Smoke drifting into the Las Vegas Valley from a wildfire in the San Bernardino, Calif., area has prompted Clark County to issue an air quality advisory.
The advisory for smoke and ground-level ozone is in effect through Friday.
At this time, unhealthy levels of air pollution are not occurring, officials said. If unhealthy levels develop, an alert will be posted on the forecast page of the Department of Air Quality website.
Smoke contains small dust particles and other pollutants that can aggravate respiratory diseases.
Ozone is a gas that occurs naturally in the upper atmosphere, but at ground level it is a key ingredient of urban smog. Ground-level ozone can build up in the afternoon because of strong sunlight, high temperatures and pollutants from automobiles and other sources, including wildfires.
Unhealthy doses of ground-level ozone can reduce lung function and worsen respiratory illnesses such as asthma or bronchitis. Exposure to ozone also can induce coughing, wheezing and shortness of breath, even in healthy people.
When ozone levels are elevated, everyone should limit strenuous outdoor activity, especially people with respiratory diseases, officials said.
A seasonal advisory for ground-level ozone is in effect through September.
To reduce ground-level ozone, officials recommend the following:
• Fill up your gas tank after sunset.
• Plan errands so they can be done in one trip.
• Try not to spill gasoline when filling up, and don’t top off your gas tank.
• Keep your car well maintained.
• Use mass transit or carpool.
• Don’t idle your car engine unnecessarily.
• Walk or ride your bike whenever practical and safe.
To reduce the effects of smoke and dust, the department recommends:
• If you work outdoors, consider wearing a painter’s mask or surgical mask. This will help reduce your exposure to dust and particulates.
• Limit outdoor exertion. Exercise, for example, makes you breathe heavier and increases the amount of particulates you are likely to inhale.
• Keep windows closed. Run your air conditioner inside your house and car. Your air conditioner filters out dust and particulates.
• Consider changing your indoor air filters if they are dirty.