Clark County issues ozone advisory for spring, summer

In the Las Vegas Valley, warm weather means swimming, grilling and ozone pollution.

Clark County’s Department of Air Quality issued an advisory for ozone this week that will be in place throughout the spring and summer.

Many associate ozone with the layer of atmosphere protecting the Earth from harmful ultraviolet rays, but ground-level ozone is a key component of urban smog, which can cause irritation for people with respiratory conditions.

But what is ozone?

Ozone is a form of oxygen with three molecules instead of two. Emissions from automobiles and factories mix with heat and sunlight to form ozone. Regional wildfires, which are common in the warm seasons, also contribute to air pollution.

Much of the ozone pollution in Las Vegas usually is not produced locally, explained county air quality monitoring manager Phillip Wiker. It comes in from Los Angeles and stagnates in the valley.

Jean, a small community about 30 miles south of the valley, has been wallowing in high levels of ozone even though it creates very little pollution. Wiker said the ozone blew in from fires in Mexico.

“For a metropolitan area this size, we have exceptional air quality” because there is not much industrial emission, he said.

Chris Stachelski, a meteorologist with the National Weather Service’s Las Vegas office, said it is all about the wind. Very light winds trap particulates in the valley near the ground, like a lid on a pot.

While Las Vegas does not have pollution as bad as many other cities, ozone is highly corrosive when inhaled and can reduce lung function and worsen respiratory illnesses such as asthma or bronchitis. Large doses even can induce coughing, wheezing and shortness of breath in healthy people. When ozone levels are high, people might want to limit outdoor activities.

The county monitors ozone levels at stations across the valley and maintains a website to inform the public of current conditions at http://airquality.clark­countynv.gov.

To save people the headache of having to figure out measurements in parts-per-million, a color code is used in which green means “good,” orange means “unhealthy for sensitive groups” and maroon means “hazardous.”

And ozone degrades pretty quickly, usually clearing out after sunset. This is why the county recommends filling up your gas tank after dark.

The importance of regular vehicle maintenance and driving as efficiently and as little as possible also is emphasized. Conserving electricity and gasoline will reduce air pollution further.

Contact reporter Wesley Juhl at wjuhl@reviewjournal.com and 702-383-0381. Find him on Twitter: @WesJuhl.