Dioxins have been studied more than any other chemical. It has been found to be toxic to all of the animals tested. However, the assumption that these tests can be extrapolated to humans is hotly contested. In this context the Monsanto and BASF studies were used to support the case that effects on humans were quite different to the effects being observed in laboratory animals. Michael Fumento, who is associated with the conservative think tank, the Competitive Enterprise Institute, argues in his book Science Under Siege that:

The assumption that dioxin is the most deadly chemical created by man—an assumption that is taken by most people to mean 'most deadly to me'—would only be true if we weighed about a pound and were small stout-bodied, short-eared, nearly tailless domesticated rodents....

But let's say that you are not a guinea pig, but rather are considerably smaller and have a little stub of a tail. That is, you are a hamster. Well, in that case you could practically season your porridge with dioxin, because tested hamsters required a dose about 1,900 times as high as the guinea pigs' to kill half the test group....Rabbits, mice, and monkeys cluster somewhere in the middle... (Fumento 1993, pp. 100-1)

The reliance on animal experiments was necessitated by the inability to experiment on humans, which was thought by most to be unethical. Although this did not stop Dow from doing experiments on prisoners at a Pennsylvania prison in 1965, applying dioxin to their skin and observing that they developed chloracne. No follow up was done on these prisoners (Gibbs & CCHW 1995, pp.8-9). Apart from these dubious experiments, the only human data available is where humans have been exposed to large doses of dioxin through their occupation or by accident and these are the people whom most human studies concentrate on.

...back to top

---

Additional Material:

Gibbs, Lois Marie and The Citizens Clearinghouse for Hazardous Waste, 1995, Dying from Dioxin (Boston, MA: South End Press).

Fumento, Michael, 1993, Science Under Siege: Balancing Technology and the Environment (New York: William Morrow and Co).