Considerations in Setting Standards for Oxides of Nitrogen

Since 1959 the California Department of Public Health has held responsibility for setting standards for ambient air quality and for motor vehicle emissions. The need for standards for oxides of nitrogen involves consideration both of direct effects and effects resulting from participation in photochemical smog reactions. This paper discusses the various effects of concern and describes the department’s program for establishing air quality standards which will become the basis for vehicle emission standards and serve as guides for control of other sources of oxides of nitrogen.