The Bay Area Air Quality Management District (BAAQMD) established the Spare the Air program to alert people about times when air quality in the Bay Area has reached an unhealthy level. In the summer, ground-level ozone is the pollutant of concern; it accumulates on particularly hot days when there is little wind. In the winter, fine particulate matter (p.m. 2.5) is the pollutant of concern and is usually caused by wood smoke, cold temperatures, and still air in the evening.
Dangers of Poor Air Quality
According to Spare the Air, "Fine particulates can bypass the body's natural defenses, penetrating deeply into the lungs and even passing into the bloodstream. Prolonged exposure to the fine particulates in wood smoke has been linked with aggravated asthma, lung and heart disease, and increased mortality rates."
Wood-Burning Device Regulations
During the winter months, the BAAQMD has made it illegal to burn wood, fire logs, or pellets in indoor or outdoor wood-burning devices during Spare the Air alerts. Alerts will be issued by noon on the day of the alert and will be in place until noon the next day. This is a slight departure from previous winter seasons, where the alerts were in place only during evening hours.