Air quality advisory issued for ozone levels

By Mary Manning

Friday, Aug. 28, 2009 | 10:06 a.m.

An air quality advisory for ground-level ozone from fires burning in Southern California has been issued for the Las Vegas Valley.

The Clark County Department of Air Quality and Environmental Management said that due to smoke heading into Southern Nevada from California, warmer than normal conditions in Las Vegas and existing pollutions levels, the advisory is in effect from Saturday afternoon through Monday.

Two new wildfires, the 2,000-acre Morris fire and the 500-acre Station fire, both in the Angeles National Forest, are spreading smoke that will reach the Las Vegas Valley by the weekend, air quality officials said.

Smoke is made of small dust particles, soot and other chemicals that can aggravate the lungs, especially those with chronic respiratory illnesses, but also healthy people.

Air quality officials said unhealthful levels of ozone are not expected today and are not occurring at this time.

Ozone is a gas that occurs naturally in the upper atmosphere, protecting earth from harmful ultraviolet rays from the sun.

When it occurs at ground level, ozone is a key ingredient of urban smog during the hottest days of the year in Clark County. Ground-level ozone builds up during afternoon hours due to strong sunlight, hot temperatures and automobiles spewing pollutants. Transportation exhaust and wildfire smoke also contribute to the mix.

When ozone levels are high, everyone should limit strenuous outdoor activity, especially people with respiratory diseases. Ozone can cause coughing, wheezing and shortness of breath even in healthy people.

To check the forecasts and measurements of ozone, go to the Department of Air Quality and Environmental Management Web site.