"It's gotten out of control," said Stewart, who lives on Salt Lake City's west side.
"I would like to see a reduction in fireworks," she said. "It's costing our health, our safety, our quality of life."
Federal regulations don't treat these celebratory pollution spikes the same way they do pollution during, say, northern Utah's winter inversions. Instead, they have what amounts to a "fireworks loophole," an official category for pollution tied to fireworks on Independence Day, Chinese New Year, and other religious, community and patriotic events. They are dubbed "exceptional events."
In its most recent riff on the subject, a 2007 regulatory update, the EPA explained that although fireworks-related pollution is not specifically mentioned in the Clean Air Act, the agency "believes that Congress did not intend to require EPA to consider air-quality violations associated with such cultural traditions in regulatory determinations."
Meanwhile, the rationale for such a loophole goes back to the very beginning of American history. Widely cited reports tell how John Adams wrote about the importance of celebrations like these in a July 3, 1776, letter to his wife after the Continental Congress.
"The day will be most memorable in the history of America. I am apt to believe that it will be celebrated by succeeding generations as the great anniversary festival. It ought to be solemnized with pomp and parade, bonfires and illuminations [fireworks] from one end of this continent to the other, from this time forward forever more."
Still, it's little consolation for people who suffer from the sooty smoke that often clouds the air after fireworks have been set off.
In Ogden, July 4th celebrations this year put so much soot into the air that monitors showed PM 2.5 particulate more than 20 times above levels considered acceptable for health. In Utah County, the pollution was more than six times the acceptable concentrations, and in Salt Lake County, they were more than twice as high as would normally be considered acceptable.
In general, those levels are much higher than the winter smog that plagues northern Utah for days at a time.
Bo Call, who oversees the state's air-pollution monitoring efforts, said much depends on where you are and what day of the week the fireworks holidays fall in any given year.
"Some cities go all out for it more than others," he said. "We generally see [pollution] increases beginning three days in advance."
The Fourth of July spikes have become so common that Division of Air Quality staff have become accustomed to filing reports each year that prove the pollution on the air filters came from fireworks. Otherwise, state regulators would have to find emission reductions year round from homes, transportation and industry to make up for the fireworks pollution.
Joel Karmazyn, who writes those exceptional-event reports, noted that while fireworks pollution does increase around Pioneer Day, it does not reach the same sort of unhealthy levels as on the Fourth of July.
"It's just a smaller amount of fireworks," he said.
The state departments of Health and Environmental Quality also issued a warning in early July.
"Exposure to particulate matter may cause eye, nose and throat irritation leading to coughing and sinus irritation," the agencies said in a news release, noting that the very young, the very old and people with heart and lung trouble are most affected. "Headaches, burning eyes or runny nose are also common."
Rep. Jim Dunnigan, R-Taylorsville, said lawmakers have helped the air quality by scaling back the number of days that fireworks are allowed. Under a bill he sponsored in 2011, fireworks were permitted for about a month.
Because of citizen complaints, in 2012 the Legislature cut back that window to the week surrounding the Fourth and the week surrounding the 24th.
"We've cut the discharge in half," he said.
Stewart says she's opposed to fireworks from the Salt Lake Valley baseball and soccer stadiums.
"I think it should be a violation of the Clean Air Act," she said. "We're adding pollution to our air shed, and we can't afford to do that."