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

Williams, Richard J.; Keller, Virginie D. J.; Johnson, Andrew C.; Young, Andrew R.; Holmes, Matthew G. R.; Wells, Claire; Gross-Sorokin, Melanie; Benstead, Rachel. 2009 A national risk assessment for intersex in fish arising from steroid estrogens. Environmental Toxicology and Chemistry, 28 (1). 220-230.

Full text not available from this repository.


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 oestrogens. This paper presents the first national, catchment-based, risk assessment for steroid oestrogens in the world. A Graphical Information System-based model predicted the concentrations of estradiol (E2), estrone (E1) and ethinylestradiol (EE2) which were combined and compared with known biological effect levels to predict endocrine disruption risk for 10,313 individual river reaches (21,452 km) receiving effluent from more than 2,000 sewage treatment plants (STPs) serving over 29 million people. The large scale of this assessment underlines the usefulness of computer based risk assessment methods. Overall, 39% of the modelled reaches (all percentages are expressed as % of the total river length modelled) in England and Wales were predicted to be not at risk from endocrine disruption (mean concentrations <1 ng/L E2 equivalents). There was a large range in the percentage of river reaches at risk in the various regions from 5% in Wales to 67% in the Thames catchment. Important factors influencing this proportion are the population density, particularly their location and the available dilution. A very small proportion of reaches, approximately 1 to 3% were predicted to be at high risk (>10 ng/L E2 equivalents). However, many of these high risk reaches were ditches which were composed almost entirely of sewage effluent. The model could equally well be applied to any other chemical of concern emanating from the human population and which would be impracticable to assess by measurement.

Item Type: Publication - Article
Digital Object Identifier (DOI):
Programmes: CEH Programmes pre-2009 publications > Water > WA03 Developing strategic data and knowledge at a catchment scale to enable the wiser management of the water environment
UKCEH and CEH Sections/Science Areas: Acreman
Boorman (to September 2014)
ISSN: 0730-7268
Additional Keywords: Oestrogen, Catchment, Risk assessment, Modelling, GIS
NORA Subject Terms: Ecology and Environment
Date made live: 04 Feb 2009 15:38 +0 (UTC)

Actions (login required)

View Item View Item

Document Downloads

Downloads for past 30 days

Downloads per month over past year

More statistics for this item...