Air quality is forecast to be unhealthy for a second day in a row in the Bay Area today, prompting another Spare the Air alert for Sunday by the Bay Area Air Quality Management District.
The alert means that air quality is expected to be poor and residents are advised to reduce driving and avoid outdoor activities during the hottest parts of the day.
Sunday's smog alert is the ninth of 2012.
Residents in Pleasanton and the Tri-Valley are advised to be particularly mindful of ozone pollution, officials said. The alert often coincides with warm weather but other factors contribute to poor air quality, officials said.
Ozone can cause throat irritation, congestion, chest pain and inflammation of the lining of the lungs. Those with asthma, bronchitis and
emphysema are especially vulnerable, as are young children, seniors and those with respiratory and heart conditions.
Residents are asked to avoid driving on Spare the Air days and find alternate transit options, including biking, carpooling or taking public transit.
There is no free transit offered, and a no wood-burning ban is in place.
Sunday's forecast includes temperatures reaching into the upper 90s and lower 100s in the Tri-Valley and into the 70s and lower 80s along the coast as part of a rapid warm-up expected in the area through Tuesday, according to the National Weather Service.