[stevenwoo]

I spend a lot of time in the semi rural areas outside of San Jose/San Francisco and out of fire season in the cold months the smell of burning wood is persistent until temps get well out of the 60's (given the number of valleys/mountains, lots of areas stay cold all day in the shade/fog zone once it gets cold). Even if it's a small percentage, the odor is omnipresent, so the particulate pollution is present to some extent as well from a non scientific sampling.

Wood burning (not even special low pollution devices) is not permitted in new construction in the Bay Area because of how much effect even a small percentage of homes can have on air quality.

[labawi]

Wood burning is a pollution problem only when burned incompletely i.e. improperly. Unfortunately, properly burning solid fuel for home heating is not typical.