Abstract
Yeast estrogen screen (YES) has been used since 1996 as a bioassay to quantify activity in wastewater. Here we present a modification of YES to measure estrogenic activity in water. This modification, called yeast estrogen screen no extraction (YESne), is faster and easier than the common method. The modified method can detect 17Ξ²βestradiol equivalent concentrations down to 1.1βng/L. The median effective concentration value (EC50) is 1.2Eβ10. It detected average influent concentrations of 16.4 and 17.5βng/L of 17Ξ²βestradiol equivalent at four Lehigh Valley, Pennsylvania, USA, wastewater treatment plants on September 18 and October 23, 2008, respectively, and average effluent concentrations of 5.1 and 8.1βng/L of 17Ξ²βestradiol equivalent at the same plants on the two dates, respectively. Reduction in 17Ξ²βestradiol equivalent activity for the four wastewater treatment plants averaged 67.8 and 52.3%, respectively, for the September 18 and October 23 samples. The YESne is a simple, quick method for quantifying estrogenic activity that has been used successfully in nonmajor undergraduate classes and could be adapted by wastewater treatment plant laboratory technicians to measure influent and effluent estrogenicity on a regular basis. This practice will greatly increase our knowledge base of estrogenicity in wastewater before and after treatment. Environ. Toxicol. Chem. 2011;30:2261β2269. Β© 2011 SETAC