Global and historical Per- and Polyfluoroalkyl Substances (PFAS) exposure in North Atlantic Right Whales

Per- and Polyfluoroalkyl Substances (PFAS) are of growing concern for their potential adverse environmental and human health effects. PFAS compounds demonstrate remarkable environmental stability and are globally dispersed. Baleen whales are a category of migratory whale species characterized by the formation of baleen used to filter small prey from seawater. Baleen whales are globally distributed and tend to migrate between high-latitude feeding grounds and low-latitude breeding grounds. North Atlantic Right Whales, NARW (Eubalaena glacialis) are found throughout the North Atlantic in European and North American populations, with the latter being the most populated. NARWs are critically endangered, with an estimated 360 individuals and only 70 breeding females. Therefore, it is vital to assess all threats to the species' survival. Whales have been documented to accumulate persistent organic pollutants (POPs) but are challenging to study. Current methods for assessing POPs in whales rely on soft tissue obtained from necropsies of beached whales. Baleen, composed mainly of keratin, accumulates PFAS, which has a documented affinity for proteins. By analyzing baleen sections, PFAS exposure can be evaluated throughout the life history of the whale. In addition, PFAS concentrations in the plate can be correlated with confirmed sightings to determine where the whale was when the contamination was absorbed. From this, we can determine not only the exposure profile of the whale but also regional and global PFAS distribution. This study aims to determine spatial and temporal PFAS profiles in two female NARWs. Plates were sections and digested in 1.0 M KOH in MeOH for 24 hours. Samples were passed through an EnviCarb^TM SPE tube to remove solubilized protein and analyzed for 42 legacy and emerging PFAS compounds. A Shimadzu Triple-Quadrupole Liquid Chromatography-Mass Spectrometer in Multiple Reactions Monitoring (MRM) mode was used to quantify PFAS concentrations. PFAS content in baleen is correlated with recorded pregnancies, lactation periods, and geographic location as confirmed by coincident concentrations of the sex hormone progesterone in baleen and visual shipboard observations of whales to confirm pregnancies and the geographic locations of whales during their life history. A detailed life-cycle exposure of PFAS in each whale has been established.