Wind brings dust, but it blows pollution out of valley

Dan Kulin and Ed Koch

Tuesday, June 24, 2003 | 11:14 a.m.

It may have been a dirty, dusty day in the Las Vegas Valley Monday, but officials said it wasn't unhealthy, according to pollution monitoring stations.

Ozone and fine dirt and dust particles were at moderate levels at several monitoring stations around Clark County Monday, according to information on the Clark County Department of Air Quality Management's website.

"Moderate" is one level below "good," the best ranking for air quality. "Unhealthy for sensitive groups," such as people with asthma and other respiratory conditions, is the level below moderate. The levels below that are "unhealthy," "very unhealthy" and "hazardous."

The reason it looked so bad but wasn't was the wind, which not only stirred up some dust but it was also blew pollution out of the valley.

"Anytime you get wind around 15 mph, you have less chance of having an ozone problem," said Femi Durosinmi, air quality monitoring supervisor at Air Quality Management. "If the air was stagnant, we definitely would have had an unhealthy day for ozone."

Barry Pierce, a meteorologist with the national Weather Service in Las Vegas, said winds are forecast to reach 25 mph this morning, and die down to 10 to 15 mph this afternoon. On Monday, winds were generally 15-25 mph, he said.

The winds will continue to die down and the temperature will rise throughout the rest of week, reaching 100 degrees by Thursday or Friday, Pierce said. Today's high temperature high was expected to be around 92 degrees, which was Monday's high.

There were two unhealthy ozone days in May and two in June, Durosinmi said, noting that there have been no unhealthy days in the valley for dust.

The high pressure area over much of the West has contributed to the appearance that there is a lot of pollution in the valley, something that is not uncommon during the summer months, Durosinmi said.

He said ozone is a major summer concern because it can make people sick with irritable cold symptoms. Particulate matter, or dust, can also cause respiratory problems.

Moderate levels of ozone were found Monday at 14 of the 15 monitoring stations that measure ozone. The only good reading was at the City Center Station off Las Vegas Boulevard and U.S. 95.

The highest levels of ozone were measured in Mesquite and Apex, the northeast most stations in the valley, and at the Joe Neal School in the northern most station in the valley.

Nine of the 16 stations that measure "PM10" -- fine particles of dust measured as particulate matter of 10 microns and less -- had moderate readings. The highest readings were at the East Craig Road and Apex stations, both in Northeast Las Vegas.

Air Quality Management tracks levels of ozone, carbon monoxide, and particulate matter at 22 stations around the county.

The air quality ratings are posted at www.ccairquality.org.