JEFFERSON CITY, Mo. — Smoke wafting from wood fires has long provided a familiar winter smell in many parts of the country – and, in some cases, a foggy haze that has filled people’s lungs with fine particles that can cause coughing and wheezing.

Citing health concerns, the Environmental Protection Agency now is pressing ahead with regulations to significantly limit the pollution from newly manufactured residential wood heaters. But some of the states with the most wood smoke are refusing to go along, claiming that the EPA’s new rules could leave low-income residents in the cold.

Missouri and Michigan already have barred their environmental agencies from enforcing the EPA standards. Similar measures recently passed Virginia’s legislature and are pending in at least three other states, even though residents in some places say the rules don’t do enough to clear the air.

A year ago, Patricia Aho, commissioner of the Maine Department of Environmental Protection, and Gov. Paul LePage criticized what were then proposed rules by the EPA.

On Sunday night, DEP spokesman Karl E. Wilkins said in an email that enforcement of the new regulations is not the state’s responsibility. He said the federal government will be responsible for making sure that manufacturers and retailers of wood heaters are in compliance.

“I can’t speak to the situation in other states,” Wilkins said, referring to Missouri and Michigan. Instead, the state has been reaching out to Maine retailers and manufacturers to help inform them of the new EPA standards.

The EPA on Feb. 3 promulgated the new regulations governing wood-burning appliances. Under the rules, retailers may not sell any wood stoves or pellet stoves after Dec. 31 that do not meet regulatory requirements.

Wilkins noted that Aho testified at an EPA hearing in Boston in February 2014 about the concerns she had with the regulations the agency was proposing then. Aho followed up her testimony with a 22-page letter in May to EPA Administrator Gina McCarthy.

Aho told McCarthy that from 2005 to 2012 the Northeast had seen the highest increase in the use of wood as the main source for heating a home. She said lower-income households consume more wood. They also appear to be using older, inefficient wood stoves, Aho said in the letter, which Wilkins provided Sunday night.

“In a state that is predominantly rural, has the lowest per capita income in New England, has some of the oldest housing stock nationally, and is demographically the oldest in the nation, Maine citizens should have access to affordable, efficient primary heating sources,” Aho wrote.

She encouraged the EPA to spearhead an energy-saving incentive program that would encourage Maine residents to replace older, less efficient wood stoves with new, more efficient devices that consume less wood and provide more energy.

Aho told the EPA at its hearing in Boston last year that Maine supports regulations which result in more efficient and environmentally beneficial wood-burning devices and agrees that more should be done to reduce the amount of wood smoke in the air. But she also said the rules may have unintended negative consequences.

“The department maintains that EPA’s proposal would deter homeowners with older, non-certified stoves, which are a high source of emissions, from purchasing new units due to the space limitations, ease of use and associated costs to purchase, maintain and operate,” Aho said in a statement after the hearing in Boston.

LePage also weighed in last year on the proposed EPA regulations, which took effect last month.

“As the governor of a state where people in our rural counties depend on wood as a heating source, I know just how much the EPA’s draft rule for residential wood heaters jeopardizes Maine’s future economic and environmental success and burdens the state’s most vulnerable,” LePage said in a statement issued after the hearing.

“The draft rule would not fulfill its purpose to reduce the amount of harmful wood smoke in the air and in fact would do just the opposite, making it prohibitively expensive for homeowners to purchase a new, more efficient stove,” LePage said.

Heating with wood is a cherished and thrifty tradition in Maine. A greater percentage of homes use wood as their primary heat source – 14 percent – than any state other than Vermont, according to U.S. Census figures. An estimated 50 percent of Maine homes also use wood as a supplemental heat source.

Gary Spalding, who works at Embers Stove & Fireplace Shop in South Portland, spent 35 years in the industry. He said wood stove emissions can be dramatically reduced with newer stoves.

Spalding predicts that woodstoves will remain popular in northern New England because of “the warm glow in the living room.” The stoves are popular because of aesthetics as much as functionality, he said.

“The cat and dog like it too,” he said.

NEW RULES STOKE FEARS

Elsewhere in the U.S., the EPA’s new rules are stoking fears that some residents won’t be able to afford new stoves when their older models give out.

“People have been burning wood since the beginning of recorded time,” said Phillip Todd, 59, who uses a wood-fired furnace to heat his home in Holts Summit, Missouri. “They’re trying to regulate it out of existence, I believe, and they really have no concern about the economic consequences or the hardship it’s going to cause.”

Others contend the real hardship has fallen on neighbors forced to breathe the smoke from winter wood fires.

The EPA typically relies on states to carry out its air quality standards. But states may not be able to effectively thwart the wood-burning rules, because federal regulators could step in to do the job if local officials don’t.

“If the EPA wants to come in here and enforce it, come on in. (But) I’m not going to help them,” said Michigan state Sen. Tom Casperson, whose law barring state enforcement of the EPA regulations takes effect March 31.

About 10 percent of U.S. households burn wood, and the number relying on it as their primary heating source rose by nearly a third from 2005 to 2012, the latest year for which federal figures were available.

The EPA’s new rules, which are to be phased in over five years, apply only to new wood heaters and won’t force anyone to get rid of their older models.

The EPA estimates the restrictions will reduce fine particle emissions from wood heaters by nearly 70 percent. It says that will result in an average of one fewer premature death per day and yield about $100 of public health benefits for every $1 of additional cost to manufacturers.

The rules mark the first update since 1988 for indoor wood stoves, which include both free-standing models and ones that fit inside traditional fireplaces. The EPA also is imposing its first-ever emission mandates on wood-fired furnaces and outdoor boilers, which use fire to heat water that is circulated through pipes to warm homes.

Nine states and dozens of communities already had required cleaner emissions for outdoor wood-fired boilers before the EPA acted, according to the Hearth, Patio & Barbecue Association.

The states objecting to the EPA’s standards include some of the biggest wood burners. Michigan ranked tops nationally in fine particle emissions from residential wood burning in 2011, the latest year covered by EPA statistics. Missouri and Virginia both ranked in the top 15. Bills to bar enforcement of the EPA regulations also are pending in Wisconsin and Minnesota, which ranked second and third, as well as in West Virginia.

The heavily forested states of Vermont, New Hampshire and Maine are among the top five in the country for the per capita emission of pollutants from wood stoves used to heat homes.

Disputes over wood heaters have sparked legal battles among neighbors. In late January, for example, an Indiana judge rejected a request from Mable and Gary Bowling for a preliminary injunction forcing one of their Rush County neighbors to stop using an outdoor furnace. The Bowlings claimed the smoke was unhealthy; the neighbors claimed the Bowlings had harassed them by repeatedly contacting police or firefighters.

Mable Bowling contends the wood smoke has worsened her asthma and led to other respiratory problems. “What we’re breathing is slowly killing us,” she said.

Staff Writers Dennis Hoey and Tux Turkel contributed to this report.