Abstract |
Ambient O3 produces significant impacts to crops across the United States. Field studies have moved from characterization of O3 foliar injury symptoms to quantification of yield losses using open-top chambers in order to develop O3 exposure-yield loss functions. These loss functions, in conjunction with ambient O3 exposure and crop distribution data, have been used to predict a current 14% yield loss (for the years 1982-1987) for major U. S. crops. Yield losses would still occur even if all U.S. sites would attain the current secondary National Ambient Air Quality Standards. It is apparent therefore, that the form and level of the current standard is not protective of crop production. |