Page 991 - The Toxicology of Fishes

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Estrogenic Effects of Treated Sewage Effluent on Fish:

Steroids and Surfactants in English Rivers

Charles R. Tyler, Edwin J. Routledge, and Ronny van Aerle

CONTENTS
Introduction: How Estrogenic Activity in Sewage Treatment Works Effluents
Was First Discovered ...................................................................................................................971
Estrogenic Activity in English Rivers ...................................................................................................974
Widespread Sexual Disruption in Wild Fish in English Rivers............................................................976
Identification of Estrogenic Substances in STW Effluent and Evidence That
They Cause Feminization of Fish in English Rivers...................................................................982
Natural and Synthetic Steroidal Estrogens............................................................................................985
Concentrations in Effluents and Rivers .......................................................................................985
Estrogenic Activity in Fish ..........................................................................................................986
Alkylphenolic Chemicals.......................................................................................................................987
Concentrations in Effluents and Rivers .......................................................................................987
Estrogenic Activity in Fish ..........................................................................................................990
Mixtures Effects.....................................................................................................................................992
The Dimension of the Estrogenic Problem in U.K. Rivers..................................................................992
Conclusions............................................................................................................................................993
Acknowledgments..................................................................................................................................995
References..............................................................................................................................................995

Introduction: How Estrogenic Activity in Sewage
Treatment Works Effluents Was First Discovered

It was more than 25 years ago that sexual disruption in fish was first reported in fish in the River Lea
catchment, Southeast England. Thames Water Authority staff, acting on casual observations by anglers,
found a low incidence (around 5%) of intersex, or hermaphroditism, in populations of wild roach (Rutilus
rutilus), a common lowland freshwater cyprinid, living in a sewage effluent settlement lagoon and in
the river just downstream from a sewage treatment works (STW) effluent discharge (Sweeting, 1981).
This finding was deemed very unusual because roach are gonochoristic (they have either a testis or an
ovary), and hermaphrodites are believed to be very uncommon in this species (Jafri and Ensor, 1979;
Schultz, 1996). The presence of intersex roach at the sites in question raised the possibility that
compounds in STW effluent might cause disruption in sexual development. Quite independently, in the
mid-1980s, while conducting studies on the endocrine control of reproduction in captive rainbow trout,
our research, together with the U.K. Ministry of Agriculture, Fisheries, and Food (now called the
Department of the Environment, Food, and Rural Affairs), discovered that the plasma of male fish
contained measurable amounts of vitellogenin (VTG). VTG is normally synthesized by the liver in
female oviparous (egg-laying) vertebrates in response to estrogen and is sequestered by developing

971