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Limited data are available for the occurrence of more recent per and polyfluorinated alkyl substances (PFAS) in marine mammals, especially from the St. Lawrence Estuary and Gulf. This study investigates the occurrence of PFAS in liver and muscle tissues of various marine mammals, including the harbor seal, gray seal, harp seal, hooded seal, harbor porpoise, white-sided dolphin, white-beaked dolphin, and True's beaked whale. Among the 80 target PFAS (including PFCAs, PFSAs, Cyclic PFSA, FASAs/FASAAs, FTCAs/FTUCAs, FTSAs, Ether-PFAS, diPAPs, and ESI + ECF precursors) perfluorooctanoic sulfonate (PFOS) dominates in all the marine mammal species and several other longchain PFCAs, such as PFNA, PFDA, PFUnA, PFTrDA, and PFHxDA, were detected at 100% frequency in both muscle and liver samples. PFDoA and 7:3 fluorotelomer carboxylic acid (7:3 acid) also showed a 100% detection frequency for liver samples. Harp seal tissues displayed notably low PFAS concentrations, with average total PFAS concentrations of 7 ng/g (ww: wet weight) in muscle and 44 ng/g (ww) in the liver. In contrast, the white-sided dolphin exhibited the highest average concentrations, reaching 39 ng/g (ww) in muscle and 334 ng/g (ww) in liver samples. The Pearson correlation analysis reveals a strong correlation between the concentration of PFOS, perfluoroalkyl carboxylic acids (PFCAs), and electrochemical fluorination (ECF) precursors. Species at the top of the marine food chain (harbor porpoise, white sided dolphin, and white beaked dolphin) presented the highest concentrations of PFAS, particularly PFOS and long-chain PFCAs, highlighting the need for an increased regulation of these persistent molecules in order to protect marine mammal's health. [ABSTRACT FROM AUTHOR]

Objective: To document perfluoroalkyl acids (PFAA) and bisphenol-A (BPA) exposure in four First Nation communities in northern Quebec compared with the Canadian Health Measures Survey (CHMS Cycle 5 2016–2017) and examine the associations between dietary consumption and chemical exposure. Design: We used cross-sectional data from the JES-YEH! project conducted in collaboration with four First Nation communities in 2015. A FFQ collected information on diet, and PFAA and BPA were measured in biological samples. We used generalised linear models to test the associations between food intake and chemical biomarkers. Setting: Northern Quebec. Participants: Youth aged 3–19 years (n 198). Results: Mean perfluorononanoic acid (PFNA) levels were significantly higher in JES-YEH! than CHMS, and BPA levels were higher among those aged 12–19 years compared with CHMS. Dairy products were associated with PFNA among Anishinabe and Innu participants (geometric mean ratio 95 % CI: 1·53 (95 % CI 1·03, 2·29) and 1·52 (95 % CI 1·05, 2·20), respectively). PFNA was also associated with ultra-processed foods (1·57 (95 % CI 1·07, 2·31)) among Anishinabe, and with wild fish and berries (1·44 (95 % CI 1·07, 1·94); 1·75 (95 % CI 1·30, 2·36)) among Innu. BPA was associated with cheese (1·72 (95 % CI 1·19, 2·50)) and milk (1·53 (95 % CI 1·02, 2·29)) among Anishinabe, and with desserts (1·71 (95 % CI 1·07, 2·74)), processed meats (1·55 (95 % CI 1·00, 2·38)), wild fish (1·64 (95 % CI 1·07, 2·49)) and wild berries (2·06 (95 % CI 1·37, 3·10)) among Innu. Conclusions: These results highlight the importance of better documenting food-processing and packaging methods, particularly for dairy products, and their contribution to endocrine disruptors exposures as well as to promote minimally processed and unpackaged foods to provide healthier food environments for youth in Indigenous communities and beyond. [ABSTRACT FROM AUTHOR]

Nunavimmiut (Inuit of Nunavik, Northern Quebec, Canada) exhibit a high selenium (Se) status because of their frequent consumption of marine mammal foods. Indirect evidence from our previous studies had suggested that selenoneine – a novel selenocompound – may be accumulating in the blood of Nunavimmiut. We used a liquid-chromatography/inductively coupled tandem mass spectrometry (LC-ICP-MS/MS) method to measure concentrations of selenoneine and its methylated metabolite Se-methylselenoneine in archived red blood cells (RBC) obtained from 210 Nunavimmiut living in communities along the Hudson Strait, where marine mammal hunting and consumption are most frequent in Nunavik. This method was adapted to quantify selenoneine and its methylated metabolite in beluga mattaaq, an Inuit delicacy consisting of the skin with the underlying layer of fat and the major dietary source of Se for Nunavimmiut. Total selenium concentration was also measured in RBC and beluga mattaaq samples by isotope dilution ICP-MS/MS. The median selenoneine concentration in RBC was 413 μg Se/L (range = 3.20–3230 μg Se/L), representing 54% (median) of total Se content (range = 1.6–91%). Quantification of selenoneine in five beluga mattaaq samples (skin layer) from Nunavik revealed a median concentration of 1.8 μg Se/g wet wt (range = 1.2–7.4 μg Se/g), constituting 54% (median) of the total Se content (range = 44–74%). Se-methylselenoneine was also detected in Inuit RBC but not in beluga mattaaq, suggesting that selenoneine undergoes methylation in humans. Selenoneine may protect Nunavimmiut from methylmecury toxicity by increasing its demethylation in RBC and in turn decreasing its distribution to target organs. Image 1 • LC-ICP-MS/MS was used to quantify selenoneine and Se-methylselenoneine in RBCs. • Selenoneine represented 54% of total Se content in Inuit RBCs. • Selenoneine was also the major Se species in beluga mattaaq – an Inuit delicacy. • Selenoneine may protect Inuit against methylmercury toxicity. [ABSTRACT FROM AUTHOR]

Perfluoroalkyl substances (PFASs) are found in several consumer goods. Exposure to PFASs in children has been associated with alteration in thyroid hormones, which have critical roles in brain function. In 2015, 198 children and youth (3–19 y) were recruited as part of the pilot project Jeunes, Environnement et Santé /Youth, Environment and Health (JES!-YEH!), realized in collaboration with four First Nation communities in Quebec. We aimed to evaluate serum concentrations of PFASs in relation to concentrations of thyroid-stimulating hormone (TSH), free thyroxine (T4) and thyroglobulin while adjusting for relevant confounders. PFASs (PFOS, PFOA, PFHxS, PFNA), 2,2′,4,4′-Tetrabromodiphenyl ether (PBDE-47) thyroid parameters (TSH, free T4, and thyroglobulin) were measured in serum samples of 186 participants. Iodine, creatinine, and cotinine were measured in urine samples. Serum levels of PFASs were compared to those measured in the general Canadian population and elsewhere. Multivariate regression analyses were performed to determine associations between PFASs and TSH, free T4 and thyroglobulin. PFOS, PFOA and PFHxS serum concentrations were low. However, PFNA concentrations among participants aged 12 to 19 years old from Anishinabe communities were three times higher than those measured in the Canadian Health Measures Survey (2009–2011) for the same age group (Geometric Means: 3.01 μg/L and 0.71 μg/L, respectively) and were particularly higher in the Anishinabe participants aged 6 to 11 years old (GM: 9.44 μg/L). Few participants had levels of TSH, free T4, and thyroglobulin outside age-specific paediatric ranges. When adjusted for relevant covariates and other contaminants, PFNA serum concentrations were positively associated with free T4 levels (Adjusted β = 0.36; p = 0.0014), but not with TSH and thyroglobulin levels. No association was observed between the other PFAS and thyroid hormones parameters. This pilot project reveals among the highest exposure to PFNA in children reported until today, and suggests effects of PFNA as an endocrine disruptor, highlighting the importance of investigating the sources and effects of disproportionate exposure to emerging contaminants in some indigenous communities and ban all PFAS at the international scale. • Serum PFOS, PFOA, PFHxS and PFNA were measured in 186 children from four First Nations communities in Quebec. • PFNA exposure among Anishinabe participants was among the highest reported to date in children and youth. • Free T4 were positively associated with PFNA concentrations in adjusted models. • International actions to include all PFAS in the Stockholm Convention are urgently needed. [ABSTRACT FROM AUTHOR]

Selenium (Se) is a trace mineral essential to human health, and is especially abundant in marine foods consumed by Inuit populations in Nunavik (northern Quebec, Canada), leading to exceptionally high whole blood Se levels. While most epidemiological studies to date examine plasma or whole blood Se, little is known about the health implications of specific Se biomarkers (e.g. selenoproteins and small Se compounds). Selenoneine, a novel Se compound, is found in high concentrations in marine foods (and particularly beluga mattaaq) and the red blood cells (RBCs) of populations that consume them. We report here RBC selenoneine concentrations in a population of Inuit adults (n = 885) who participated in the Qanuippitaa ? 2004 survey. Simple associations between RBC selenoneine and other Se and mercury (Hg) biomarkers were assessed using Spearman correlations and linear regressions. Wilcoxon ranksum tests were used to examine differences in biomarkers and characteristics between tertiles of RBC selenoneine concentration. A multiple linear regression analysis was used to determine factors (sociodemographic, lifestyle, and dietary) associated with RBC selenoneine concentrations. Selenoneine comprised a large proportion of whole blood Se and RBC Se in this population. Age and sex-adjusted geometric mean RBC selenoneine concentration was 118 μg/L (range: 1–3226 μg/L) and was much higher (p = 0.001) among women (150.3 μg/L) than men (87.6 μg/L) across all regions of Nunavik after controlling for age, region, and diet. RBC selenoneine was highly correlated with RBC Se (r s = 0.96, p < 0.001) and whole blood Se (r s = 0.89, p < 0.001), but only weakly correlated with plasma Se (r s = 0.13, p < 0.001). Overall, increasing age (standardized β = 0.24), higher body-mass index (BMI; β = 0.08), female sex (β = 0.10), living in a Hudson Strait community (compared to Hudson Bay and Ungava Bay; β = 0.38), and consuming beluga mattaaq (g/day; β = 0.19) were positively associated with RBC selenoneine. Meanwhile, consumption of market meats (g/day; β = −0.07) was negatively associated with RBC selenoneine. RBC selenoneine is an important biomarker of Se dietary intake from local marine foods in Inuit populations. Further studies are needed to examine the health effects of selenoneine intake and the underlying mechanisms for sex differences among Inuit populations. • Selenoneine is a major selenium compound in the red blood cells of Inuit adults • Selenoneine levels are higher among women, elderly individuals, and those consuming high amounts of beluga mattaaq • Further research is needed to assess the origin, kinetics, and health impacts of selenoneine [ABSTRACT FROM AUTHOR]