UNDERNEWS: The daily news service of the Progressive Review, Washington's most unofficial source Furthermore, an investigation by the BBC's Country File and the Independent has revealed research, to be published this month, that shows that artificial oestrogens, used in contraceptive pills and emitted through sewage works, appear to be changing the sex of half the fish in Britain's lowland rivers. Scientists and environmentalists fear that the powerful chemicals are getting into drinking water and affecting human fertility. One third of Britain's drinking water comes from rivers; most of it is taken from below sewage works