Dioxin is not manufactured intentionally. They form as an unintended contaminant or by- product during combustion or during the manufacture of certain chlorinated chemicals.

Dioxins and furans can be produced when almost anything is burned under the right conditions. Two major sources are municipal waste and hospital incinerators, though emissions from these sources have been reduced in recent years because so many of these incinerators have shut down in recent years in many cases due to opposition from local grassroots community based organizations. Bleaching wood pulp with chlorine to make paper white has been another major source. Dioxin is found in the waste water released from these plants, although the amounts have declined because many plants have converted to processes that use less chlorine.PCBs were used as insulators in electrical equipment, but their production was banned in 1977. Today, they remain in use mostly in electrical transformers and capacitors, especially in large office or apartment buildings.PCBs are commonly found in river sediment nears plants where PCBs were generated or used.

Dioxin is a highly persistent chemical that only slowly degrades in the environment. Dioxin present in surface soil may take from 9 to 15 years to degrade to half its concentration. In subsurface soil, dioxin will remain largely unchanged with time. Dioxin in water settles in sediment and can re-enter the water when the sediment are disturbed.

Dioxin goes into the air and people breathe in the particles. But a bigger problem is that the particles settle on grazing land where cows eat the grass and the dioxin gets concentrated in the fat in their meat and milk.It also gets concentrated in cattle and hogs that are fed dioxin- tainted grain.Dioxin particles can also fall directly into rivers, streams, and other bodies of water or reach these waterways in surface water runoff. Dioxin settles on the bottom where fish and shellfish ingest small particles of sediment. Dioxin then builds up in their fat or organs. In Maine, pregnant women are advised not to eat the green "guts" in lobsters because it's high in dioxin. People call it the "tomalley," but it's actually a combined liver and pancreas - a hepatopancreas.

Yes. More than 90 percent of our exposure comes from food, mostly fish, meat, poultry, and non-skim dairy products. Fattier fish have more dioxin than leaner fish. Shellfish like lobsters are low in fat, but the dioxin may be in their hepatopancreas or organs, not the meat.

Yes. Dioxin slowly accumulates in the body. The average levels of dioxin in the U.S. population is about 25 parts per trillion (ppt) according to the US Environmental Protection Agency (EPA). Approximately 10% of the population may have tissue levels has much as 3 times higher than this level.

The USEPA has found that the body burden level of dioxin in animal studies can be relate to adverse health effects observed in both animals and people.They have also found that the average level of dioxin found in the general US population is very close to these levels. EPA interprets this to mean that there is little or no "margin of exposure" left for most people. We see this as meaning that we are nearly "full" and that any additional exposure of dioxin can result in adverse health effects. Some people already have body burden levels that are above the average and they are likely already suffering adverse health effects.

Yes. Nursing infants, some workers, people who eat fish as a main staple of their diet, such as indigenous people and fishermen, and people who live near dioxin release sources are at greater risk of developing adverse health effects from dioxin because they are exposed to higher concentrations.

Yes, but not easily. There's a general process within the body of accumulation and removal of toxic substances. Dioxin is accumulated in fat which is hard to get rid of. If you lose weight, you lose some dioxin with the fat. If you're breastfeeding, you get rid of it through the breast milk. Infants get their greatest dose of dioxin during breastfeeding because it's concentrated in breast milk and because the infant is so small that the dose per pound of body weight is quite high. The benefits of breastfeeding still outweigh the risks of dioxin, though we'd rather not have to make such a choice.

Dioxin's "half-life" in the human body is about seven years. In other words, it takes about seven years for half of the dioxin in your body to be removed and then another seven years for the half of that amount and so on. This means your body will never be free of dioxin contamination.

Exposure to dioxin can lead to a wide array of adverse health effects including cancer, birth defects, diabetes, learning and developmental delays, endometriosis, and immune system abnormalities.

Dioxin binds very strongly to intracellular receptors in the nuclei of animal and human cells throughout the body. So dioxin can easily get into the nucleus, where the cell's DNA is located, and wreak havoc. If it damages the DNA, that could cause cancer or birth defects. It could also alter the DNA's instructions to make normal enzymes, hormones, and other proteins, which could lead to any of a number of diseases.

Yes. Dioxin is a known carcinogen. TCDD is the most potent animal carcinogen ever tested. It causes tumors in both genders of every species and every strain of animal that's been tested. And the animals get different types of tumors, so it doesn't just initiate tumors, it also promotes the growth of tumors caused by other chemical initiators.

Yes. Everyone, except perhaps some industry groups, accepts that dioxin is a human carcinogen.IARC, the International Agency for Research on Cancer, which is part of the World Health Organization (WHO), reclassified it as a human carcinogen in 1997. In January 2001, the Department of Human Health and Services' National Toxicology Program classified dioxin as a known human carcinogen. The September 2000 draft of the USEPA's Health Assessment document on dioxin also classifies dioxin as a known human carcinogen.

It is the most potent substance ever tested by the USEPA or by any private or government research center. Dioxin causes cancer in multiple species in multiple organs in both sexes. Cancer in animals has resulted from exposures as low as 200 ppt.

The USEPA released a draft report last fall that projected an excess cancer risk of one in 100 for the most sensitive people who consume a diet high in animal fats. In other words, the risk of getting cancer from dioxin - over and above the risk of cancer from other sources - is one in 100 for some people. This is a worst-case scenario. It's for the most sensitive people among the five percent of the population who consume the most dioxin. Scientists refer to this as the "upper bound estimate." This is a shocking estimate.EPA's upper bound risk for the most sensitive people to average exposure is one in 1,000 which is also a serious risk level. A general "acceptable" risk level is one-in-one-million.Some people may be exposed to little if any dioxin.

The USEPA released a draft report last fall that projected an excess cancer risk of one in 100 for the most sensitive people who consume a diet high in animal fats. In other words, the risk of getting cancer from dioxin - over and above the risk of cancer from other sources - is one in 100 for some people. This is a worst-case scenario. It's for the most sensitive people among the five percent of the population who consume the most dioxin. Scientists refer to this as the "upper bound estimate." This is a shocking estimate.EPA's upper bound risk for the most sensitive people to average exposure is one in 1,000 which is also a serious risk level. A general "acceptable" risk level is one-in-one-million.Some people may be exposed to little if any dioxin.

They're the most reliable ones we have. Several scientific peer review groups, including the agency's Scientific Advisory Board, which includes consultants outside of the agency have approved the agency's report including the methods EPA used to make their risk estimates.

Most of the studies of exposed populations indicate that dioxin causes an increased risk of all cancers. Some studies suggest that it promotes lung cancer and soft-tissue sarcomas, which are cancers of the fat and muscle. Most studies don't focus on any one type of cancer because there are so few individual cancers in small studies of exposed populations.

Dioxin exposure is linked to skin rashes, liver disorders, reproductive problems, birth defects, learning and developmental delays, endometriosis, immune system abnormalities, and diabetes.