Up to 60 per cent of male fish in some British rivers have developed
significant female characteristics because of chemicals in effluent that mimic
the hormone oestrogen, a study commissioned by the Environment Agency suggests.
Researchers from Brunel University found a direct correlation between the
concentration of sewage in rivers and the severity of feminisation in male
roach—including eggs in the testes.
More from New Scientist
Explore the latest news, articles and features
Popular articles
Trending New Scientist articles
1
The world's fastest spider tops 3.5 metres per second
2
Babies are born with the neural foundations for maths
3
Where, when and how to watch the 2026 solar eclipse
4
A type of fibre that stimulates GLP-1 release approved for use in food
5
The best new science-fiction novels published in July 2026
6
The weirdness of neutrinos could completely rewrite particle physics
7
Slowdown of AMOC ocean current may be gradual and reversible
8
US government wants to have a useful quantum computer by 2028
9
We’re not the most successful human species
10
I’m the first person whose life was saved by CRISPR base editing



