Estimating estrogen release and load from humans and livestock in shanghai, china.

The estrogens estrone (E1), 17β-estradiol (E2), and 17α-ethynylestradiol (EE2) cause potent endocrine disruptive effects on aquatic wildlife. Currently, four sources of released estrogens exist in Shanghai: treated effluent from municipal wastewater treatment plants (WTPs); wastewater discharge from livestock farms; untreated or simply digested sewage from rural households; and runoff from farmland with livestock manure (LM) applied and irrigated with livestock wastewater (LW). A modified estimation method for estrogen release, in consideration of the difference in estrogen excretion rates between Caucasian and Oriental people and estrogen reduction in livestock wastes, was presented in the study. Based on the estimation method, we estimated the amount of estrogen release from humans and livestock and analyzed the spatially explicit distribution of estrogen loads. By comparing the four estrogen sources, the amount of estrogens released to water environments from livestock (56.8 g d), in terms of E2 equivalents (EEQ), was nearly twofold higher than the EEQ from humans (35.2 g d), which accounted for 61.0% of the total EEQ in Shanghai. Regarding the livestock EEQ, land-applied and irrigated EEQ via surface runoff to water environments (0.11 g d) was obviously low compared with the EEQ of LW directly released into adjacent waterways (56.7 g d). Therefore, the LW was the major contributor to estrogenic risk to the water environment in Shanghai. The spatial distribution of estrogen loads indicated that the highest EEQ loads were in the southern region of Pudong New Area and the eastern and central regions of Fengxian District.