Dioxins, the highly toxic chemicals produced by waste incineration and industrial processes which tests have shown to be lingering in the bodies of people all over the planet, have been identified as the cause of many cancers in a new report from the US Environmental Protection Agency.
A draft of the EPA report, leaked yesterday to the Washington Post, has taken the US by surprise and is likely to send shockwaves throughout the rest of the world, forcing an upgrade in the assessment of the hazard posed by dioxins. It had been thought that the risk was diminishing because levels of the chemicals in the environment were dropping.
The report will fuel mounting opposition in communities across Britain to a new generation of up to 160 major waste incinerators that the government is expected to encourage over the next 20 years.
Dioxins are chemical compounds unintentionally released by incinerators burning sewage sludge and household, hazardous and medical waste. They are also released in industrial processes such as steel making.
Among the most poisonous man-made chemicals, they accumulate in fat and milk and work their way up the food chain. Even low-level exposure is known to interfere with the immune, reproductive and endocrine systems. The latter is involved in the secretion of hormones. Dioxins also effect the early growth and development of humans and animals.
By far the greatest dioxin producer in Britain, according to the Environment Agency, is British Steel, whose works at Llanwern, Port Talbot, Scunthorpe and Teesside pump out almost as many dioxins as the next 15 most polluting companies.
That dioxins are already widely present in the environment and food supplies of all industrialised countries is well-known, but evidence has been slowly accumulating about how widespread and carcinogenic some are. Yesterday's EPA report is remarkably similar to a more low key report from a group of German scientists, which last year concluded that dioxins might be responsible for 12% of human cancers in industrialised countries.
The British government is gradually accepting that dioxins pose real health threats.
In 1994, the Department of Health published a report saying that "despite insufficient evidence for clear causal links", it would be prudent to regard dioxins as possible human carcinogens".
The proposed incineration plants will be needed, it is claimed, to handle the growing mountains of household waste that the EU is banning from landfill sites. In response to the EU directive, the government is expected to announce that by 2020 it will recycle a third of household waste and burn a third.
Some communities are already arguing that these incinerators will pose a health hazard and that money should be spent on more expensive recycling and composting schemes.
Such alternatives, say Friends of the Earth, would be popular, provide more jobs and be easy for people to understand. They say that £250m collected yearly in waste tax could be used to build new recycling centres.
Chris Pilbury, who works with a coalition of 25 community groups in north-east Wales that oppose a massive proposed incinerator and cement kiln expansion scheme near Wrexham, said: "People will not tolerate these risks. Feelings are running high and this report con firms that we are right to to be concerned."
The document, nine years in preparation, says that for those who eat large amounts of fatty meat and dairy produce the risk - on top of any others they may be exposed to - of getting cancer could be as high as one in 100.
Yesterday the EPA said that at least one scientist involved disputed the statistic and that there was a possibility it would be amended before official publication in June. But there will be no dilution of the message of acute concern about dioxins in the report, which for the first time names the most toxic of the group, TCDD (the infamous Agent Orange of Vietnam) as a human carcinogen.
In 1997, the International Agency for Research on Cancer (IARC) categorised TCDD as a "known human carcinogen" after analysing the epidemiological evid