Due to an unhealthy level of pollution, the Bay Area is under a spare-the-air alert Saturday, which severely limits what can be burned indoors and outdoors.

The alert issued by the Bay Area Air Quality Management District prohibits burning wood or other solid fuel in fireplaces, wood stoves and inserts, pellet stoves, outdoor fire-pits, or other wood-burning devices all day. The ban is in effect for Santa Clara, San Mateo, Alameda, Contra Costa, Marin, Napa, San Francisco, southern Sonoma and southwestern Solano Counties.

Smoke from wood-burning fires can harm people suffering from asthma, bronchitis and lung disease, and is especially dangerous for children and the elderly.

For more information about the burning ban, visit www.sparetheair.org or call 1-877-4NO-BURN.

Bay Area residents also can call 1-800-430-1515 to register to receive automatic phone calls when a winter spare-the-air alert has been called.

Contact Steve Johnson at sjohnson@mercurynews.com or 408-920-5043. Follow him at Twitter.com/steveatmercnews

Copyright 2012 San Jose Mercury News. All rights reserved.