Just four years ago, Maine took an important step forward in reducing dioxin in the environment by setting tough standards for paper mill discharges in rivers. Legislators are expected Monday to hear a bill that would reduce this toxin in the air. It is a reasonable bill that could make a major difference in air quality and deserves support.

LD1543 stops the burning of trash that contains the plastic polyvinyl chloride (PVC) because it releases chlorine, which under the right circumstances produces dioxin in the air. The dioxin then settles back to the ground, to be consumed by animals or carried by rain or snow into rivers and entering the food supply. Dioxin, which the Environmental Protection Agency and the International Agency for Research on Cancer consider to be a human carcinogen, is also considered a contributor to birth defects, heart disease and diabetes.

PVC is found in building materials such as waste pipes, house siding and flooring and in home furnishings, some plastic bottles and packaging. (For the curious, many plastic items include a small little triangle with a number inside. PVC is number 3. Nos. 2 and 5 plastics are much cleaner.) The state’s Department of Environmental Protection figures that the burning of these products contributes to about 50 percent of Maine’s airborne dioxin, with about half of that coming from burn barrels and 13 percent from solid-waste incinerators and 11 percent from medical-waste incinerators.

Maine’s paper-mill rules in 1997 were considered some of the toughest around when passed. The new dioxin proposal would simply keep the state current with what other places are considering or, with the recent announcement by Maine hospitals that they would be reducing their use of PVC and getting it out of the medical-waste stream, current with what is going on elsewhere in Maine. LD 1543 calls for putting waste PVC in landfills rather than sending it to trash incinerators, plans an education campaign to help consumers understand the difference between PVC and other types of plastic and encourages the state to look for alternatives to PVC products.

The bill has bipartisan support, including Bangor sponsors Sen. Tom Sawyer and Rep. Tina Baker. With Maine’s hospitals already committed to making progress in this area, the next step is for municipal-waste incinerators to stop accepting this type of plastic and turning it into a toxin in the air.