Bay Area air will be unhealthy Tuesday, said the Bay Area Air Quality Management District, which issued a Spare the Air Alert for smog.
The district said very high inland temperatures in the 100s and a weak afternoon sea breeze, along with motor vehicle exhaust, will create elevated concentrations of ozone, or smog.
The National Weather Service has declared excessive heat this week for much of California, while much of the Bay Area has been placed under a heat advisory. Residents are being advised to limit afternoon and evening outdoor activities, never leave pets or children in vehicles and to remain hydrated.
Ozone pollution is particularly harmful for young children, seniors and those with respiratory and heart conditions. The agency said people should exercise outdoors only in the early morning hours when ozone concentrations are lower.
Spare the Air Alerts are issued when ozone pollution is forecast to reach unhealthy levels.
Ozone can cause throat irritation, congestion and chest pain. It can trigger asthma, inflame the lining of the lungs and worsen bronchitis and emphysema.
Long-term exposure can reduce lung function.
To find out when a Spare the Air Alert is in effect, residents can register for email AirAlerts at www.sparetheair.org, call 1(800) HELP-AIR.