Utah research says winter smog takes big hit from wood burning

by Judy Fahys- first published June 7,2013 in Salt Lake Tribune (see http://www.sltrib.com/sltrib/news/56427415-78/utah-pollution-winter-wood.html.csp)

Even though there might be just a few wood stoves and fireplaces pumping out smoke on northern Utah’s smoggy winter days, they are having a huge impact on air quality.

In fact, wood stoves and fireplaces, coupled with exhaust from cooking grills, make up the biggest contributor to the area’s winter pollution problem — roughly the same amount as all the emissions in the Salt Lake Valley from engines powered by gas and diesel.

That’s among the surprising findings of researchers at the University of Utah and environmental regulators who studied air-monitoring filters over four years.

Kerry Kelly, a U. chemical engineer and member of the Utah Air Quality Board, led the study that basically took apart the chemical recipe for winter smog to learn more about its ingredients and how much of each is in the soupy air.

Even with the burning restrictions in high-pollution periods of the winter, she noted from the research, stove and grill exhaust add roughly twice the proportion of emissions as previously projected.

“With wood burning,” she told the board on Wednesday, “there are a few number of sources that are having a big impact.”

The new information comes at an important time for state regulators. They have been struggling to find tools for cutting Utah’s winter pollution. And they must find the reductions soon to avoid a crackdown by the U.S. Environmental Protection Agency, which has put the state on notice about the unhealthy spikes of high PM 2.5 pollution northern Utah suffers during winter inversions.

Another interesting finding: The chemistry of the enormous Great Salt Lake might also be contributing to northern Utah’s pollution.

Kelly’s team found, on high-smog days, there was more chlorine in the air-monitor filters, and chlorine compounds are abundant in the lake.

One of them, magnesium chloride, is what US Magnesium captures from the lake salts and transforms into metal strengthener. Chlorine also used to be the pollutant that put the plant on the top of the nation’s toxic air-pollution list until a 2001 modernization that cut emissions by more than 90 percent

When it comes to wood/grill smoke, the study could fundamentally change the way we look at the pollution problem — and solutions.

Under the inventory regulators currently use to analyze pollution, smoky emissions account for about 16 percent of the problem and gas- and diesel-burning engines account for about 55 percent.

Based on the new research, smoky emissions are 38 percent — or roughly double previous estimates — and engine pollution is about 37 percent.