County braces for smog season

Tuesday, May 6, 2003 | 9:18 a.m.

Residents can reduce ozone pollution by:

Ozone, more commonly known as smog, is particularly a problem when the temperature gets up around 100 degrees or higher, and it won't be long before the Las Vegas Valley is into triple digits.

While Clark County is not among more than 50 urban areas in the United States that currently do not meet federal Environmental Protection Agency standards for ozone, local officials are acting to analyze the summertime pollutant.

"We see ozone as a pollutant of growing concern, but much of our attention in recent years has focused on helping the valley meet federal health standards for dust and carbon monoxide," said Christine Robinson, county air quality management director.

The Lung Association reported last week that Clark County logged 15 days from 1997 to 1999 when ozone levels in the valley were considered unhealthy for sensitive people, such as the elderly, children or those with respiratory problems.

From 1999 to 2001, the number of unhealthy air days dropped to seven.

In order to track sources of ozone, Clark County is launching a number of studies, assistant air quality director Carrie MacDougall said.

A study is under way to find out how much pollution comes from construction equipment engines, lawn and garden motors, diesel-powered generators, even smog drifting into the valley from Los Angeles.

Scientists are looking for volatile organic compounds, or VOCs, and nitrogen oxides, known as NOx, MacDougall said.

When VOCs and NOx are cooked by sunlight, ozone is produced.

"We're trying to find out the exact sources of these pollutants in the valley," MacDougall said.

A second study is analyzing weather conditions that lead to higher ozone levels, she said.

A third study is building an inventory of such varied sources as green plants and consumer products such as spray cans.

"Anytime you can smell something, that's a VOC," MacDougall said of aromatic sources such as air fresheners, cleaners and hair sprays.