More stringent air-pollution rules issued by the Environmental Protection Agency this week mean Utah will have difficulty complying and may risk losing federal transportation money.

The new EPA regulations lower the air-quality limit for small particulate matter from 65 micrograms per cubic meter in a 24-hour period to 35 micrograms per cubic meter.

In 2010, Utah officials will be required to tell the EPA whether the state meets the new standard. By April 2011, if the state is not in compliance, no federal highway construction money could be contributed to projects here. Also, the state would not be able to fund projects that would have a regionally significant impact on roads.

Funds to help combat air and water pollution highlight Gov. Jon Huntsman Jr.'s budget request for the Utah Department of Environmental Quality.

The governor wants the funding to help the state control particulate air pollution, after the new federal rules designed to control exposure to these fine particles went into effect this past Monday. He also wants funds for studying mercury levels in the Great Salt Lake, freshwater areas and in fish, and to determine the source of the pollutant.

The air pollution from small particulate matter is dangerous because the particles can lodge in the lungs, causing health problems. As part of a regular five-year review of air-quality standards, a science panel for the EPA examined the health limit of 65 micrograms per cubic meter, said Dianne R. Nielson, director of the Utah Department of Environmental Quality.

"Their review determined that there were really health impacts" at that concentration, she said, and with the rule change, "basically it's reduced almost in half."

Utah has met all previous air-pollution standards. But meeting the new regulation "is going to be real problematic," Nielson said.

Areas having the most difficulty meeting the rule are those along the Wasatch Front and in Cache County. The problem is evident during winter air inversions.

"Those very, very fine ... particles come principally from vehicles," she said. They can be produced by any engine or combustion of hydrocarbons such as oil, gas and coal.

In some places, such as Cache County, the material is based on ammonia. State experts are trying to determine how much of the air pollution in that county is caused by vehicles and how much comes from the dairy industry.

Controlling the pollution is the goal of strategies the DEQ is developing. Also, some benefit should come from new vehicle standards for engines and fuel, which will help reduce engine emissions, because newer vehicles create less pollution, Nielson said.

Will officials need to place mandatory restrictions on vehicle use at certain times? "I think it's too early to say," Nielson said.