Ambient trends of benzene in california from 1990 through 1995

摘要

The California Air Resources Board has for the past six years maintained a routine, canister-based ambient toxics monitoring network in urban areas of California. The ambient record is now extensive enough to evaluate the trend of toxic pollutants within the State. This paper evaluates the trend in benzene at seventeen different sites in major population centers in California between 1990 and 1995. Even when considring measurement variability, a significant downward trend in ambient benzene concentrations has been observed throughout the State with an average reduction of 49 percent during the study period. The paper also presents emissions inventory trends of benzene for the same period whose reduction can be attributed to the vehicle emission controls and clean fuel programs.