Occurrence, Spatial Distribution, and Risk Assessment of Brominated Flame Retardants in Farmland Soils of Typical Provinces in China

Abstract

In the present study, we investigated the occurrence, distributions, and potential risks of brominated flame retardants in farmland soils across 18 provinces of China. The total mean concentrations of the BFRs were in order DBDPE > BDE209 > HBB > TBB. DBDPE concentration was highest at 177.21 ng/kg, revealing its long-term use and persistence.  It was found that spatially, DBDPE was highest in the south (Sichuan and Guangdong provinces) and north (Jilin province), and BDE209 was highest in the south (Sichuan province) and north (Jilin province), while HBB was highest in the south (Sichuan province) and east (Anhui and Zhejiang provinces) of China. Comparisons of the results in this study to other reported studies in different locations indicated that the studied BFRs concentrations were higher in China. Pearson correlation between BFRs and soil properties indicated a significantly high association.  The hazard quotients of ecological risks ranged from 8.76 × 10-6 to 1.16 × 10-2 (< 1) while non-carcinogenic human risk evaluation via ingestion, inhalation and dermal absorption were evaluated as for adults 7.05 × 10-7-7.48 × 10-4 (< 1) and for children 2.99 × 10-4-4.30 × 10-2 (< 1). The risk levels were further confirmed through Monte Carlo simulations. Although the risk evaluations of BFRs in this study were low, it is still necessary that further work should be carried out to establish a suitable threshold limit for farmland soils contamination and identify other exposure pathways.

Keywords: Brominated flame retardants, Farmland soil, Monte Carlo Simulation, Spatial distribution, Risk assessment.