What are dioxins?
Dioxins are a group of aromatic substances whose essential core is 1.10-dioxantraceno also called “dibenzo-p-dioxin.” The best known are the chlorinated derivatives, with the reference tetrachlorodibenzo-p-dioxin (TCDD). Also found in brominated versions when chlorine is replaced by bromine (bromodibenzo-p-dioxins and bromodibenzofuranos BDD BDF). There are other chemically related to environmental and human toxicity, the cloridibenzofuranos (CDF) and polychlorinated biphenyls (PCBs).
Where do dioxins?
Dioxins are formed during combustion processes such as incineration of wastes such as wood, coal, oil and others. They are also produced events such as forest fires, volcanic eruptions. The use of chlorine in the bleaching process of paper pulp is another source of dioxins. Cement and mineral extraction are the source of these substances. Cigarettes also create small amounts of dioxin.
Do all dioxin are dangerous?
Of the nearly 25 varieties of dibenzodioxins (BDD) and dibenzofurans (BDF) and its equivalent retardants are 7 varieties that develop toxic effects. Of these highlights presented by the chlorine atoms in positions 2,3,7 and 8. There are about 135 compounds for policloribifenilos cloridenzofurnaos and 10 of which manifest toxic dioxin, especially those with 4 or more chlorine atoms.
Why create so much concern dioxins?
Dioxins can cause various health effects. These depend on:
* the level of dioxin exposure
* When was the exposure
* the duration of exposure
* the frequency of exposure.
Also depend on the stage of life when there was contact with dioxin: fetus, pregnancy, children, adults, older adults.
In people undergoing major exhibitions of dioxins observed chloracne, a skin lesion that appears similar to acne on the face and upper body. You can also see redness, skin discoloration, hair loss and liver damage.
A major concern is related to the development of cancers. Animal studies have shown an increased cancer risk when exposed for a long time to dioxins. Cancers that have more to do with dioxin exposure are cancer of the breast in women and prostate in men. There is also concern that the intake of dioxins can cause alterations in fetal development during the reproductive stage. Dioxins pass the placenta and affect the fetus during pregnancy, especially the brain and hormone-sensitive issues such as love. Also damage the immune system and interfere with the hormonal system.
Do you produce dioxin cancer?
Yes, the agency for the U.S. Environmental (EPA) reported that these substances pose a risk to the development of cancer in humans. In February 1997, announced that 2, 3, 7,8-TCDD was more carcinogenic dioxin classified as type I, ie, with sufficient scientific evidence to show that condition. This was endorsed in 2001 by the National Toxicology Program of the United States (1.2)
what is the environmental cycle of dioxin?
These compounds are chemically stable, especially those with 4 or more chlorine atoms. Once produced over long distances large polluting industries. Decompose in the presence of sunlight, but may persist for decades in the layers of soil exposed to sunlight. Brominated derivatives are substantially easier to photodegrade (degrade light) chlorinated compounds. When water is delivered to the set in sediments and plants, which are eaten by fish deposited in fatty tissues. If they are released into the air, small amounts can be inhaled by the living. If they fall to the ground, can occur by contact absorption through the skin. They are also ingested in food. Once produced these substances because they are very lipophilic (affinity for fat) in animals and humans.