according to the environmental group, Friends of Earth ( f o e ) an ici factory in Middlesborough is the uk 's largest polluter of a group of chemicals, alkylphenols, that has been shown to change the sex of fish. Basing its polluters' list on Environment Agency figures, f o e continued to press the government to track pollution more com prehensively. "The Environment Agency only details pollution from the 1,500 largest factories," said f o e . "It does not detail releases from smaller factories, agriculture or sewage treatment works, which are all potentially large sources of hormone-disrupting chemicals."
Alkylphenols are used in industrial detergents. f o e cites studies that show that wild male Roach have been feminised. In other words, eggs have been found in their testes, with the worst effects being seen in the River Aire in Yorkshire. f o e contends the river is heavily polluted with alkylphenols.