Evaluating the environmental occurrence of per- and polyfluoroalkyl substances (PFAS) and potential exposure risk for recreational shellfish harvesters in the Great Bay Estuary, New Hampshire

Abstract

Background: Shellfish may be an important contributor to PFAS exposure from seafood consumption. Yet, shellfish consumption patterns are distinct from other seafood varieties and PFAS exposure via shellfish consumption has not been well studied, especially among recreational harvesters who may be exposed to PFAS through direct consumption of shellfish, incidental ingestion of sediment, and dermal absorption.

Methods: Collocated surface water, sediment, and bivalve shellfish samples were collected in the Great Bay Estuary, a prominent estuary in New Hampshire, USA with multiple known PFAS sources. All media were analyzed for 27 PFAS compounds via UPLC-MS/MS. Human health risk of PFAS exposure from recreational shellfish harvesting was estimated for typical and high seafood consumers across multiple exposure routes using available health guidance values.

Results: PFAS were detected in all Great Bay water, sediment, and shellfish samples. PFAS concentrations varied spatially, and profiles varied by media type, with shorter chain compounds found in water and longer chain compounds found in sediment and shellfish. For adults, PFAS exposure risk from recreational shellfish harvesting was greatest from direct consumption of shellfish (>99 % of estimated daily PFAS dose), followed by dermal absorption and incidental sediment ingestion. For children, dermal absorption and incidental ingestion were also important, contributing up to 10 % of estimated daily exposure. PFAS exposure risk from consuming razor clams exceeded the reference hazard quotient of 1 for multiple compounds among the general population that consumes typical or greater amounts of seafood, and among persons of childbearing age and young children who consume high amounts of seafood.

Conclusions: High frequency recreational shellfish harvesting and consumption may increase exposure to certain PFAS.

Keywords: Bivalves; Exposure pathways; Per- and polyfluoroalkyl substances (PFAS); Risk assessment; Seafood consumption; Sediment; Water.