Three straight months of below-normal precipitation have contributed to higher ozone levels in Tooele Valley this summer, according to an air monitoring manager with the Utah Division of Air Quality.
“Air quality this summer is probably as bad as it has been since 2008,” said Bo Call of DAQ. “During the last five or six summers, we’ve had thunder boomers clear out the air, and we had cloud cover to block the sun. That was not the case this summer.”
He said most of Tooele Valley’s pollution comes from Salt Lake Valley because of a condition similar to lake-effect storms during winter.
“Just like you get snow from lake-effect in the winter, you get pollution blown in from over the lake in the summer,” Call said.
“Pollution is generated in Salt Lake Valley and bounces around, and on some days blows out over the lake,” he added. “The pollution cooks out there for a while and then goes wherever the breeze takes it. If the wind is blowing to the south, it takes it into Tooele.”
Call said ozone pollution is created in the atmosphere when chemicals react to sunlight. According to the U.S. Environmental Protection Agency, high ozone levels can cause the muscles in the lung’s airways to constrict, trapping air in the alveoli. This leads to wheezing and shortness of breath.
Call said ozone levels for Tooele Valley in July, measured at a monitoring site in Erda, exceeded the standard of 70 parts per billion 13 times. A monitor in Salt Lake City and another in Bountiful each showed measurements over the standard 14 times during the month.
Call said mountains block Salt Lake Valley’s pollution from blowing into Summit and Wasatch counties, but that’s not the case for Tooele Valley.
“The Oquirrhs jut out there, but they do not prevent the air from going around them out to the lake,” he said.
Call said pollution is measured by particulates in the winter and ozone in the summer. He added that winds from the north have pushed pollution from recent fires in Idaho and Canada into northern Utah.
He said air standards are based on 24-hour averages.
“During a windstorm or on the Fourth of July, we may actually see air quality reach a hazardous level for a few hours, but the air would need to stay at that level for 24 hours before we would call conditions hazardous,” Call said.
He estimated that 55 percent of pollution is caused by vehicles, and about 30 percent from area sources like houses and hospitals. Industry creates about 15 percent of the pollution, he said.
Tooele’s air conditions can be found daily at tooelehealth.org. According to the website, conditions range from good, moderate, unhealthy, very unhealthy and hazardous.
Good air quality poses little or no risk. With moderate air conditions, some people should consider reducing prolonged or heavy outdoor exertion.
Unhealthy means people sensitive to bad air should reduce prolonged or heavy outdoor exertion. This includes people with lung disease, such as asthma, children or older adults and people who are active outdoors.
Tooele physician Ronald Trudel, MD, said weather and low barometric pressure affects a lot of his patients with emphysema and chronic obstructive pulmonary disease (COPD).
“Any weather inversion with high particulate matter affects both asthmatics and those with emphysema,” he said.