Estimation of human-origin estrone and 17β-estradiol concentrations in the Han River, Seoul, South Korea and its uncertainty-based ecological risk characterization

Abstract

Estrogens originated from humans can reach ambient water and possibly cause significant ecological risks. In this study, the quantities of human-origin estrone (E1) and 17β-estradiol (E2) in the influent and effluent of four sewer treatment plants (STPs) in Seoul, South Korea were estimated using a demographic model. A Monte Carlo simulation was used to assess the quantitative uncertainty of estimated E1 and E2 concentrations. Mean concentrations of E1 and E2 estimated for STP influents ranged from 29.5 to 38.4 and 7.5 to 9.7ng/L, respectively. Meanwhile, mean concentrations of E1 and E2 estimated for STP effluents were 4.9 to 6.6 and 0.28 to 0.36ng/L, respectively. These estimated values are similar to measured data as reported in the literatures within the range of uncertainty based on the Monte Carlo simulation. The hazard quotient (HQ) value in the main stem of the Han River was calculated to be far less than 1 because of the dilution effect of the Han River's abundant flow, indicating that most of the Han River ecosystem will not be influenced by these endogenous estrogens. With a 95% cumulative probability, HQ values in the main stem of the Han River for the Jungrang, Nanji, Tanchun, and Seonam STPs were less than 0.18, 0.07, 0.08, and 0.15, respectively. Nevertheless, HQ values >1 were observed in the vicinity of the STP outlets when using the numerical modeling. Our results show that the endocrine disruption potential of E1 and E2 around STP outlets in the main stem of the Han River must be monitored carefully.