Updated 3:20 p.m.: At 12 a.m. Friday, it will again be legal to burn wood and other solid fuels in Bay Area counties following a 24-hour burn ban issued by the Bay Area Air Quality Management District.
However, according to the district's website, on Friday "wood burning is not illegal, but strongly discouraged. Pollution levels are rising and we are asking Bay Area residents to help prevent air quality from becoming unhealthy by not using their fireplaces and wood stoves."
Another has been declared, beginning at midnight and continuing until midnight Thursday.
The Bay Area Air Quality Management District announced Wednesday that wood burning, both indoors and outdoors, will be illegal all day Jan. 12.
The alert bans the burning of wood, manufactured firelogs or any other solid fuel.
The ban will be in effect in for Alameda, Contra Costa, Marin, Napa, San Francisco, San Mateo, Santa Clara, southern Sonoma and southwestern Solano counties, district officials said.
During winter months, wood smoke is the leading cause of wintertime air pollution in the Bay Area, according to district officials.
Wood smoke contains harmful pollutants, such as soot and carbon monoxide, and toxins such as dioxin, which has been linked to increased cancer rates in adults.
About one-third of the harmful soot in the winter air can be attributed to wood smoke from the 1.4 million fireplaces and wood stoves in the Bay Area, according to the district.
More information about the ban and on whether it is in effect can be found at www.sparetheair.org or by calling 877-4NO-BURN (466-2876).
Those wishing to receive automatic phone calls when a Winter Spare the Air alert is issued can register for the alerts by calling 800-430-1515.
By Bay City News Service; Thursday update by Louisa Hufstader.