See here for the other sources: https://www.baaqmd.gov/~/media/files/communications-and-outreach/publications/annual-report/baaqmd-guidebook-08-6-4-09.pdf https

See here for the other sources: https://www.baaqmd.gov/~/media/files/communications-and-outreach/publications/annual-report/baaqmd-guidebook-08-6-4-09.pdf https://www.baaqmd.gov/~/media/files/communications-and-outr... Look on page 7 39% Wood Smoke 12 Cooking 12 Other Mobile Sources 12 Road Dust 7 On-Road Motor Vehicles 6 Combustion: Stationary Sources 5 Industrial/Commercial Processes 3 Construction and Farming Dust 2 Animal Waste 1 Wind-Blown Dust 1 Wildfires Wildfires are basically non-existent in the winter, although the Colorado fire currently doesn't bode well for future California winters.