Brain region-specific perfluoroalkylated sulfonate (PFSA) and carboxylic acid (PFCA) accumulation and neurochemical biomarker Responses in east Greenland polar Bears (Ursus maritimus)

Assessment of perfluorooctane sulfonate and perfluorooctanoic acid exposure through fish consumption in Italy

“…These useful properties lend PFASs an important commercial value, which resulted in their employment for over 60 years in a large number of industrial and consumer applications, including stain-resistant coatings, oil-resistant claddings applied to food packaging materials, firefighting foams, insecticides and detergents (Prevedouros et al , 2006; Lindstrom et al , 2011). The extended production of PFASs during the last 60 years, combined with their high resistance against thermal degradation, hydrolysis, photolysis and biodegradation, have resulted in their global distribution, persistence in the environment, even in areas far from anthropogenic activities, and accumulation in biota (Ahrens and Bundschuh, 2014; Eggers Pedersen et al , 2015). Their potential to accumulate is not fully understood yet, depending on each compound’s chemical structure (Conder et al , 2008), however it is known that, unlike other persistent halogenated compounds, they have high affinity to proteins and are then easily found in human plasma, where they have a long half-life: Sundström et al (2012) estimated a mean elimination half-life of 2665 days for perfluorohexanesulfonate.…”

Per- and Polyfluoroalkyl Substances (PFAS) Neurotoxicity in Sentinel and Non-Traditional Laboratory Model Systems: Potential Utility in Predicting Adverse Outcomes in Human Health

“…This indicates that there is generally an upregulation of oxidative stress mechanisms with increased levels of PFAS in the brain. This study also found that monoamine oxidase activity, one of the main enzymes that metabolizes catacholamines such as dopamine, serotonin, and norepinephrine, was positively correlated with levels of PFTrDA, total perflurocarboxylates, and trended to correlate with PFDoDA in the occipital lobe and with levels of PFOS, total perfluorosulfonates, PFUnDA, PFDoDA, and total perfluorocarboxylates in the whole brain (Table 3) [52]. There was also a negative correlation between the density of dopamine D2 receptors and PFUnDA, PFDoDA, PFTrDA, and total perfluorocarboxylates in the temporal cortex and a borderline negative correlation with PFTrDA and total perfluorocarboxylates in the cerebellum (Table 3) [52].…”

“…U. maritimus in East Greenland had liver levels of PFAS averaging 3546 ng/g wet weight while male U. maritimus had an average of 22.92 ng/g wet weight PFOS, 28.82 ng/g total perfluorosulfonates, 1.09 ng/g PFOA, and 99.40 ng/g total perfluorocarboxylates in the brain (Table 1) [42,52]. Another study on U. maritimus mothers found plasma levels of total PFAS to be 539.0 ± 20.8 ng/g wet weight, with PFOS and PFOA levels equaling 431.9 ± 17.0 ng/g wet weight and 6.4 ± 0.6 ng/g wet weight [68].…”

“…Another study on U. maritimus from East Greenland studied the effects on various parts of the brain [52]. Glutathione synthase activity was positively correlated with levels of PFOS, total perfluorosulfonates, and perfluoroundecanoate (PFUnDA) and borderline correlated to levels of perfluorododecanoate (PFDoDA), perfluorotetradecanoate (PFTrDA), and total perfluorocarboxylates in the occipital lobe, and positively correlated with PFOS and total perfluorosulfonates in the frontal cortex while being negatively correlated with total perfluorosulfonates in the hypothalamus (Table 3) [52]. This indicates that there is generally an upregulation of oxidative stress mechanisms with increased levels of PFAS in the brain.…”

Initial study on the possible mechanisms involved in the effects of high doses of perfluorooctane sulfonate (PFOS) on prolactin secretion

“…Moreover, PFOS can cross the bloodebrain barrier (Austin et al, 2003) and be accumulated in the hypothalamus, (Austin et al, 2003) presenting neurotoxicity (Long et al, 2013;Pereiro et al, 2014;Dong et al, 2015). This chemical even seems to induce some alterations in neurochemical signaling (Eggers Pedersen et al, 2015) and could have behavioral effects, which were observed in East Greenland polar bears and in rats, respectively .…”