Simulation of Airport Air Quality by Box Photochemical and Gaussian Models

Brookhaven National Laboratory has critically evaluated the structure and results of the Stanford Research Institute model (SRI model) for assessing national-level economic impacts of oxidants on plants. In response to inherent weaknesses in the SRI approach, a new model (DAMAGE) was constructed to estimate national-level damage from oxidants for alfalfa. DAMAGE uses actual oxidant measurements and the Oshima dose-response function for alfalfa to estimate effects on yield. Economic loss is then simply calculated by multiplying crop value by percent loss. Estimates of oxidant effects on alfalfa in 1974 were calculated with both DAMAGE and the SRI model. Results of the SRI model closely approach those of DAMAGE when the dose estimate is approximated by the seasonal total of the hourly averages. Other methods of estimating dose in DAMAGE give distinctly higher estimates of economic loss. The lower bound estimates suggest losses equal to $20 million or 4% of the total yield in the counties examined. Upper estimates suggest losses as high as $200 million or a 36% reduction in yield.