MORE INFORMATION IARC evaluates carcinogenic risk associated with dioxins (Issued 14 February 1997)

Contrary to industry claims that chloracne is the only result of dioxin exposure, mounting evidence caused the World Health Organisation in February 1997 to declare dioxin a Class 1 Human Carcinogen. The International Agency for Research on Cancer (IARC), a part of the World Health Organisation, formed a working group to review all the published scientific data and concluded that based on human and animal evidence, TCDD does cause cancer in humans.

The United States Environment Protection Agency's draft reassessment of dioxins (1994) has estimated that current background exposures may result in upper bound population cancer risk estimates in the range of one in ten thousand to 1 in a thousand attributable to exposure to dioxin and related compounds. However, they also state that exposure to high levels of dioxins at an early stage in life may underestimate such cancer risk levels if exposure in the womb is important in the ultimate carcinogenic outcome.