Pollution Characteristics Analysis And Ecological Risk Assessment Of Triclosan And Triclocarban In Coastal Waters Of Bohai Bay

Triclosan?TCS?and Triclocarban?TCC?are the two typical substances in pharmaceuticals and personal care products?PPCPs?.Because of their high spectrum,they are often used as the main components of a variety of disinfectants.At present,there are no thresholds for TCS and TCC concentrations in waters.The potential impacts of TCS and TCC on ecosystems have not been fully appreciated.In this paper,species sensitivity distribution?SSD?was used to deduce the Predicted No Effect Concentration?PNEC?of TCS and TCC.Taking the surface water of the coastal waters of Bohai Bay as the research object,the pollution status of two substances in the area were monitored,and their ecological risks were evaluated.The toxicological data of TCS and TCC were collected and screened.The SSD model was established for acute and chronic toxicity data for freshwater and chronic toxicity data for seawater of two pollutants respectively.The best fitting function was selected to derive PNEC.The following results were obtained:for freshwater,the acute water PNEC for TCS was calculated as 216 ng·L^-1 and chronic PNEC was 50ng·L^-1;for seawater,the PNEC was 384 ng·L^-1.For freshwater,the acute water PNEC for TCC was calculated as 676 ng·L^-1 and chronic PNEC was 48 ng·L^-1;for seawater,the chronic criteria was 104 ng·L^-1.The monitoring results of the sampling points in the coastal waters of Bohai Bay in August and November of 2017:the range of TCS concentration in the two sample sites is ND⁷2.1 ng·L^-1 and ND⁸1.2 ng·L^-1 respectively,and the detection rate is more than 80%.The range of TCC concentration is ND⁵9.5 ng·L^-1 and ND⁵9.0ng·L^-1,respectively.The range of the detection rate exceeding 70%.Using the quotient method to characterize the ecological risks of TCS and TCC,the results show:the RQ variation range of TCS is 0¹.44 and 0¹.62,in August and November of 2017,respectively.Based on the acute and chronic PNEC for freshwater acute,and chronic PNEC for seawater,the ratio of the sampling sites at mid-high risk is 40%,70%,10%and 47.06%,82.35%,11.76%,respectively.The RQ variation range of TCC is 0¹.24 and 0¹.229 respectively.Based on the acute and chronic PNEC for freshwater acute,and chronic PNEC for seawater,the ratio of the sampling sites at mid-high risk is 0%,70%,60%and 0%,82.35%,64.71%,respectively.In the two sample sites,a significant proportion of the sampling points had RQ values greater than 0.1.