Spatiotemporal variation and risk assessment of phthalate acid esters (PAEs) in surface water of the Yangtze River Basin, China.

Spatiotemporal variation, potential sources, and risk assessment of phthalate acid esters (PAEs) in surface water of the Yangtze River Basin were investigated. Total cumulative concentrations of 15 PAEs (ΣPAEs) ranged from 1594.47 ng·L to 5155.50 ng·L, and the dominant components were di (2-ethylhexyl) phthalate (DEHP) (35.9-60.1%), dibutyl phthalate (DBP) (16.6-38.8%), and diisobutyl phthalate (DIBP) (6.7-18.2%). ΣPAEs in surface water showed a trend of normal season > wet season > dry season. ΣPAEs increased from the upstream (2341.7 ± 428.5 ng·L) to the mid- and downstream (3892.1 ± 842.8 and 2504.3 ± 355.9 ng·L, respectively), indicating the influence from production and consumptions of plasticizer-containing items. PAEs additives emission from daily necessities (28.9-62.3%) and construction and industrial production (18.7-31.2%) were the dominant sources of PAEs in this study. The risk quotient (RQ) method was employed to assess the potential ecological risk of specific components. High ecological risk of DEHP to the sensitive algae and crustacean, together with moderate ecological risk of DEHP and DIBP to the sensitive fish species were found in surface water regardless of the region and season. The spatial distribution of RQ values showed an increasing trend from the upstream to the midstream and downstream of the Yangtze River, indicating the influences from regional urbanization and industrialization levels.