They want the Government to insist that the chemical industry limits or ceases altogether its use of chlorine-based compounds, including dioxins.
On Tuesday, the American Environmental Protection Agency (EPA) published 2,000 pages of draft results from a three-year dioxin study by more than 100 scientists - the most exhaustive review of a single compound the agency has undertaken.
The EPA said dioxins were a potential cause of a range of illnesses including developmental, reproductive, hormonal and immune system problems, even at very low exposure levels. These include physical and mental development problems in children and falling sperm counts in men, scientists involved in the study said yesterday. The review also re-affirmed evidence that dioxins are linked with cancer in humans.
People are exposed to dioxins largely through food contaminated with airborne dioxins that settle on plants. Most of these come from industrial waste incinerators.
Claude Hughes, a dioxin expert from Duke University, North Carolina, was one of about 30 scientists asked to review the EPA's study.
At a London press conference yesterday he said dioxins were a danger to human health and fertility. He said the dioxin levels seen in people are now at the level known to cause serious problems in animals.