Thursday, March 11, 2004 | 11:04 a.m.
Spring is just around the corner, although the season's warm temperatures have already arrived. With those balmy conditions, however, often comes high winds.
And with the wind comes dust, recognized by the federal Environmental Protection Agency and Clark County as a serious air pollutant and potential health threat. The county's Air Quality Department is working to advise potential dust producers and those who could be affected by dust when the problem is imminent.
Carrie MacDougall, air quality assistant director, said her department will inform about 1,200 companies who have outdoor operations in the event high winds threaten. That program began in 2003 and MacDougall believes it has had a dramatic impact on the level of dust in the air on windy days.
Depending on the type of operation, the potential exposure of dust to the wind and how hard the wind is blowing, MacDougall's department can tell companies to shut down their operations or take preventive measures.
"We've seen a real dramatic difference," she said. MacDougall said that it is difficult to quantify the improvements in air quality, but several days last year when wind might have kicked up dust to a level violating the federal health-based standard for "particulate matter" in previous years did not in fact exceed the level.
"We feel very good that this has been an effective program," she said.
The other side of the program issues health advisories to local media, schools and doctors' office in advance of potential dust storms. Individuals can sign up for such warnings at Clark County's website at www.accessclarkcounty.com/ direct]connect.
Exposure to the fine dust can cause breathing problems in sensitive people or aggravate existing health problems, especially those affecting the lungs.
The rain Southern Nevada received in February and early this month has helped keep the dust down so far, but that effect could be temporary unless people follow the county's urging to stay off vacant land, air quality officials warn.
Off-road driving can make the region's dust problem worse by breaking the natural crust that forms on desert soils, they say.
"A lot of people think the desert is just a dusty place, but all the rain we've had has helped form a thick crust on top of our natural desert areas," Air Quality Director Christine Robinson said. "A natural desert crust can withstand winds of up to 35 miles per hour or more before dirt and debris break lose and become airborne.
"If somebody disturbs the desert, light winds can carry the dust miles," she said.
Clark County is required to meet federal health standards for fine dust by 2006 or face sanctions and stricter air-quality controls. Officials estimate that the amount of dust blowing off construction sites is now 65 percent of less than what would have been created since 2001 due to the existing regulations, stepped-up enforcement and cooperation from local construction companies.
"Our dust-control measures in place on construction sites are recognized as some of the toughest in the nation," Robinson said. "Our biggest challenge now is to educate residents about the importance of doing their part to keep the desert undisturbed in the urban Las Vegas Valley."
Robinson said drivers can do a lot by driving slowly or not at all on unpaved roads, avoiding shortcuts across vacant land, obey "no trespassing" signs and other vehicle-related moves.
"If drivers would keep their tires on paved roads and owners of vacant lots would take steps to stabilize their property, we estimate that we'd see a 70 percent reduction in airborne dust."
People can report excessive amounts of blowing dust at Clark County's dust hotline at 385-DUST (3878).
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