Thursday is a Spare the Air Day, according the the Bay Area Air Quality Management District.
That means residents should avoid outdoor activities during the hottest part of the day, because air quality is unhealthiest then, according to the air district.
Spare the Air Alerts are issued when ozone pollution is forecast to reach unhealthy levels. Ozone, or smog, can cause throat irritation, congestion, chest pain, trigger asthma, inflame the lining of the lungs and worsen bronchitis and emphysema. Long-term exposure to ozone can reduce lung function.
Smog is formed when volatile organic compounds and nitrogen oxides from motor vehicle exhaust, gasoline vapors, industrial emissions and household chemicals combine with oxygen in the presence of heat and sunlight.
Ozone pollution is particularly harmful for young children, seniors and those with respiratory and heart conditions. When a Spare the Air Alert is issued, outdoor exercise should be done only in the early morning hours when ozone concentrations are lower.
Residents can help reduce these levels by carpooling, taking transit, switching to an electric vehicle, biking or walking.
See sparetheair.org or 511.org for more information about commute alternatives.
Residents can check for Spare the Air Alerts by:
* Visiting sparetheair.org
* Calling the toll-free hotline 1-800-HELPAIR (435-7247)
* Signing up for email AirAlerts at sparetheair.org
* Downloading the Spare the Air iPhone or Android app
* Connecting with Spare the Air on Facebook, Google+ or Twitter - follow the hashtag #staalert on Twitter to get Spare the Air Alerts
The Bay Area Air Quality Management District is the regional agency responsible for protecting air quality in the nine-county Bay Area.