SALT LAKE CITY (AP) — A group of Utah doctors is leading a campaign against expansion plans at three of five Utah oil refineries, saying the air in the Salt Lake basin is dirty enough and often fails to meet standards of the U.S. Environmental Protection Agency.

The upgrades at Utah's refinery row will allow Tesoro Corp., Chevron Corp. and HollyFrontier Corp. to more easily process the heavy or waxy crude oil coming out of eastern Utah wells.

The expansions appear to be motivated by a new pipeline that makes it easier for the Salt Lake area refineries to send more refined petroleum products to a larger market in Las Vegas.

One group fighting the expansions, the Davis County Community Coalition, said it would "not accept more toxic emissions in order to feed the fuel demands of out-of-state consumers."

"It is a question of how much industry we can grow in this non-attainment area with air quality such a concern," the coalition's president, Cecilee Price-Huish, told the Deseret News of Salt Lake City.

Another group, Utah Physicians for a Healthy Environment, has been sounding an alarm recently over weather inversions during Utah winters that can trap pollutants close to the ground. The group is suing Kennecott Utah Copper in a bid to block an expansion of the company's Brigham Mine on the west edge of the Salt Lake valley, saying mining dust puts more fine particulates in the air.

The doctor's group says refinery expansions will only add to the region's air pollution. Utah regulators are working under an EPA deadline of Dec. 15 to produce a set of plans that are expected to call for new controls on industrial emissions.

The refinery upgrades are under review by the Utah Division of Air Quality, which says that even with boosted production rates, refinery emissions will remain "well under" limits allowed by law.

Utah doctors, however, say there is no acceptable limit on chemical emissions that they say can damage the heart, lung, brain and eyes.

"There is a direct correlation between heightened levels of toxic pollutants, many of which are a big part of the refinery emissions mix ... and the increased incidence of health conditions such as asthma, heart disease, strokes and cancer," Dr. Brian Moench, president of the doctor's group, said in a statement.

His group held a town hall-style meeting Thursday for residents in Bountiful, which doctors say bears the brunt of refinery emissions. Bountiful is 8 miles north of Salt Lake City.

The refinery emissions that have doctors worried are benzene, a known carcinogen, sulfur dioxide, nitrogen oxide, carbon monoxide and volatile organic compounds. The refineries also release fine particulate matter, which doctors say can carry heavy metals into the blood stream.

The doctors' group says 16 percent of children in North Salt Lake and nearby Woods Cross have asthma, compared to 5 percent of the statewide population. Both cities are close to refineries and Interstate-15's concentrated tailpipe emissions, another major source of air pollution.

The oil companies say they are taking an opportunity to make their operations more efficient.

Chevron has said its $83 million upgrade will replace aging equipment but won't boost production. The company has a refinery at Salt Lake City's north end.

HollyFrontier plans to spend $225 million to boost production by 45 percent at the Woods Cross refinery, but it insists more modern equipment will lower overall emissions.

Tesoro says its Salt Lake City refining capacity will increase by 7 percent with $180 million in upgrades to handle the waxy crude oils from eastern Utah's Uintah basin. The company says new technology will reduce sulfur dioxide emissions by 1 percent.

A major reason for the expansions is the completion of a 399-mile pipeline that ships refined petroleum products to Las Vegas. The pipeline started operating earlier this year, and gives the Utah refineries a bigger market for their gasoline and other fuels.