Ravell Call, Deseret News
An inversion covers downtown Salt Lake City.

SALT LAKE CITY — Doctors and other medical professionals worried about the health risks of Utah's bad air took their concerns directly to the governor's office Wednesday, delivering a letter that encourages Gov. Gary Herbert to declare a health emergency.

"The largest cities in Utah are, once again, experiencing the worst air pollution in the country. This has become an all too common part of the winter season and it is a genuine public health emergency," states the letter, signed by more than 100 health care professionals, including 75 doctors.

"Although there is no safe level of air pollution, what we are exposed to now is comparable to forcing all members of the community to become active smokers, and that includes children, infants, and pregnant mothers," the letter states.

The physicians want industrial polluters including oil refineries and Kennecott Utah Copper to decrease production by 50 percent. They also want to drop freeway speed limits to 55, encourage mass transit, prohibit wood burning and launch a public service campaign.

The governor's spokeswoman said the governor can't control everything and agreed with a shared responsibility approach.

"The reality we face is that 50 percent of the pollution we have in the air right now is caused by tailpipes. We simply have to cut back," Herbert's spokeswoman Ally Isom said.

Much of the doctors' urgency comes from the severity of the inversion days this year. So far this season, there have been 22 alert days, and there are still five weeks to go in the troubling winter inversion season.

"We call on the governor, the Legislature and the mayors of the cities of the Wasatch Front to take emergency action to address it, and do everything possible to immediately reduce sources of air pollution," the letter states.