Organic UV Filters in the Surface Water of Nanjing, China: Occurrence, Distribution and Ecological Risk Assessment.

Abstract

Organic UV filters (OUV-Fs) are increasingly used for protection against UV irradiation. The widespread occurrence of OUV-Fs residues in aquatic systems has been reported, but little is known regarding their distribution and potential impact to the surface water in China. This study reports the occurrence, distribution and risk assessment of eight widely used OUV-Fs in the surface water of Nanjing. The results indicated butyl-methoxydibenzoylmethane, octyl-dimethyl-PABA and benzophenone-types (BP3, BP4 and BP1) were the most frequently detected compounds at concentrations of 3.63-104 ng/L. In general, the concentrations of OUV-Fs were decreased along the rivers; however, due to a substantial pollution load from the tributaries, higher concentrations of OUV-Fs were observed near the tributary inlet, compared to the other study areas. The risk assessment based on the calculated risk quotients (RQs) demonstrated that all OUV-Fs posed at least low risks to certain sensitive aquatic organisms, and BP3 posed high risk with RQ values of 1.64. It should be noted that the exclusion of adsorbed OUV-Fs might have contributed to an underestimation of the risk, therefore, it's necessary to assess both adsorbed and dissolved OUV-Fs in further studies.