Transfer of selected PFAS to muscle, liver and plasma of adolescent sheep

Per- and polyfluorinated alkyl substances (PFAS) are anthropogenic compounds that can be found in the environment worldwide and are also present in the food chain, especially in animal products. This study investigated the kinetics of uptake, distribution, and excretion of nine PFAS (PFBA, PFPA, PFHxA, PFOA, PFNA, PFDA, PFBS, PFHxS, PFOS) in 16 male lambs. Plasma, liver and dorsal muscle samples were analyzed. PFHxS was the dominant compound in plasma (5330 ± 200 μg/L) and dorsal muscle (347 ± 78 μg/kg), whereas PFOS was predominant in liver samples (1817 ± 152 μg/kg). To compare toxicokinetic of uptake, distribution and depletion, biotransfer factors (BTF), transfer rates (TR) and apparent plasma elimination half-lives were estimated directly from the data. Generally, long-chain compounds such as PFHxS, PFOS, PFNA and PFDA exhibited a stronger tendency to accumulate in animal tissue and were eliminated slower than short-chain compounds. Apparent plasma elimination half-lives ranged from 0.3 days (PFPA) to 57 days (PFOS). This study provides the first data on the toxicokinetic behavior of PFAS other than PFOA and PFOS in male lambs. Toxicokinetic parameters, such as apparent plasma elimination half-lives and BTFs will be useful for developing improved management recommendations.