SALT LAKE CITY — A stormy, wet summer has helped keep harmful ozone at safe levels in the Salt Lake City area, state environmental officials said Wednesday.
Ozone levels have surpassed the safe threshold established by the Environmental Protection Agency six times this summer — compared with 22 times last summer, said Bo Call, air monitoring section manager with the Utah Division of Air Quality.
Ozone often creeps up to dangerous levels during the midafternoon heat, but this summer it was tamped down by frequent afternoon storms and showers, Call said.
Ozone is an invisible gas produced by smog that can tax the lungs of even healthy people. It is worst in the summer when sunshine and hot weather cook ozone from tailpipe and other emissions. Doctors say ozone often goes overlooked, but it acts on lung tissue like sandpaper.
There has been twice as much precipitation this summer in Salt Lake City compared with last year, said National Weather Service meteorologist Christine Kruse.
It has been much cooler too. The average temperature this summer in Salt Lake City has been five degrees lower than last summer, the warmest on record since 1874, Kruse said.
The lower levels of ozone were first reported by the Deseret News.
In Utah, most of the focus on air quality is directed at the smoggy winter air that becomes trapped by towering mountains that flank the Wasatch Front, where more than two-thirds of the state's residents live.
The summer ozone problem doesn't usually receive as much attention, though doctors last year made efforts to warn people about the harmful effects of ozone.
The safe ozone threshold set by the Environmental Protection Agency is 75 parts per billion. The high so far this year in Utah has been 77, Call said. Last year, the levels reached the 80s on several occasions.
The storms and wind that usually accompany rain flush out the pollutants that make up ozone, Call said. Stagnant air and rising heat, in contrast, fuels dangerous ozone levels.
"Your pollutants are staying right there," Call said.