Evaluating variation of estrogenic effect by drinking water chlorination with the MVLN assay

Abstract

It is important to evaluate the estrogenic effect of disinfection by-products in drinking water in addition to typical possible endocrine disrupting chemicals. The estrogenic effect was measured by the MVLN assay as an estrogen receptor transcriptional activation assay. The results suggested that the isolation procedure of aquatic humic substances using XAD7HP resin can be recommended to detect the estrogenic effect of natural water and its chlorinated drinking water by the MVLN assay. Sample volume necessary for the assay would be 1.2 L and required concentation factor would be 100 times. The relative importance of organic substances in Lake Biwa water and the chlorinated one concentrated using XAD7HP resin is large in terms of estrogenic effect. It was also suggested that 4-nonyl phenol and 17 β-estradiol would be important chemicals in investigating the estrogenic effect of natural water. The estrogenic effect of Lake Biwa water increased by chlorination. The estrogenic effect of chlorinated water was approximately 2.3 times as strong as that of Lake Biwa water itself.