- What is dioxin?
Dioxin is a group of similar, highly toxic organic chemicals that are created as an unintended by-product of incomplete combustion, or as a contaminant in chemical manufacturing processes.
- Why should we be concerned with dioxin in our environment?
Dioxin is one of the most toxic chemicals known to man. On November 2, 2000, the US Environmental Protection Agency’s (EPA’s) Science Advisory Board (SAB) approved the science supporting the findings of its Draft Dioxin Reassessment. The findings concluded that dioxin is a potent animal toxicant with the potential to produce a broad range of adverse effects in humans including reproductive effects, developmental effects, suppression of the immune system and cancer; and that the amount of dioxin found in the bodies of members of the general population (body burden) closely approaches the levels at which adverse effects are expected to occur. EPA estimates cancer risks for the general population to be in the range of 1-in-100 to 1-in-1,000. This is 3 to 30 times higher than previously thought. The most toxic dioxin compound, 2,3,7,8-TCDD, has recently been upgraded to a known human carcinogen by the US Department of Health and Human Services. Dioxin has also been shown to have similar adverse effects on wildlife such as birds, fish and mammals.
- How are people exposed to dioxin?
Much like mercury, dioxin is released into the environment in very small quantities. Most dioxin is released into the air, where it can travel thousands of miles before being deposited on the earth’s surface. As a result, dioxin deposited in New Hampshire comes not only from local sources, but also from emissions of sources far upwind. It builds up in soils, sediments and plants, bioaccumulates in animal and fish tissue, and passes up the food chain to people. It is estimated that most people’s exposure to dioxin occurs through the diet, with more than 95 percent coming from the intake of animal fat and dairy products.
- What are the major sources of dioxin in New Hampshire?
Almost all dioxin released to the environment in New Hampshire is created as an inadvertent by-product of the combustion of various materials. The New Hampshire Dioxin Reduction Strategy estimates that over 80percent of dioxin emissions to the environment in New Hampshire are emitted from 5 source categories. The sources and their estimated contributions are presented below:
- medical waste incinerators, (29%)
- wood-fired boilers, (20%)
- backyard burning of household waste, (17%)
- residential wood combustion (10%), and
- mobile source fuel combustion (8%).
- What is DES doing to reduce dioxin emissions in New Hampshire?
The Strategy makes over 50 recommendations to reduce dioxin from New Hampshire sources. It recommends prompt action from two source categories; backyard trash burning and medical waste incineration. By addressing these two sources, DES estimates that almost a 50 percent reduction in dioxin emissions can be achieved in the next two years. Other recommendations in the strategy focus on source reductions primarily through pollution prevention, public education, energy efficiency and conservation. These are expected to result in further substantial reductions in dioxin exposure for New Hampshire citizens. The Strategy also recommends more study of certain source categories such as wood fired boilers, and if these studies show that reductions from these sources are feasible, DES will then return to the legislature with appropriate recommendations.
By taking the initiative in reducing our own dioxin emissions, New Hampshire can insist on similar reductions of dioxin from upwind regions, thus significantly reducing the public health and ecological threat of dioxin contamination in our environment.
Dioxin and the New Hampshire Dioxin Reduction Strategy