SAN FRANCISCO -- The bad air news continues. Another "Spare the Air" alert has been issued for Friday.

It will be the 26th such alert since the tracking season began Nov. 1, making it illegal to burn wood, manufactured fire logs or solid fuels for 24 hours.

The Bay Area Air Quality Management District issued the alert for Alameda, Contra Costa, Marin, Napa, San Francisco, San Mateo, Santa Clara, southern Sonoma and southwestern Solano counties.

An unusually dry, windless winter is leading to the persistent build up of particulates or soot pollution from wood smoke, which can be damaging to those with asthma, bronchitis and lung disease, air officials say.

First-time violators of the ban may be subject to a $100 fine or be given the option of taking a wood smoke awareness class. Subsequent violations will result in fines of $500 or more.

Since new federal standards were adopted in 2006, the district has not had a winter with air quality this bad, officials say. This winter tops the record set under the new standards, two winters ago, in which 15 alerts were issued.

The winter Spare the Air season ends Feb. 28.

Contact Joyce Tsai at 925-847-2123. Follow her at Twitter.com/JoyceTsaiNews.