WASHINGTON — Source reduction and recycling of plastics and other materials in the municipal garbage stream are the best ways to reduce greenhouse gas emissions, according to a preliminary Environmental Protection Agency report.
The conclusions of EPA's first study on the topic are not surprising and reinforce the agency's overall position that source reduction and recycling are environmentally preferable to landfilling and other options, said Clare Lindsay, special assistant to the director of the municipal and industrial solid waste division.
The results could provide ammunition for recycling programs that are ``under seige'' by quantifying an environmental benefit beyond simply helping landfills last longer, she said. The recycling community long has debated whether the environmental costs of transporting materials outweigh benefits, but the study demonstrates that is not a big concern, she said.
``It gives people another reason to, if they are inclined to source reduce and recycle,'' she said.
The report, ``Greenhouse Gas Emissions from Municipal Waste Management,'' tracked the amount of carbon — a key building block of greenhouse gases —emitted by various disposal and reuse options for high and low density polyethylene, PET, aluminum cans, steel cans and several types of paper.
Source reduction, naturally, did not add to carbon emissions, while the report said recycling of the three plastics emitted 750-794 pounds of carbon per 2,000 pounds of material used.
Landfilling and incineration fared much worse, with landfilling yielding two to 21/2 times as much carbon as recycling, and incineration producing about four times as much as recycling for the three plastics.
The results for plastics were mixed compared with aluminum cans, with aluminum faring much better in recycling and much worse in incineration and landfilling.
Recycling aluminum reduces carbon emissions, while landfilling and burning give off two to three times as much carbon as the same process for plastic.
All types of paper, however, generally produced less carbon than plastics, the study found. It looked at newspaper, office paper and corrugated cardboard.
Source reduction and recycling of municipal waste account for about 5 percent of the overall U.S. government targets for reducing greenhouse gases. The United States signed an international agreement in 1992 to reduce greenhouse gas levels in 2000 to their 1990 levels.