Toxicological Trivia from February 03, 2010: Dioxins are considered by several specialized agencies as the most toxic and dangerous chemical substance known. Among the possible risks to human health underlines its long-term relationship with various types of cancer, and various reproductive, fertility  and vascular problems. The are known more than 400 different compounds from this family, but just how many of them have able to demonstrate its toxicity to humans:
a) 3;
b) 30;
c) 300.

Correct Answer b. Read in Spanish news: About  dioxins. See also related trivia # 64: dioxins in inspired air, and # 65 dioxin congeners.