In recent years, concerns have been raised that low concentrations of chemicals may alter the normal functions of the endocrine system, resulting in potentially significant adverse effects on growth, reproduction, and/or development. For domestic wastewater discharges to surface water bodies, estrogenic activity of effluents has been suggested by chemical analysis, biomarkers, and /or in vitro assays. Chemical Measurements. Using sensitive analytical techniques, natural or synthetic hormones and chemicals that mimic estrogen, have been detected in some domestic wastewater effluents and...