Dioxins are among the most toxic anthropogenic chemicals in the enviro
nment. 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 indicat
e that end points other than cancer are also of concern. A health risk
analysis scenario based on health effects of TCDD other than cancer i
s discussed and compared with the projected intake from 1 ppb TCDD in
soil.