Dioxin and human health Essay Example | Topics and Well Written Essays - 500 words

Dioxin and human health - Essay Example The producibility is relatively high in presence of a catalyst like iron. Chemistry of Dioxins Para-dibenzodioxins are formed when two oxygens combines two benzenes (or chlorinated benzenes). The number of isomers is several as both could have upto 8 chlorines – 75 for PCCDs and 135 for PCDFs. These compounds are called as congeners. Toxicity is expressed as Toxic Equivalent Factor (TEF) and toxicity is based on 2,3,7,8 TCCD which is expressed as TEF. The toxicity is caused because of the four chlorine atoms at positions 2, 3, 7, 8 on the dioxin molecules. The toxicity is expressed as pg TEQ/g lipid (ppt) and is summed up based upon their toxicity equivalent concentrations. OCCD is the most abundant isomer related to human contamination followed by the 2,3,7,8 substituted hepta and hexa-chloro congeners. 2,3,7,8 TCCD is normally less abundant than PCCD. The activation of Ah receptor determines the TEF. The oxygen bond between the two benzenes could be substituted to sulphur or azide. Chlorine could be replaced by bromine. Effect of Dioxins on Human Health Eating, breathing, and polluted air and skin contact with contaminated soil and materials are the major routes for human exposure. The PCCDs reach the blood stream after passing from the gastrointestinal tract and eating food containing the PCCDs.