Resources Glossary of Terms About Reflect Act Create Investigate Connecting The Coast Home Page Investigate


What is Dioxin and why is it part of the Nasty 9?

Three of the Nasty 9 critical pollutants belong to the family of chemicals called "dioxin." There are a total of 210 possible forms of dioxin, with varying degrees of toxicity to humans.

leader poisoned by dioxinDioxin is a suspected carcinogen (cancer causing agent) which is toxic to the immune system and may have negatively affect human reproduction and development. In humans, dioxin has been shown to cause chloracne, an acne-like skin disorder caused by prolonged exposure to chlorinated hydrocarbons and liver damage.

Ukrainian opposition leader Viktor Yushchenko, after being purposely poisoned by his opponents with dioxin, showed symptoms of chloracne.

Because of its high level of toxicity and its ability to bioaccumulate in the environment, dioxin is a member of the Nasty 9 and a target for Zero Discharge to totally eliminate it from the Lake Superior Basin.

Where Does Dioxin Come From?

Unlike mercury or PCBs, dioxin is not manufactured nor does it exist naturally. So, where does it come from?

Dioxins are produced only as by-product from burning (combustion) and chlorination processes used in the paper making industry.

Hexachlorobenzene (HBC) and Octachlorastyrene (OCS) and can also be released when household waters are burned in a burning barrel where lower burning temperatures do not allow for materials to be completely incinerated. These chemicals are also created as a manufacturing by-product and used as pesticides.

Industrial Sources of Dioxi.

We usually point to big industries as the bad guys who cause critical pollutants getting into our environment. Most of the industrial sources of dioxin emission within the Lake Superior Basin have been closed. Industrial sources that once contributed dioxin to the environment through manufacturing processes that used combustion or chlorination included:

ore processing facility
Ore processing plant at Wawa, Ontario, was once a source of dioxin emissions.

Ore-Processing Facilities
The ore processing facilities at the Algoma Ore Division iron sintering plant in Wawa, Ontario and the White Pine Mine smelter in Michigan's Upper Peninsula were once sources of dioxin produced from their combustion activities. Both facilities are now closed.

Medical Waste Incinerators
Medical waste incinerators in both the US and Canada which once contributed to dioxin emissions have been phased out. The disposal of fly ash from the incineration of medical wastes remains a potential source of dioxin.


Paper Mill - International Falls, MN

Paper Mills
Dioxin produced in the paper mill chlorination from the paper mills in the Thunder Bay Region have declined.

The closure of these industrial sources have resulted in a very large reduction in dioxin emissions within the Lake Superior Basin from industrial sources.

However, dioxins remain in Lake Superior water and sediments.





cartoon: enemy is usSo where is dioxin coming from now?

As of 1999, all small community incinerators are assumed to be closed in the U.S. portion of the Basin.

Today most of the dioxin released to the atmosphere is produced by citizens using small incinerators and burning barrels used at homes at nursing homes, schools, and businesses like grocery stores.

smoking barrel
Do the math...burning barrels are a potentially significant source of dioxin and other toxic emissions.

Many homes, especially in rural areas, use a backyard burning barrel or small indoor incinerator to burn up household trash. Isn't it a cheap way to get rid of rubbish, especially if you have to pay for disposing of your household garbage?

WRONG! That harmless burning barrel behind your home may be exposing you, your family, and the environment to more pollution than a big municipal incinerator. Household "burn barrels" are a significant dioxin source that can cost the health of your family and the environment.

Because burning barrel and home incinerator garbage fires burn at lower temperatures, they release up to 80 times more toxic pollutants into the air than a full-scale municipal incinerator, according to the U.S. Environmental Protection Agency.

Investigate the threat from backyard burning barrels

smoke stacksResearch estimates that it only takes as little as 1.5 to 4 households (depending on the amount each burns) burning their waste in the open, such as in burn barrels, to equal the dioxin generating potential of a fully-operational municipal waste disposal facility (Lemieux,1998).

The average person in the U.S. generates between 800 and 1,350 pounds of household waste in a year (1999). The U.S. EPA estimates that 40 percent of people living in non-metropolitan areas burn their waste and that 63 percent of their daily waste is burned in burn barrels. Nationally, this amounts to over 1.8 billions pound of household waste burned in burn barrels every year. Normalized for the U.S. Lake Superior Basin population, this amounts to over 4.5 million pounds of household waste openly burned in the Lake Superior Basin each year.

dioxin emmission chart

wood stacks
Wood treated with PCP and industrial sites contaminated with PCP are potential sources of dioxin.


Other Sources of Dioxin

The wood treatment chemical called "pentachlorophenol" (PCP) contains dioxin and hexachlorobenzene. Pentachlorophenol has been used to preserve a variety of commercial products, including textiles and leather goods in the United States and abroad.

In the past, pentachlorophenol was also widely used as a pesticide although most of those uses are now restricted.





Significant progress has already been made in closures of industrial sources such as paper mills using chlorination processes that create dioxins. Closures of industrial sources that produced dioxins through burning have also significantly reduced dioxin sources.

no burn logoThe good news is that we can do something about the largest remaining source of dioxin in the Lake Superior Basin by ELMINATING BURNING BARRELS. We can work with our neighbors and communities to do public education to understand the threat burning barrels pose to human health and the environment eliminate them.

Don't be fooled there is no "safe" household burning barrel.

The goal for the virtual elimination of all dioxin sources within the Lake Superior Basin:



TAKE THE NEXT STEPS... To Eliminate Dioxin in the Environment


man on beach CREATE... your own service learning experience to protect and restore aquatic communities. This section provides you with a template to get started in developing your own service learning project.
girl with net ACT... Take action to help restore and sustain aquatic communities and learn about what others are doing in the Lake Superior Basin and your community. This section will give you hands-on things you can do to help!
group reflects REFLECT.... Share and celebrate your experiences with others. This section lets you share what you learned with others.


Copyright 2007 - University of Wisconsin Extension
Comments and questions about this site may be directed to