An arctic terrestrial food-chain bioaccumulation model for persistent organic pollutants

A model representing the bioaccumulation of persistent organic pollutants (POPS) in arctic terrestrial mammalian food chains is developed, parametrized, tested, and analyzed. The model predicts concentrations of POPS in lichen, caribou (Rangifer tarandus), and wolf (Canis lupus) food-chains of Canada's central and western arctic region from measured concentrations in air and snowpack meltwater. The model accounts for temporal and seasonal variation in diet composition, life-stage, body weight, and fat content over the life-span of the animal. Model predicted concentrations of 25 organic chemicals forecasted for caribou and wolves from Cambridge Bay (69degrees07' N 105degrees03' W), Inuvik (68degrees18' N 133degrees29' W) and Bathurst Inlet (64degrees15' N 113degrees07' W) are shown to be in good agreement with the observed data. The model illustrates a strong relationship between biomagnification factors and chemical K-OA and illustrates the effect of age, sex, and temperature on POPS bioaccumulation. Model results show that POPS with K(OA)s < 10(5) do not biomagnify in arctic terrestrial food-chains, while substances that exhibit log K(OA)s > 5 and also exhibit a log K-OW > 2, show significant bioaccumulation in arctic terrestrial food-chains. The model shows that persistent low K-OW (K(OW)s < 10(5)) but high KOA substances such as beta-HCH, 1,2,4,5 tetrachlorobenzene, and beta-endosulfan biomagnify in terrestrial mammals.