A national risk assessment for intersex in fish arising from steroid estrogens.

The occurrence of intersex fish is widespread in the rivers of England and Wales. The extent of intersex in fish populations is believed to be strongly linked to their exposure to steroid estrogens. The present study presents, to our knowledge, the first national, catchment-based risk assessment for steroid estrogens in the world.

The temporal and spatial variability of sediment transport and yields within the Bradford Beck catchment, West Yorkshire.

Recent EU directives have emphasised the need to understand and limit potential water quality problems within urban river systems. Under certain conditions sediments and contaminants derived from industrial and domestic waste and the urban surface may be expelled into urban rivers via the sewer and drainage system. These discharges may lead to water quality problems within urban catchments.