Public health assessment for dioxins exposure from soil.

Dioxins are among the most toxic anthropogenic chemicals in the environment. Their toxicity has been extensively studied in both humans and animals. Dioxin-contaminated soil may result in dioxins occurring in a food chain. This is especially important for the general population. It has been estimated that about 98% of exposure to dioxins is through the oral route. In the 1980s, a concentration level of 1 ppb 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in soil was specified as "a level of concern," based on cancer effects. However, recent studies indicate that end points other than cancer are also of concern. A health risk analysis scenario based on health effects of TCDD other than cancer is discussed and compared with the projected intake from 1 ppb TCDD in soil.