The Bay Area's first Spare the Air smog alert for the year has been called for Thursday.
The Bay Area Air Quality Management District announced Wednesday that forecasted high temperatures and low winds will generate unhealthy ozone accumulation, or smog, in the area.
During a Spare the Air day, commuters are asked to avoid driving alone and instead take public transit, carpool, walk or bike to work.
Driving less is the most effective way of reducing smog, according to the air district. Smog can cause throat irritation, congestion, chest pain, asthma and worsen bronchitis and emphysema.
Smog can be particularly harmful for young children, seniors and people with respiratory and heart conditions.
The summer Spare the Air season started on April 28. There is no free transit Thursday as a result of the alert being issued.