Abstract
Very few investigations of the concentrations of estrogens in the effluents of urban drainage systems and in the receiving river water in areas with few constructed sewerage systems have been conducted. In this study, the concentrations of estrogens in the effluents of an urban drainage system and an onsite wastewater treatment plant, and in the receiving river were monitored for six months. The concentrations of estrogens and 17β-estradiol (E2) were determined by enzyme-linked immunosorbent assay (ELISA). Most estrogens were present in the dissolved fraction of the effluents and the river water. E2, which exists in natural waters according to many reports, accounted for 24% of the estrogens and has concentrations of 4.7±3.0 ng·l-1 (n=6) and 8.6±5.8ng·l-1 (n=6) in the effluents of the urban drainage system and the onsite wastewater treatment plant, respectively. The concentrations of estrogens and E2 in the receiving river water were two to three times higher than upstream levels. In addition, the concentrations of ammonium and estrogens showed a very high correlation (r=0.986) in all samples, suggesting that the increase in the concentrations of estrogens in the receiving river water was due to the presence of human excrement in the urban drainage system.
