Noxious smoke from fireworks skyrocketed overnight Thursday.
Utah Division of Air Quality's monitors logged a midnight reading in Ogden at 725.6 micrograms of PM 2.5 pollution per cubic meter of air more than 20 times the health-based standard under the Clean Air Act following the Fourth of July celebrations.
At Salt Lake City's Hawthorne Elementary, the level was 75.9 at midnight, more than double the federal standard. And gauges at Lindon in Utah County, levels reached 222, or more than six times allowable levels. Pollution spikes also registered in Brigham City, Logan and Tooele.