On Dec. 4, Utahns saw a thick layer of smog covering the Salt Lake Valley, making travel especially difficult for those commuting to work or school.
FOX 13 reported that Salt Lake City had the highest air quality index in the country with an AQI above 150, almost nine times higher than that of Los Angeles.
The dirty, inverted air and ensuing fog conditions also caused flight delays and cancellations due to low visibility on runways. As the fog rolled in, Salt Lake International Airport was forced to divert incoming Salt Lake City arrivals to neighboring airports.
Due to low visibility about two dozen flights were diverted from SLC to nearby airports late this morning. Passengers are encouraged to check with their airline for possible flight delays.
— SaltLakeCityAirport (@slcairport) December 4, 2019
How pollution affects people
Air pollution poses little to no risk when the AQI is in a range of 0-50. However an AQI over 150 is considered a health risk to anyone who goes outside, particularly those with a history of lung and heart diseases.
The same day Salt Lake County’s AQI exceeded 150, Utah County reported an AQI between 101-150, which is considered “unhealthy for sensitive groups” — those who suffer from asthma, children and elderly individuals.
How “The Greatest Snow on Earth” hurts and helps AQI
According to Utah Department of Health, particulate matter is made up of dust particles, soot and vehicle emissions. The winter inversions in Utah cause higher levels of particulate matter because of the lack of breeze and constant high temperatures.
By using measurement sizes of 2.5 for fine particles and 10 for inhalable coarse particles, officials can determine the dangerous effects of these complex particles and droplets on respiratory systems.
Strong winter storms typically clear up most standing inversions, pushing Utah’s AQI back into the healthy range of 0-50. Conversely, the cold temperatures following a storm, combined with snow on the ground, create prime conditions that allow another inversion to set in.
What to do during bad air days
When the AQI reaches an unhealthy level, Utah’s Department of Environmental Quality recommends minimizing activities with heavy exertion and moving all outdoor activities indoors. The DEQ also encourages carpooling, using public transport, wearing face masks, and abiding to Utah’s “No Burn Days” to help limit pollution in the state.
The Utah Division of Air Quality issues mandatory “No Burn Days” from Nov. 1 to March 1. “No Burn Days” prohibit residences in Box Elder, Cache, Davis, Salt Lake, Tooele, Utah, and Weber counties from using wood fireplaces, wood stoves, pellet stoves, and coal-burning stoves.