Distribution and bioconcentration of seven Polybrominated diphenyl ethers (PBDEs) on the Qinghai-Tibet Plateau

Abstract Poly Brominated Diphenyl Ethers (PBDEs) are typical persistent organic pollutants (POPs), but studies on their distribution in terrestrial ecosystems at various trophic levels are scarce. The concentrations of PBDEs in soil, grass and rat liver ranged from 29.1 to 91.6, 71.5 to 644.4 and 43.2 to 519.0 ng g-1 dw, respectively, with BDE-154 predominating in all samples. A clear enrichment occurred from soil to grass in the soil-grass-plateau pika food chain, and a less clear trend of enrichment from grass to plateau pika. By correlation analysis, pollutants in soil and grass are not strongly correlated, so it can be assumed that some of the contaminants in grass come from other sources. A correlation comparison of contaminant concentrations in grass and liver, the majority of the substances (BDE-47, BDE-100, BDE-154, BDE-183) were found to be strongly correlated, this is related to the fact that grass is the main source of food for plateau pika in the Qinghai-Tibetan Plateau region. Highly brominated contaminants are generally more concentrated in each medium than lowly brominated contaminants. Only three contaminants (BDE-28, BDE-153 and BDE-154) be detected in all soil sample, yet 7 PBDEs detected in grass and liver samples, PBDEs are widely found in soil, grasses and plateau pika on the Qinghai-Tibetan plateau. According to the principal component analysis, the distribution pattern of pollutants is affected by many factors, and the pollutants in the Qinghai-Tibet Plateau may have the same source.