Northern Utah's "bad air" season has begun, and along with it, restrictions on wood burning during high-pollution periods.
The Utah Division of Air Quality said Monday it is now enforcing the law prohibiting the use of most wood and coal stoves and fireplaces on "red" air-quality days.
The division's web page, http://www.airquality.utah.gov, posts "green," "yellow" and "red" forecasts each day for Wasatch Front counties prone to spikes of fine-particle pollution known as PM2.5.
Burning is allowed under "green" conditions. A "yellow" signal indicates pollution is building and people who use stoves or fireplaces are asked not to burn wood voluntarily.
But, when pollution nears unhealthy levels, the "red" signal alerts the public that it is mandatory to idle stoves and fireplaces.
In addition, people vulnerable to pollution including the very young, the very old and those with heart and lung problems are advised to reduce prolonged or heavy exertion outdoors when the red conditions are predicted.
PM2.5 pollution often builds up in the valleys when a layer of warm air traps cold air close to the valley floors, and there is no precipitation or wind to blow out the pollution. Sometimes these episodes can last for weeks.
"When the air quality is unhealthy," said Bo Call, manager of the Air Monitoring Center, "we need to drive smarter, and limit or prohibit firing up wood-burning stoves."
In addition to the online forecasts, the public can learn more about current conditions and wood-burning conditions by calling 801-536-0072 or 800-228-5434.