Clark County Department of Air Quality (DAQ) has issued an advisory today, Aug. 17 through Friday, Aug. 19, for potentially elevated levels of ozone and smoke due to the Bluecut Fire wildfire burning near the Cajon Pass in Southern California. Air Quality officials say smoke is made of small dust particles and other pollutants that can aggravate respiratory diseases and contribute to ground-level ozone formation.

At this time, “unhealthy for sensitive groups” levels of ozone and particulate matter are not occurring. People who may be most sensitive to elevated levels of ozone and fine particles include individuals with respiratory problems, cardiac disease, young children or senior citizens. Clark County Air Quality officials will continue to monitor conditions and will post an update on the forecast page of the DAQ website. The website also contains data on current and past conditions. A link to the forecast page is: 


New Ozone Standard & Seasonal Advisory: The U.S. Environmental Protection Agency adopted a new standard for ozone in Oct. 2015 at an eight-hour average of 70 parts per billion (ppb). A part per billion is the equivalent of a drop in an Olympic size swimming pool. Clark County met the previous standard at 75 ppb but is expected to struggle with complying with the new, lower standard, especially during the spring and summer months in the Las Vegas Valley. A seasonal advisory for ozone pollution is in effect from April through September, meaning that observed levels could reach the level of the standard. Alerts are issued when unhealthy levels of ozone for sensitive groups are occurring or are imminent.

What is Ozone? Ozone is a gas that occurs naturally in the upper atmosphere and protects earth from the sun’s harmful ultraviolet rays. At ground level, ozone is a key ingredient of urban smog during the hottest months of the year in Clark County. Ground-level ozone can build up during the afternoon hours due to a combination of several factors, including strong sunlight, hot temperatures, and pollutants from automobiles and other sources such as transport, wildfires and fireworks. 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. If you are experiencing breathing difficulties or medical conditions that you think are related to air quality, see your doctor.


The following tips help reduce the formation of ground-level ozone:

  • Use mass transit or carpool.
  • Plan errands so they can be done in one trip.
  • Keep your car well maintained.
  • Don’t idle your car engine unnecessarily.
  • Walk or ride your bike whenever practical and safe.
  • Turn off lights and electronics when not in use. Less fuel burned at power plants means cleaner air.
  • Consider low-maintenance landscaping that uses less water and doesn’t require the use of gas-powered lawn tools to maintain.
  • Limit the use of outdoor fireplaces, grills and fire pits, particularly during daytime hours.
  • Try not to spill gasoline when filling up and don’t top off your gas tank.
  • Fill up your gas tank after sunset.

About Smoke and Particulates

Smoke and dust are forms of inhalable air pollution called particulate matter or PM, which aggravates respiratory diseases. In addition to staying indoors, other suggestions for avoiding dealing with smoke and particulates include:

  • Limit outdoor exertion – exercise makes you breathe heavier and increases the amount of particulates you may inhale.
  • Keep windows and doors closed. Run your air conditioner inside your house and car. Air conditioning filters out dust and particles.
  • Change your indoor air filters if they are dirty.
  • Consult your physician if you have a medical condition that makes you sensitive to air quality conditions.

Clark County is a dynamic and innovative organization dedicated to providing top-quality service with integrity, respect and accountability. With jurisdiction over the world-famous Las Vegas Strip and covering an area the size of New Jersey, Clark is the nation’s 13th-largest county and provides extensive regional services to more than 2.1 million citizens and 45 million visitors a year. Included are the nation’s 8th-busiest airport, air quality compliance, social services and the state’s largest public hospital, University Medical Center. The County also provides municipal services that are traditionally provided by cities to about 954,000 residents in the unincorporated area. Those include fire protection, roads and other public works, parks and recreation, and planning and development.