BILLINGS - The Billings area recorded the worst air quality in the country Tuesday, according to an index compiled by the Environmental Protection Agency.
According to the EPA's Air Quality Index, Billings' air quality was considered "very unhealthy" early Tuesday afternoon, the only area nationwide to receive that designation.
The EPA develops the index by measuring levels of pollutants in the air daily, then translating them into a value to measure air quality.
The higher the number, the worse the air quality and Billings had a value of 210 as of 1 p.m., largely because of wildfire smoke moving down from Canada.
The good news is that the air quality in Billings improved over the day, with the EPA upgrading its index to "unhealthy" for Billings air at 3 p.m.
The EPA recommends people sensitive to bad outside air, including those with heart and lung problems, seniors and children and teens, to avoid strenuous outdoor activity or reschedule outdoor events outdoors.