Are Emissions of Benzo[a]pyrene Expected to Change in California?
Most of the benzo[a]pyrene emissions in California are from combustion sources including vegetative materials burning or combustion-related processes. The staff does not expect an increase in process rates from fuel or vegetative materials burning or from other industrial processes such as oil refining. Because benzo[a]pyrene emissions are directly proportional to the amount of fuel or waste burned or material processed, the staff expects benzo[a]pyrene emissions from fuel combustion or combustion-related processes to remain the same. The benzo[a]pyrene emissions from motor vehicles are directly proportional to the number and types of motor vehicles powered by petroleum-derived fuels. Before the introduction of catalytic converters, mobile sources were the major contributor of benzo[a]pyrene emissions. Most gasoline powered light duty spark-ignition vehicles manufactured after 1974 and operated in the United States are equipped with catalytic converters. As the pre-1974 vehicles grow o
