The particulate pollution accompanying the spring storm was so thick in Magna, North Salt Lake and Salt Lake City that no one should have been outside, according to federal Environmental Protection Agency health advisory charts.
Two other cities, Ogden and Lindon, registered an unhealthy level of particulates in the air. So bad was the air that day and three others during the past four years, the state Division of Air Quality now must create a Natural Events Action Plan to protect public health when high winds batter Utah and send particulates known as PM10 above EPA standards.
DAQ environmental scientist David Strohm II, who is shepherding the natural events plan through the approval process, told the Utah Air Quality Board this past week that the state's natural PM10 reached unhealthy levels on April 15, 2002, April 1, 2003, April 2, 2003 and May 10 of this year.
In response, the Division of Air Quality this summer started a service that allows Utahns to sign up for e-mail alerts to warn them of wind storms by logging onto http://www.airquality. utah.gov.
The Natural Events Action Plan will for now cover only particulate pollution, but in the future could be expanded to include wildfire and volcanic and seismic activity, "basically, anything the Earth can throw at us," Strohm said.
The public comment period on the plan runs through Nov. 6.
The goal of the public education program is to explain the effects natural pollution has on community health, explain DAQ's efforts to minimize their effects and let residents know what they can do to protect themselves.
Particulate matter is made up of solids and liquids found in the air. Particles less than 10 micrometers in diameter - PM10 - tend to pose the greatest health concern. Fine particle pollution known as PM2.5 is only one-fortieth the width of a human hair, but has significant effects on human health. Heart disease, asthma and early death have been attributed to particulate pollution.
Wind-borne pollution is most prevalent in the spring, when the ground's thaw-and-freeze cycle loosens dirt that easily becomes airborne ahead of storm fronts. But it can accompany any bad weather, especially during the current drought.
The public can watch air monitoring in real time on the Web page http://www.air monitoring.utah.gov.
During the past 35 years, monitors have been moved around the state, then permanently located near communities of 10,000 or more.
Monitors are left in place at least three years, but if they don't show any air quality problems may be moved.
A monitor in Moab was shut down summer 2003 because there weren't any recorded violations of quality standards and the monitor was needed elsewhere, Bird said. But a monitor in St. George remains even though there haven't been any violations because community leaders want to stay ahead of any air quality problems as the region grows.
Sometimes citizen complaints will prompt DAQ to set up temporary survey stations, as they did this year in Milford to monitor a business that wasn't capturing leftover dust from grinding perlite, a glassy volcanic rock used in insulation, concrete, plaster and potting soil, Bird said.
Businesses whose operations contribute to particulate pollution, from the behemoth Kennecott Utah Copper mine to small plants in business parks to road graders, are required to suppress fugitive dust and monitor their activities.
While the Natural Events Action Plan won't for now encompass wildfire pollution, that isn't because fires never trip DAQ meters. In January, the agency cited the U.S. Forest Service for setting the Cascade Springs II fire a year ago, a prescribed fire that went out of control, burning 7,800 acres and pouring smoke across the Wasatch Front for a week.
But particulate from the fire never exceeded 24-hour standard, Bird said.
"As the air mass moved around that day, it hit different monitoring stations. If a monitor had followed the smoke around, it would have exceeded the standard."
