Implications of the new ozone National Ambient Air Quality Standards for compliance in rural areas

The U.S. Environmental Protection Agency (EPA) has recently promulgated new National Ambient Air Quality Standards (NAAQS) for ozone (O-3). The new st andard is based on an 8-hour average O-3 concentration instead of a 1-hour average, as was the previous standard. Analysis of O-3 concentrations measu red at rural sites in the eastern United States in the Aerometric Informati on Retrieval System (AIRS) network, the Southern Oxidant Study's Spatial Oz one Network (SON), and EPA's Clean Air Status and Trends Network (CASTNet) during 1993-1995 indicates that 30-50% of these sites would have been nonco mpliant under the new standard, as compared with only 2-12% under the old s tandard. These results suggest that the new standard will thus require a ma jor shift in emphasis in the nation's pollution control strategy from an ur ban-centered focus to a more regional emphasis. This in turn will require t he development of a more comprehensive, truly rural air quality monitoring network in coming years.