Now that we know Ukrainian presidential candidate Viktor Yuschenko has been victim of poisoning by dioxins, it is a good opportunity to know better this kind of compounds. A good starting point is Lewis A. Shadoff’s page, All You Wanted to Know about Dioxins. Another excellent source of information is EPA’s page, Dioxin and Related Compounds. The Frequently Asked Questions (FAQs) in this site are very instructive.