Airborne measurements of trace gases and particles in the smoke from a prescribed burn of forest products in the Los Angeles basin show significantly higher emissions of NOX, SO2, and particulate NO3- than do measurements in smokes from the burning of biomass in rural areas. It is postulated that the high emissions are due to the revolatilization of previoulsy deposited pollutants. Implications for pollutant source inventories and the nuclear winter hypothesis are briefly discussed.