Fractionation Method for Estimating the Cause of Estrogen-like Activity in Sewage

It has been reported that estrogen-like activities have been detected in sewage around the country. However, earlier reports have merely suggested the existence of unidentified estrogen-like activities based on comparisons of the results of chemical analysis and bioassay, and there have been few examinations regarding unidentified estrogen-like activities.In this paper, therefore, we examined the polarity distribution of estrogen-like activities in order to clearly identify the sources of estrogen-like activities found in sewage. Since unidentified estrogen-like activities may be caused by the mutual effect of estrogen-like substances, we also examined the mutual effect between principal estrogen-like substances and between fractionated samples. We also examined the effect of impurities that may hinder estimation of the sources of estrogen-like activities, and conducted comprehensive examinations of the sources of estrogen-like activities found in sewage.The results of measuring polarity-fractionated influent sewage, using the recombinant yeast method, have verified that estrogen-like activities are widely detected in the low to high polarity range. We also estimated, based on the results of chemical analysis, the contribution of each substance to the estrogen-like activities, and found that unidentified estrogen-like activities that cannot be explained by estron (E1), 17β-estradiol (E2) and Nonylphenol (NP) exist in estrogen fractions.The verification test of the mutual effect between fractionated samples, and found a synergistic reaction when a specific fraction was added. This fraction, however, also showed cytotoxicity to the yeast. We therefore examined estrogen-like substances and cytotoxic substances in this fraction, and found that the estrogen-like activities are overestimated in the presence of Liner ArkileBenzen Solfonate (LAS) with no estrogen-like activity. This means that samples with high LAS concentration must go through separation and quantification.