Air district officials extended a Spare the Air alert through Tuesday as wildfire smoke and haze linger in Bay Area skies.
The region has seen air pollution spike in recent days due to car exhaust, high temperatures and smoke.
"Climate change is impacting our region with more frequent wildfires and heat waves leading to poor air quality," said Veronica Eady, senior deputy executive officer of the Air District. "We can all help by driving less to reduce smog and improve air quality when respiratory health is top of mind for us all."
Air pollution can cause throat irritation, congestion, chest pain, trigger asthma, inflame the lining of the lungs and worsen bronchitis and emphysema, air district officials said.
Long-term exposure to ozone can reduce lung function. Ozone pollution, or smog, 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.
Air quality readings are available at baaqmd.gov/highs.
People can find out when a Spare the Air alert is in effect by visiting sparetheair.org, calling 800-HELP-AIR (4357-247), downloading the Spare the Air smartphone app for iPhone or Android devices or connecting with Spare the Air on Facebook, Twitter or YouTube.