Assessment of Air Quality and Air Pollutant Impacts in Class I National Parks of California

Sullivan, T.; Peterson, D.; Blanchard, C.; Tannebaum, S.

This report summarizes current and potential future conditions of air quality and air pollution impacts in Class I national parks1 located in California, and recommends monitoring and research activities that could be implemented to acquire critical new data. The subject parks include Joshua Tree National Park (JOTR), Lassen Volcanic National Park (LAVO), Lava Beds National Monument (LABE), Pinnacles National Monument (PINN), Point Reyes National Seashore (PORE), Redwood National Park (REDW), Sequoia and Kings Canyon National Parks (SEKI), and Yosemite National Park (YOSE). The focus of this report is on the effects of pollutants (ozone, sulfur dioxide, nitrogen oxides, particulates, sulfate, and ammonia) on air quality and on selected air quality related values (terrestrial vegetation, aquatic systems, visibility). Other pollutants (e.g., pesticides) are also discussed for specific locations where these pollutants may have potential impacts on natural resources. In general, air quality adjacent to some Class I areas in California is considerably better than in areas of the eastern United States. Air quality in many areas is among the best in the United States, in particular at near-coastal northern locations and in remote sections of the Sierra Nevada and Cascade Mountains. However, southern airsheds on the western slopes of the Sierra Nevada (Sequoia, Kings Canyon (referred to jointly throughout the report as SEKI), and Yosemite National Parks) and in the southeastern deserts (Joshua Tree National Park) experience elevated ozone concentrations and nitrogen deposition, especially during summer months. Other Class I areas throughout the state experience seasonal to chronic periods of poor air quality, especially high ozone. These areas include Pinnacles National Monument and Lassen Volcanic National Park. California is the most populous state in the nation, and vehicular emissions and point sources are concentrated around major population centers. The highest emission source areas of nitrogen oxides and reactive organic gasses (precursors of ozone) are the South Coast, San Francisco Bay Area, and San Joaquin Valley air basins. These emissions are mainly from motor vehicles, with other significant sources of nitrogen from fossil-fueled power plants and of reactive organic gasses from cleaning and surface coatings and solvent evaporation. Sulfur dioxide emissions have been low in California since the early 1980s and do not currently pose a significant concern for Class I areas.

Assessment of Air Quality and Air Pollutant Impacts in Class I National Parks of California

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