The Department of Natural Resources says burning household trash and yard waste in outdoor barrels is the number one unregulated source of dioxin in Wisconsin.
A recent study found about 40 percent of northern Wisconsin residents burn their waste in barrels. DNR air quality specialist Kevin Kessler says it's estimated there are a half million burn barrels in the state.
Douglas County recycling coordinator Mary Klun says it's a problem across the state, but even more so in northern Wisconsin because people don't have quick access to recycling centers or curbside pickup.
The composition of household waste has changed over the years, which adds to the pollution. Today's trash contains more chemically-treated materials, synthetics, plastics and coated paper.
Kessler says it's legal to burn small amounts of leaves, clean wood and waste paper, but other materials should be taken to landfills. In fact, not doing so can result in a local fine of $25 to $1,000for the first offense.
