Bay Area air quality officials have declared Wednesday a winter Spare the Air day, meaning burning of wood and wood products is prohibited.
It's the second Spare the Air day in a row, and the second of the season, which runs from Nov. 1 to Feb. 28. The air forecast for Thursday is also poor.
The 24-hour burn ban is intended to limit the introduction of soot and particulates from wood smoke into the air, where they can contribute to respiratory problems like asthma, bronchitis and lung disease.
The order covers seven Bay Area counties, as well as part of Solano County and the southern portion of Sonoma County.
No wood-based or other solid fuels may be burned indoors or outdoors, except in cases where residences have no other heating source.
Additional information is available at www.sparetheair.org.