Occurrence and risk assessment of estrogenic compounds in the East Lake, China

Forty two surface water samples were collected in May and June of 2013 in five lakelets of the East Lake, China. Four steroid hormones (17 beta-estradiol (beta E2), estrone (E1), 17 alpha-estradiol (alpha E2) and 17 alpha-ethinylestradiol (alpha EE2)) were analyzed in these samples. Determination of four estrogenic compounds was performed on high performance liquid chromatography/mass spectrometry (HPLC/MS). beta E2 was detected with the highest detection frequency of 62% and its concentration range was from nd to 17.58 ng/L. The mean total concentration of four compounds increased with the order: Houhu lake (L5) (8.91 ng/L) < Niuchao lake (Li) (19.92 ng/L) < Guozheng lake (L2) (20.03 ng/L) < Tangling lake (L4) (22.65 ng/L) < Guandu lake (L3) (35.68 ng/L). Pollution sources of four compounds were mainly from municipal wastewater and water washed out from farm land fertilized with the waste of livestock or irrigated with water from livestock farm. The proportion of sample sites at high risk that compounds had effect" on fish population were 58.3% in Guozheng (L2) lake, 100% in Guandu (L3) lake, and 62.5% in Tangling (L4), Niuchao (L1) and Houhu (L5) lake, respectively. The mean beta E2 equivalent concentrations was at relatively high levels in L3 with 8.6 ng/L, Ll with 6.1 ng/L, L4 with 4.62 ng/L, L2 with 4.58 ng/L and L5 with 2.62 ng/L, respectively. Meanwhile, sampling sites at high risk generally were surrounded with hospitals, hotels and residential buildings where had high population density.