EMSG38: Review of the Relative Contribution of Industrial Chemicals, Compared to Steroids, in Causing the Sexual Disruption in Wild Fish Populations

Description

Steroidal estrogens, originating principally from human excretion, are likely to play a major role in causing widespread endocrine disruption in wild populations of the roach (Rutilus rutilus), a common cyprinid fish, in rivers contaminated by treated sewage effluents. Given the extent of this problem, risk assessment models are needed to predict the location and severity of endocrine disruption in river catchments and to identify areas where regulation of sewage discharges to remove these contaminants is necessary. This study attempted to correlate the extent of endocrine disruption in roach in British rivers, with their predicted exposure to steroid estrogens derivedfrom the human population. No correlation was found between any of the end points measured in the roach and the proportion of industrial effluents entering the rivers we studied. Overall, the results provide further and substantive evidence to support the hypothesis that steroidal estrogens play a major role in causing intersex in wild freshwater fish in rivers in theUnited Kingdom and clearly show that the location and severity of these endocrine-disrupting effects can be predicted.