Organophosphate esters(OPEs), as a substitute for brominated flame retardants, are widely used in production and life, and their environmental pollution and toxic effects have attracted widespread attention. In this study, the concentrations and distribution characteristics of OPEs in seven major drainage basins of China were sorted out. The average daily dose of OPEs in Chinese adults, adolescents, and children was calculated to assess the health risks, and the reliability of the results was evaluated using Monte Carlo simulation. The toxic effect concentrations of 12 OPEs on aquatic organisms were investigated, and the species sensitivity distribution(SSD) curve was constructed to assess the ecological risk. The results showed that the 5th percentile concentration of ΣOPEs in the seven drainage basins was 52.61 ng·L-1 under the low exposure scenario. The median concentration of ΣOPEs in the seven basins was 499.74 ng·L-1, with trichloroethyl phosphate(TCEP), triethyl phosphate(TEP), and triethyl phosphate(1,3-dichloro-2-propyl) esters(TDCP) as the main contaminants. Under the high exposure scenario, the 95th percentile concentration of ΣOPEs in the seven basins was 1904.4 ng·L-1, 3.8 times that of the intermediate exposure scenario, and the Yangtze River Basin had the highest ΣOPEs concentration under the high exposure scenario. The health risk assessment showed that the non-carcinogenic risk of OPEs exposure through drinking water was within acceptable limits for different populations. Trimethyl phosphate(TMP), triisobutyl phosphate(TiBP), and TCEP were the main contributors to cancer risk. The results of ecological risk assessment showed that TCEP had medium ecological risk at the high exposure level, tributyl phosphate(TnBP) had medium ecological risk under the intermediate exposure scenario, and there was higher ecological risk under the high exposure scenario. Triphenyl phosphate(TPhP) had a risk quotient greater than 1 under the low, intermediate, and high exposure scenarios, and there was a high ecological risk, which requires special attention.
Keywords: Monte Carlo; distribution characteristics; drainage basins of China; organophosphate esters(OPEs); risk assessment.