Occurrence of androgens and progestogens in wastewater treatment plants and receiving river waters: comparison to estrogens.

Research has shown that exposure to androgens and progestogens can cause undesirable biological responses in the environment. To date, however, no detailed or direct study of their presence in wastewater treatment plants has been conducted. In this study, nine androgens, nine progestogens, and five estrogens were analyzed in influent and final effluent wastewaters in seven wastewater treatment plants (WWTPs) of Beijing, China. Over a period of three weeks, the average total hormone concentrations in influent wastewaters were 3562 (Wujiacun WWTP)-5400 ng/L (Fangzhuang WWTP). Androgens contributed 96% of the total hormone concentrations in all WWTP influents, with natural androgen (androsterone: 2977±739 ng/L; epiandrosterone: 640±263 ng/L; and androstenedione: 270±132 ng/L) being the predominant compounds. The concentrations of synthetic progestogens (megestrol acetate: 41±25 ng/L; norethindrone: 6.5±3.3 ng/L; and medroxyprogesterone acetate: 6.0±3.2 ng/L) were comparable to natural ones (progesterone: 66±36 ng/L; 17α,20β-dihydroxy-4-progegnen-3-one: 4.9±1.2 ng/L; 21α-hydroxyprogesterone: 8.5±3.0 ng/L; and 17α-hydroxyprogesterone: 1.5±0.95 ng/L), probably due to the wide and relatively large usage of synthetic progestogens in medical therapy. In WWTP effluents, androgens were still the dominant class accounting for 60% of total hormone concentrations, followed by progestogens (24%), and estrogens (16%). Androstenedione and testosterone were the main androgens detected in all effluents. High removal efficiency (91-100%) was found for androgens and progestogens compared with estrogens (67-80%), with biodegradation the major removal route in WWTPs. Different profiles of progestogens in the receiving rivers and WWTP effluents were observed, which could be explained by the discharge of a mixture of treated and untreated wastewater into the receiving rivers.