Study on environmental estrogen pollution in Yangtze River (Nanjing section) by an in vivo bioassay

Estrogenic activities and main causative fractions in three representative sections of Yangtze River (Nanjing section) were determined. The results showed that significant vitellogenin (VTG) and 17beta-estradiol (E(2)) induction and gonad atrophy were observed. Estradiol equivalents of actual water samples from Jiangxinzhou section, Sanchahe section and Daqiao section were 0.3651, 0.1301 and 0.5060 ng L(-1), respectively. Polar contaminants were responsible for the estrogenic activities in Jiangxinzhou section and Daqiao section while mid-polar and nonpolar contaminants resulted in majority of the estrogenic activity in Sanchahe section. To Jiangxinzhou section, Sanchahe section and Daqiao section, good positive correlations between VTG and E(2) (the correlation coefficients were 0.737, 0.690 and 0.817, respectively) and good inverse correlations between VTG and gonado-somatic index (GSI; the correlation coefficients were -0.838, -0.540 and -0.794, respectively) were obtained, whereas the correlations between E(2) and GSI were relatively poor (the correlation coefficients were only -0.557, -0.620 and -0.509, respectively).