Legacy and Novel Brominated Flame Retardants in Agricultural Soils in China (2011-2021): Concentration Level, Temporal Trend, and Health Risk Assessment

Polybrominated diphenyl ethers (PBDEs) and novel brominated flame retardants (NBFRs) have been extensively investigated in the terrestrial environment of China. In this study, agricultural soils from different regions in China from 2011 to 2021 were collected to investigate the contamination levels and temporal variation of PBDEs and NBFRs. The concentrations of ∑ 26 PBDEs and ∑ 5 NBFRs ranged from 0.144 to 215 ng/g dry weight (d.w.) and 0.186 to 144 ng/g (d.w.), with a mean value of 9.27 ng/g (d.w.) and 8.22 ng/g (d.w.), respectively. BDE-209 and DBDPE were the most predominant compounds among PBDEs and NBFRs. NBFR concentrations increased with time and the concentration levels in 2021, 2016, and 2013 were significantly higher than in 2011 ( p < 0.05). The ratios of ∑ 26 PBDEs and ∑ 5 NBFRs showed a decreasing trend and the ratios in 2021 and 2013 were significantly lower than that in 2011 ( p < 0.05), indicating the occurrence of NBFRs to replace PBDEs. Overall, this is the first study to comprehensively analyze the contamination burden and temporal trends of PBDEs and NBFRs in Chinese agricultural soils during a long period and will provide valuable basic data for future management of BFRs.