PORTLAND – A study conducted for Maine’s oil dealers concludes air quality could worsen if thousands of homeowners switch from oil heat to wood pellet stoves.

The study commissioned by the Maine Oil Dealers Association concludes pellet stoves generate more particle pollution and air toxins than oil furnaces.

It takes aim at a draft recommendation of the Governor’s Wood-to-Energy Task Force, which has set a goal of having 10 percent of homes heat with pellets.

“Advocating wood energy is fine, but you can’t tell untruths about oil,” said Jamie Py, executive director of the Maine Oil Dealers Association.

The Wood-to-Energy Task Force says that the switch to wood could help the state reduce its heavy dependence on costly oil heat and move toward cleaner-burning wood fuels.

Les Otten, the task force chairman, said heating oil dealers declined to participate in his group’s deliberations and now are using selective information to mislead people.

“They’re trying to protect their turf, protect their pocketbook, so people will continue to burn oil,” said Otten, who has launched a business, Maine Energy Systems, that’s promoting and selling high-efficiency, European pellet boilers.

The study was conducted by David Dixon of Dirigo Environmental Consultants. Dixon is a former air bureau manager at the Maine Department of Environmental Protection.

His report concluded that pellet stoves emit 10 times less particulate pollution than older wood stoves, but they still release 50 times more particles than oil furnaces.

He found similar patterns for carbon monoxide, and said pellet stoves also compared poorly in terms of air toxins, such as certain organic compounds.

“If we’re converting older wood stoves to pellet stoves, I’d go with that,” Dixon said. “But oil furnaces to pellet stoves, that’s a step backwards.”

Comparing the air-quality impact of oil and wood is complicated for a number of reasons, including the varied age and quality of equipment currently in use, experts say.

The Wood-to-Energy Task Force has been circulating a chart that compares pounds of particulate per heat output. The chart shows that both pellet boilers and oil furnaces have low emissions, while pellet stoves are somewhat higher. Newer wood stoves came next on the chart.

In Otten’s view, most people buying pellet stoves are upgrading from older ones or from wood stoves. So it’s wrong to compare them with oil furnaces, he said.

Regardless, though, he contends any EPA-certified wood heat is better for the environment than oil heat because it emits less carbon dioxide associated with climate change.

“The oil dealers want to talk about some pollution, but not other forms,” he said.