Human exposure to PFOS and mercury through meat from baltic harbour seals (Phoca vitulina)

The overall aim of the present study was to assess human exposure to environmental contaminants from consumption of harbour seal (Phoca vitulina) meat in the southwestern Baltic Sea. For this purpose, muscle tissue from harbour seals (n = 27) was sampled from Danish locations in the period 2005-2015 and analysed for concentrations of total mercury (Hg), organochlorine contaminants such as polychlorinated biphenyls (PCBs) and organochlorine pesticides as well as perfluoroalkyl substances (PFAS) with particular focus on perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA). Hg, ∑PCB, PFOS and PFOA concentrations in the muscle tissue ranged between 0.27 and 4.76 μg g-1 wet weight (ww; mean: 1.38 μg g-1 ww, n = 27), 12.2-137 ng g-1 ww (mean: 47.5 ng g-1 ww, n = 10), 6.95-33.6 ng g-1 ww (mean: 15.8 ng g-1 ww, n = 10) and 0.16-0.55 ng g-1 ww (mean: 0.28 ng g-1 ww, n = 10), respectively. We compared the concentrations with literature-derived human tolerable weekly intake (TWI) values for mercury (1.3 μg kg-1 week-1), ∑PCB (2.1 μg kg-1 week-1), PFOS (0.013 μg kg-1 week-1) and PFOA (0.006 μg kg-1 week-1). The comparisons showed that the weekly consumption of harbour seal meat by children (weighing 30 kg), women (weighing 60 kg) and men (weighing 80 kg) should not exceed 28, 57 and 76 g (for Hg), 1.3, 2.7 and 3.5 kg (for ∑PCB), 25, 50 and 67 g (for PFOS) and 640, 1290 and 1720 g (for PFOA). In conclusion, Hg and PFOS are the contaminants of most importance in seal meat from this area with respect to existing tolerable intake rates and risks of adverse human health effects.