Urban and regional ozone air quality: Issues relevant to the automobile industry

Of the six criteria pollutants for which National Ambient Air Quality Standards (NAAQS) have been established in the U.S., ozone has been the most difficult to control. This report assesses the technical issues and control measures relevant to the ozone air quality standard, including health and welfare effects, the effect of past control efforts, the current understanding of ozone‐precursor relationships, Federal and California attainment strategies, and implications of the 1990 Clean Air Act Amendments and California clean air programs. Despite progress in reducing volatile organic compounds (and oxides of nitrogen) emissions over the last 2 decades, improvement in ozone air quality has been slow. It is clear now that in the worst areas even the most costly and stringent of all available control measures will not lower emissions levels sufficiently to meet the ozone air quality standard. A central issue is how rapidly to proceed to reduce ozone levels, i.e., how to balance the urgency of attaining the ozone standard against the difficulty of attaining it.