Abstract |
A field measurement program was carried out in August and September 1972 to investigate the source of high ozone concentrations in Garrett County, Maryland and Preston County, West Virginia. Approximately 11 percent of the hourly ozone concentrations measured at the Garrett County, Maryland airport exceeded the 0.08 ppm National Air Quality Standard. In one episode, the Standard was exceeded for 26 consecutive hours. The mean hourly ozone concentration for the study period was 0.057 ppm and the maximum hourly concentration was 0.119 ppm. High ozone concentrations persisted through the night; the nighttime mean was 0.055 ppm. Nitrogen dioxide and nonmethane hydrocarbon concentrations were at or near background levels throughout the study period. It was concluded that local photochemical synthesis could not account for the observed ozone concentrations in the study area. Analysis of meteorological data indicated that the high ozone concentrations were associated with air masses arriving in the study area after passing over urban-industrial regions. (Author) |