Environmental assessment of estrogenic pollutants in Nam River of Korea using indirect competitive ELISA and E-screen assay

Abstract

Endocrine disrupting chemicals (EDCs) in ecosystem have raised a serious public health concern due to their potential adverse effects of interfering endogenous endocrine systems of organisms, including human being. Nam River is a main stream in southern part of Korea and has been used as a source of drinking water and for a variety of water-based activities of the people in this region. For the present study, water samples were collected from 11 different locations of Nam River, including two wastewater treatment plants (WWTPs). The collected water samples were analyzed with indirect competitive enzymelinked immunosorbent assay (IC-ELISA) and E-screen assay for the quantitative measurement of estrogens and the evaluation of their estrogenic activities, respectively. IC-ELISA showed that significant levels of estrogens (as estrogen equivalent concentration (EEC)) were present in WWTPs influents (5.537 ng-EEC/L for Jinju WWTP and 16.817 ng-EEC/L for Gyeongsang national university WWTP, respectively), but not detected in other river water samples. E-screen assay also showed similar results of the high estrogenic activities in WWTP influents. Unlike IC-ELISA, however, the results of E-screen revealed the presence of some weak estrogenic activities in all of the environmental water samples other than WWTP. One of the possible reasons of the difference is the presence of some estrogenic pollutants which are structurally unrelated to estrogens. From this, it is considered that the IC-ELISA method is a quick and reliable assay for the 1st-trial screening of large number of environmental samples with a relatively low cost. The present study could be helpful for the assessment of estrogen pollutants in environmental samples.