Family of 75 different toxic chlorinated hydrocarbons formed as by-products in chemical reactions involving chlorine and hydrocarbons, usually at high temperatures. The "premier" and probably most toxic member of the dioxin family is 2,3,7,8-Tetrachlorodibenzo-p-dioxin. Though these compounds have relatively low vapor pressures and poor solubility in water, they cycle from aquatic environments--where they have been deposited from waste incineration, wood burning, pulp bleaching, smelting, etc.---into the atmosphere in a series of small steps, staying airborne, and atmospheric mobile, for short periods of time. Dioxins have been found in some organisms on all the earth's continents. [Miller Jr., G. Tyler. Living in the Environment. 9th ed. Wadsworth Publishing Company: New York; 2002.] [Environmental Pollution; v119; 151-161; 2002.] [Science; v313; 1555; 2006.]