Distributions and biomagnification of polybrominated diphenyl ethers in a grassland ecosystem food chain

Abstract

The concentrations, distributions, and biomagnification of polybrominated diphenyl ethers (PBDEs) in environmental and biological media in a terrestrial grass ecosystem were studied, The total PBDE concentrations in grasses were 4.00 × 10−2 to 4.28 ng·g−1. The total PBDE concentration in weasel muscle (23.2 ng·g−1 l.w.) was the highest concentrations of all animal tissue samples, and the total PBDE concentration in hair from local herdsmen (22.2 ng·g−1 l.w.) was second highest. Less-brominated PBDEs were found to be more strongly biomagnified than more-brominated PBDEs in the grassland food web. PBDEs were found to be much more strongly biomagnified in the food chains of homothermic animals than heterothermic animals. More-brominated PBDEs were not markedly biomagnified in the grassland food web. For example, BDE-153 was not biomagnified in the grassland wildlife food chain but was clearly biomagnified through the sheep, cattle, or horse hair to human hair route. The biomagnification factors and log Kows negatively correlated for the toad–snake, lizard–snake, and mouse–weasel food chains. The ability of PBDE congeners to become enriched generally decreased as the log Kow increased, and this decrease occurred 100–1000 times more strongly for homothermic animals than heterothermic animals.