Polybrominated diphenyl ethers in farmland soils: Source characterization, deposition contribution and apportionment

Polybrominated diphenyl ethers (PBDEs), a group of persistent organic pollutants (POPs), are caused for concern recently due to their adverse health effects and environmental ubiquity. In this study, atmospheric and soil PBDE levels in Taizhou, one of the largest WEEE dismantling areas in the world, were measured, ranging from 884 to 2791pgm−3 with an average of 1968pgm−3 for atmosphere and 2.96 to 200ngg−1dry weight (dw) with the mean of 65.2ngg−1dw for farmland soils, respectively. The close connection between soil PBDE accumulation and atmospheric deposition was also revealed by the estimation of the annual PBDE deposition flux (3.1±0.9mgm−2a−1) and the similarity between deposited congener pattern and soil congener profile. Positive matrix factorization (PMF) was conducted to extract possible sources of farmland soil PBDEs and to calculate their contributions. Based on the measured source profiles of PBDE-related activities, five sources were identified representing WEEE dumping, WEEE dismantling, WEEE open burning, residential waste dismantling, and residential waste open burning. WEEE-related recycling activities contributed primary percentage (52%) to farmland soil PBDE concentration, and open burning was an important pathway for PBDEs entering the environment. •PMF was performed for identifying activity-linked PBDE sources.•PBDE congener profiles of recycling activities were measured for data accumulation.•Sources of PBDE contamination in farmland soil were revealed and initially verified.