Analysis of estrogenic activity in environmental waters in Rio de Janeiro state (Brazil) using the yeast estrogen screen

• Monitoring of the estrogenic activity (EA) in Paraíba do Sul river was performed.
• Estrogenic activity was detected in river water and treated water supplied to the public.
• Ozonation and chlorination removed EA caused by hormones and Bisphenol A.
• Combination of ozonation and chlorination reduced EA using low doses of oxidants.

The estrogenicity of waters collected from an important hydrological system in Brazil (Paraiba do Sul and Guandu Rivers) was assessed using the yeast estrogen screen (YES) assay. Sampling was performed in rivers and at the outlets of conventional water treatment plants (WTP). The removal of estrogenic activity by ozonation and chlorination after conventional water treatment (clarification and sand filtration) was investigated employing samples of the Guandu River spiked with estrogens and bisphenol A (BPA). The results revealed a preoccupying incidence of estrogenic activity at levels higher than 1 ng L−1 along some points of the rivers. Another matter of concern was the number of samples from WTPs presenting estrogenicity surpassing 1 ng L−1. The oxidation techniques (ozonation and chlorination) were effective for the removal of estrogenic activity and the combination of both techniques led to good results using less amounts of oxidants.