We're talking about unhealthy air on the Wasatch Front, compounded by a temperature inversion. When the air is colder on the valley floor than it is several thousand feet higher, air pollutants are trapped in Utah's valleys. The result is the soup we all breathed Monday and over the weekend.
Usually the inversions begin in December. But lately about the only thing predictable about Utah weather is that it's unpredictable. Normal isn't normal anymore.
What is completely predictable is that if Utahns don't change their polluting ways, this situation will continue to get worse. The reason is explosive population growth and an even steeper spike in the miles Utahns drive in their cars, trucks and SUVs.
Automobiles and diesel engines are major contributors to the pollutants that foul Utah's air, particularly soot called PM2.5. They are called that because the particles are less than 2.5 micrometers in diameter. By comparison, 10 micrometers is about one-seventh the width of a human hair.
These tiny soot particles are dangerous because they lodge in the lungs and are not expelled. They cause nose and throat irritation, lung damage, bronchitis and early death.
Monday was an "Air Action Day," meaning that the Utah Department of Environmental Quality warns that pollution levels are building up and asks Utahns to reduce driving by combining trips, carpooling or using mass transit. It also asks people not to use wood-burning stoves and fireplaces.
If you want to know what else you can do to reduce air pollution, the DEQ has a boatload of suggestions - 50, to be exact - at its Web site, www.cleanair.utah.gov.
A headline in Monday's Tribune said, "Inversion to blame for Utah's mucky air." That's wrong. Too many Utahns driving too many cars, together with other activities of our industrial society, are to blame, not the temperature inversion. Obviously, we aren't going to give up our cars. But we can work harder to reduce trips and use mass transit.
We've got to do it every day, not just on "Air Action Days." Because if we don't make a habit of cutting down our polluting ways, we won't do it during an inversion. And if we don't, eventually we'll all suffer from lung diseases.
