Bioaccumulation and Transfer of Legacy and Emerging Per- and Polyfluoroalkyl Substances throughout the Lifecycle of a Tropical Amphibian Species Fejervarya limnocharis

Abstract

Pollutant bioaccumulation in amphibians is complex owing to their unique physiological characteristics and biphasic lifecycle. This study investigated per- and polyfluoroalkyl substances (PFASs) in water, insects, and rice frogs (Fejervarya multistriata) throughout their entire lifecycle. The median total PFAS concentrations were 1.15–5.53, 65.6, 7.31, 7.33, and 2.24–31.6 ng/g dry weight in insect, egg, tadpole, juvenile frog, and adult frog samples, respectively. Concentrations of PFASs with protein–water distribution coefficients (log K_PW) > 2 decreased from eggs to tadpoles and were constant from tadpoles to frogs. By contrast, concentrations of PFASs with log K_PW < 2 reached apex concentrations in tadpoles and juvenile frogs. No growth dilution was observed for PFASs from juvenile to adult frogs. Stable isotope and fatty acid compositions in frog and insect samples indicated little change in diet sources during frog growth. The bioaccumulation factors of PFASs with log K_PW < 3 were decreased in tadpoles and frogs, suggesting preferential accumulation of low-proteinphilic PFASs from water. The distinct bioaccumulation profiles of PFASs during rice frog development emphasize the need for ecological and toxicological studies conducted throughout the amphibian lifecycle.