ; n = 43). The d21 REF fish mean T-PFOS concentration exceeded the New Hampshire reference dose value limit of ≤1.1 ng g –1 for daily consumption by adults.…”

“…34−36 Although studies of bioconcentration and bioaccumulation of PFAS in fish typically focus on kinetics and partitioning into internal organ tissues, whole-body and muscle tissues are preferred for assessing ecosystem risk and human consumption exposure. 35,37 Despite the extensive and rapidly growing literature on PFAS occurrence, fate, and effects, there are relatively few controlled studies (laboratory or field) reporting on bioconcentration factors (BCF) for PFAS in freshwater fish and mussels.…”

“…Assessing the occurrence and concentration of PFAS in aquatic environments using biotic and abiotic sampling is complicated by the many processes influencing their fate and transport, including sorption at physical interfaces and biodegradation. − Of particular importance for assessing environmental exposure and potential biological effects on aquatic organisms is the partitioning of PFAS between water and tissue. − Although studies of bioconcentration and bioaccumulation of PFAS in fish typically focus on kinetics and partitioning into internal organ tissues, whole-body and muscle tissues are preferred for assessing ecosystem risk and human consumption exposure. , Despite the extensive and rapidly growing literature on PFAS occurrence, fate, and effects, there are relatively few controlled studies (laboratory or field) reporting on bioconcentration factors (BCF) for PFAS in freshwater fish and mussels.…”

Weaponising microbes for peace

“…Moreover, there can be transmission, and in some cases bioaccumulation, of toxic chemicals within the food chain/food web (https://www.epa.gov/salish-sea/toxics-food-web), all the way to humans. For example: fungi accumulate heavy metals – including radioactive metals – so, if grown in contaminated soils/materials and gathered/harvested for human consumption, they can transmit toxic metals to the humans who eat them rice accumulates high levels of arsenic fish accumulate toxic polychlorinated‐biphenyls and ‐dioxins and humans eat the fish per ‐ and polyfluorinated alkyl substances (PFAS) – ‘Forever Chemicals’ – are a class of more than 4700 synthetic, highly persistent chemicals that do not occur in nature, some of which are known to have adverse health effects and bioaccumulate in the food web ( https://chemtrust.org/pfas/#:~:text=PFAS%20(Per%2D%20and%20polyfluorinated%20alkyl,do'not%20occur%20in%20nature; https://www.cdc.gov/biomonitoring/PFAS_FactSheet.html; Lewis et al, 2022; Pickard et al, 2022). …”

Total Oxidizable Precursor (TOP) Assay─Best Practices, Capabilities and Limitations for PFAS Site Investigation and Remediation

“…However, NTA data are challenging to quantify without standards, requiring targeted methods for quantification purposes . Although NTA was used recently as a semi-quantification method, the results showed high variability and overestimated concentrations compared to TOP assay results in many cases. , The bias in semi-quantified concentrations is in part due to limited analytical standards and in part due to the ionization or fragmentation differences when using surrogate reference standards. NTA is also time intensive, requires extensive interpretive expertise, and is not ideally suited to routine analysis.…”