Occurrence, spatial distribution, and ecological risk of benzotriazole UV stabilizers (BUVs) in sediments from Bohai sea of China

Benzotriazoles are a class of ultraviolet absorbents which absorb UV ranging from 280 to 400 nm and are widely used in personal care products and industrial production. Their residues in environmental matrices have received great concern in recent years, but most studies have focused on pollution in water and few have examined BUVs in marine sediments. In this study, we investigated the occurrence, potential sources, and ecological risk of 15 types of BUVs in the sediments of Bohai Sea in China for the first time. The total concentrations of the 15 BUVs ranged from 0.139 to 4.125 ng/g dw with a median concentration of 0.340 ng/g. UV-327 and UV-360 were predominant among the BUV congeners, accounting for 22.6% and 17.7% of the total concentration of Σ15BUVs, respectively. The detection frequencies of the BUV congeners generally exceeded 95%, reflecting the wide use and persistence of these chemicals. The concentrations of the BUV congeners in this study were one order of magnitude lower than those in other areas. Moreover, the distributions of BUVs presented a decreasing gradient from nearshore to offshore, indicating that coastal input was the main influencing factor. Two potential primary sources, plastic manufacturing and domestic wastewater, were identified via principle component analysis. The ecological risks of BUVs to aquatic organisms in the sediments were evaluated using the risk quotient (RQ) method. Generally, the risk to aquatic organisms from exposure to BUVs in Bohai Sea could be considered low at the measured concentrations. While our study provides important new insight into the ecological risks of BUVs in the estuary, further research on the pollution levels and toxicity risks of BUVs in Bohai Sea should be conducted to better understand the ecological effect of these pollutants.