SALT LAKE CITY (AP) -- Environmental advocates will try to persuade the Utah Supreme Court Wednesday that the state's approval of an oil refinery expansion would add to air quality woes in northern Utah, parts of which suffer from some of the nation's worst air in winter.
The legal battle marks the latest illustration of the intense scrutiny air quality issues receive in the greater Salt Lake region.
The air problems in Utah's urban corridor during the winter result from weather and geography with cold, stagnant air often settling in the bowl-shaped mountain basins, trapping tailpipe and other emissions that have no way of escaping.
Doctors warn that breathing the polluted air can cause lung problems and other health concerns. State officials ban wood burning on many days, and they constantly plead with residents to carpool and take other measures to cut down on pollution.
At issue in this case is the expanded scope of work at the Tesoro oil refinery just north of Salt Lake City.
State officials gave approval in 2012 for Tesoro to increase operations at the facility, but a coalition of environmental groups sued.
State regulators stand behind the decision, arguing in court documents that Tesoro met all state and federal requirements. But the coalition — which includes Western Resource Advocates, Utah Physicians for a Healthy Environment and the Sierra Club in Utah — argue that the state should require stricter emissions controls.
The particles emitted from refineries and other pollution penetrate people's bodies, making it difficult to for the lungs to work and causing a host of health problems, said Joro Walker, senior attorney for Western Resource Advocates in Utah.
"We have all felt our eyes and lungs burn, fretted over whether to let our children outside to play, worried about parents and grandparents with heart problems - even taken them to the emergency room as their symptoms worsened - and watched our neighbors with asthma struggle to breathe," Walker wrote in a court filing.
Doctors say people — especially pregnant women and children — should stay indoors, or at least avoid active outdoor exercise under the sickening yellowish haze. Elderly people with heart disease are most at risk, they said.
Doctors say breathing the air is like smoking, because you are sucking in particles that make it difficult for lungs to function.
Utah state legislators and officials are aware of the problem, and they are actively working to address it. The state passed 22 new rules last year to reduce polluting emissions. They include new a ban on the sale of aerosol deodorants and hair spray that contain hydrocarbon propellants and a requirement that restaurants add a catalytic oxidizer to charbroilers.
From 2012-2014, Salt Lake City averaged 43 micrograms of soot per cubic meter, known as PM 2.5, exceeding the federal clean-air limit of 35, said Bo Call, manager of the Air Quality division of the Utah Department of Environmental Quality.
Call said 2013 was a particularly bad year because of weather conditions that trigger inversions: snow on the ground, frigid temperatures and high pressure that traps the murky area in the valley. "That's the perfect storm for pollution developing," Call said.
Because of those unsafe pollutions levels, Utah is in line to get downgraded next year to a more serious air quality designation by the Environmental Protection Agency, which would mean the state will need to come up with another set of even stricter regulations, Walker said.
"That acknowledges how dire the situation is," Walker said.