ABSTRACT
The nature of individual episode events can vary significantly, depending upon the sources, the chemicals released, the cause of the release(s), and/or the local and regional meteorological conditions. Air pollution episodes have been qualitatively or quantitatively described since 2000 B.C. The most famous of these occurred in London, England; Donora, Pennsylvania; Meuse Valley, Belgium; and New York City, New York. The chapter examines the types of episodes that occurred during the airbourne toxic element and organic substance (ATEOS) project. Each will be characterized by excursions in concentrations of pollutants or indicator species above a standard or alert level. The Newark-Elizabeth ATEOS site dichotomy is consistent with differences in the density of local sources surrounding each site. The general features of the winter and summer episodes that occurred can be used as a guide by individuals who may wish to design future characterization studies, to regulate specific pollutants, or to design acute health effects field studies.
