Pollution far exceeded healthy levels for a few hours from Lindon to Logan on the Independence Day evening.

"Once again, we did see the impacts from fireworks," said Bob Dalley, who oversees air monitoring for the state.

Preliminary data show one Ogden neighborhood's fireworks pumped so much smoke and heavy metals in the air Wednesday night, levels reached nearly 25 times the health standard for the fine-particle pollution called PM2.5 between 10 and 11 p.m.

PM10, the measure for larger-sized fine-soot pollution, was about six times the federal health standard for an hour.

Similar spikes also were recorded at Logan and in downtown Salt Lake City. And, following the Stadium of Fire July 4th celebration, the monitors 10 miles away in Lindon logged pollution levels seven times higher than the health standard for PM2.5 and more than double the standard for PM10.

All the numbers are preliminary - officials will check the real-time monitors against an actual count of particles on their official air filters - but none of them are very unusual for Utah's fireworks holidays, the Fourth and Pioneer Day on the 24th.

In past years, the spikes were high enough to cause violations of the federal health standards, and that may be true again this year, at least for the Ogden air station.

Brian Moench, a Salt Lake City doctor who co-founded Utah Physicians for a Healthy Environment earlier this year, found the pollution spikes shocking. He noted that heavy metals used to make the fireworks displays and the smoke they leave behind can be harmful to people, even if their exposure is only short-term.

He called the high pollution "acutely deadly" and noted that its harmful health effects can be seen within hours and can last for days.

"This is a kind of celebration in defiance of public health," he said, adding that high pollution "ought to be factored into how these events are handled."

He also said heart and lung patients and the parents of young children might want to be cautious about exposure to fireworks smoke.

fahys@sltrib.com

When particle pollution crosses the line

The U.S. Environmental Protection Agency has determined that 150 micrograms of fine particles 10 microns in diameter per cubic meter of air, averaged over 24 hours, presents a health risk.

It has deemed 35 micrograms of pollution per cubic meter of air, averaged over 24 hours, as the health standard for PM2.5, microscopic soot about one-fortieth the width of a human hair.

While Utah fireworks dumped heavy loads of fine particles into the air on Wednesday, the air was clean enough for most of the day that just the Ogden air-quality monitor recorded pollution levels that exceeded the 24-hour allowance.