Parts of Utah currently have some of the worst air quality in the country, and a health alert remains in effect for the week.

A current map from the U.S. Environmental Protection Agency shows red, or “unhealthy” air over Salt Lake City up through Brigham City.

According to the website, that means people in the area may begin to experience some health effects, especially those with lung sensitivities.

Yellow on the map indicates moderate air quality, meaning air quality is acceptable. Orange means unhealthy air for sensitive groups.

Authorities say there is no relief in sight after pollution levels spiked earlier this week.

Weber County started off the New Year with nearly three times the federal standard of pollution, with 73 micrograms of fine soot per cubic meter.

According to the EPA, Salt Lake City, Phoenix, Las Vegas and central California are suffering from the worst air in the country.

Utah regulators say most of the pollution comes from tailpipe emissions, so residents are encouraged to drive less this week if possible.

Also, those with heart or respiratory problems are encouraged to stay indoors and reduce physical activity.

The next chance for an improvement in air quality may come on Saturday, according to KSL Meteorologist Dan Guthrie.

via Utah’s air quality Thursday among worst in nation, EPA map shows | ksl.com.