Estimate of mercury emission from gasoline and diesel fuel consumption, San Francisco Bay area, California

Gasoline samples ( n = 20 ) collected from San Francisco Bay area refineries and service stations had mercury concentrations ranging from 0.08 to 1.4 ng g −1; diesel samples ( n = 19 ) had concentrations of 0.05–0.34 ng g −1. These relatively low levels show little evidence for mercury enrichment or contamination into these fuels from the refining process. Combustion of these fuels in the San Francisco Bay area contributes 0.7–13 kg Hg yr −1 to the environment, with an average of 5 kg Hg yr −1. Assuming the fate of this emission is to the atmosphere, the total flux from the combustion of these fuels represents less than 3% of the total atmospheric emissions in the San Francisco Bay area.