Perfluorinated Alkyl Acids in Wildlife

The first measurements of perfluorinated alkyl acids (PFAAs) in wildlife from the aqueous and terrestrial environment showed their ubiquitous presence. Since the initial studies in 2001 their presence, distribution, and fate in the environment has broadly been studied. PFOS, perfluorooctane sulfonate, is the dominant and most frequently detected PFAA in wildlife from around the world. Additionally long-chain (greater than eight carbons long) perfluoroalkyl carboxylates (PFCAs) have also been measured in biota, with some of the highest concentrations being measured in wildlife from the Arctic. The majority of temporal studies have shown PFOS concentrations increasing over time; however, more recent observations have started showing a decline in PFOS in some wildlife. Long-chain PFCA (greater than eight carbons) concentrations have shown an increase in recent temporal studies, with PFCA concentrations comparable to those of PFOS measured in the same animals. Many food-web studies have examined bioaccumulation and biomagnification of PFAAs. Most studies have shown biomagnification of PFAAs, with PFOS especially having a higher biomagnification potential compared to the PFCAs. While much work has been done during the 15 years PFAAs have been examined in wildlife, there are still gaps. There has been limited work on wildlife from terrestrial ecosystems. There are also many geographical locations that have very limited studies or lack them altogether. Additional monitoring of the terrestrial environment and the inclusion of new geographical locations are needed to help understand the global distribution of PFAAs in wildlife.