Impact of climate change and population growth on a risk assessment for endocrine disruption in fish due to steroid estrogens in England and Wales

In England and Wales, steroid estrogens: estrone, estradiol and ethinylestradiol have previously been identified as the main chemicals causing endocrine disruption in male fish. A national risk assessment is already available for intersex in fish arising from estrogens under current flow conditions. This study presents, to our knowledge, the first set of national catchment-based risk assessments for steroid estrogen under future scenarios. The river flows and temperatures were perturbed using three climate change scenarios (ranging from relatively dry to wet). The effects of demographic changes on estrogen consumption and human population served by sewage treatment works were also included. Compared to the current situation, the results indicated increased future risk:the percentage of high risk category sites, where endocrine disruption is more likely to occur, increased. These increases were mainly caused by changes in human population. This study provides regulators with valuable information to prepare for this potential increased risk. - Highlights: • Risk assessment for the 2050's including climate change and population changes. • Three climate scenarios considered (changes in river flow and river temperature). • Increased risk from fish intersex across all scenarios in England and Wales. • Population is the main factor causing the risk increase for the 2050's. - The predicted increase in risk of endocrine disruption in fish due to steroid estrogens in England and Wales in the 2050's is mainly due to human population increase rather than climate change