This study has documented that ozone continues to be an important air pollutant, potentially causing serious impact on plants growing near urban areas where concentrations reach high levels. This information could contribute to the impetus for change in the national secondary ozone standards under the U.S. Clean Air Act and could contribute to individual decisions to personally decrease vehicular emissions.
impact statement issue
Ozone reaches high enough concentrations to cause visible foliar injury in sensitive plants every summer in Suffolk County, the most important agricultural county in New York. While regulations have resulted in a reduction in vehicular emissions, which are an important source of precursors for the formation of ozone by the action of UV radiation, there has been an increase in the number of vehicles.
Ozone is more toxic to plants than other air pollutants. Injury includes stippling and bronzing, which can lead to leaf death. Leaves without acute injury may also die prematurely because ozone induces accelerated senescence of leaves that involves many of the genes involved in natural senescence. It was not known how much the effect this injury from exposure to ambient ozone could have on the productivity of plants. In addition to growers, this information would be useful for the U.S. EPA and other agencies responsible for establishing regulations pertaining to air pollutants and national ambient air quality standards.
impact statement response
Research has been conducted to determine the impact on plants of exposure to naturally-occurring ozone. Two plant systems developed to address this question were used. These systems consist of bean lines and clover clones differing in sensitivity to ozone that have similar growth rates in the absence of ozone stress.
Data have been shared with other scientists in the U.S. also investigating how ozone exposure is related to degree of injury and impact on plant productivity. Results from this project also were shared through newsletter articles and presentations with other interested people, including growers, teachers, students, Master Gardeners, members of the Long Island Botanical Society, and the public at large.
impact statement summary
Comparing ozone-sensitive and tolerant snap bean lines exposed to ambient ozone during their growth revealed that this air pollutant every year causes severe injury to leaves of a sensitive plant and substantially reduces yield. This project has been under way since 1997 in the most important agricultural county in New York. Yield was as much as 62 percent lower for the sensitive line compared to the tolerant line.
