The Bay Area's first Spare the Air advisory of the season has been called for Saturday, when unhealthy smog and triple-digit temperatures are predicted in some inland valleys.
The Bay Area Air Quality Management District asks residents to voluntarily limit driving, operation of gas-powered motors and other polluting activities.
The public also is advised to limit strenuous exercise to early morning hours before smog levels peak.
Smog can cause throat irritation and chest pains, trigger asthma, inflame the lining of the lungs and worsen bronchitis and emphysema. Long-term exposure to ozone can reduce lung function.
Contact Denis Cuff at 925-943-8267. Follow him at Twitter.com/deniscuff