Interrelation of Experimental Exposure and Ambient Air Quality Data for Comparison of Ozone Exposure Indices and Estimating Agricultural Losses

摘要

The report evaluates ambient air quality indicators for ozone (O3) and estimates the exposure levels associated with agricultural losses. In support of the U.S. EPA Office of Air Quality Planning and Standards review and evaluation of a secondary National Ambient Air Quality Standard for ozone, the Terrestrial Branch within the Corvallis Environmental Research Laboratory investigated alternative exposure indices for characterizing the adverse effects of ozone on agriculture, using experimental data from the National Crop Loss Assessment Network program. Scientific and technical information on ozone and its effects on vegetation, natural ecosystems, natural and artificial materials, and human welfare necessitates a secondary standard that adequately describes the temporal variations of exposure and their effects on plant production and correlates well with short- and long-term exposures. The identification of an appropriate ozone standard that protects against crop yield losses proceeds along two lines: regression analysis of plant response data against various exposure indices to determine indices that best depict biological response, and ambient air quality analysis of ambient O3 data to identify indices that correlate well with various exposure patterns.