Today's Spare the Air Day marks the third consecutive day when air quality is expected to be poor in the Bay Area.
High temperatures coupled with bad air quality have prompted the need for another Spare the Air Day, according to air district officials.
On Spare the Air Days, residents are encouraged to drive less and reduce their energy use every day so pollution levels are lower, preventing health alerts when temperatures are high.
There will not be free transit on Wednesday.
“This late seasonal hot spell is expected to create conditions for unhealthy air quality for the third day in a row,” Air District Executive Officer Jack Broadbent said in a statement.
“We’re urging everyone to make clean air choices, such as taking public transportation, reducing energy use, and refraining from using gas-powered lawn equipment, to keep pollution levels down,” he said.
Motor vehicle exhaust, gasoline vapors, industrial emissions and household chemicals contain volatile organic compounds and nitrogen oxides that combine with oxygen in the presence of heat and sunlight to form ground-level ozone, according to the air district.
Breathing ozone can cause throat irritation, congestion and chest pain; and can trigger asthma, inflame the lining of the lungs and worsen bronchitis and emphysema.
Long-term exposure to ozone can reduce lung function. High levels of ozone pollution are particularly harmful for young children, seniors and those with respiratory and heart conditions. Vigorous outdoor exercise should be undertaken only in the early morning hours when ozone concentrations are lower.
The air district issues Spare the Air Alerts whenever air quality is forecast to reach unhealthy concentrations.
The air district recommends residents follow these steps to maintain healthy air quality in the Bay Area:
• Bike to work or around town
• Take public transit
• Work at home or telecommute
• Carpool and link your errands to reduce driving
• Avoid using gas-powered lawn mowers and leaf blowers
• Reduce household energy use
• Don’t use lighter fluid on the barbecue
• Avoid using aerosol spray cleaners, paints and hairspray