ABSTRACT
During the last 20 to 30 years, concern over the possible health implications of human exposure to certain major gaseous pollutants has led to widespread, systematic measurements of their concentrations in ambient outdoor air. Additionally, a great deal of information now exists on the emissions, atmospheric transformations, and ultimate fates of such "criteria pollutants" as nitrogen dioxide. 1 Until recently, however, relatively little attention was focused on the levels and potential health impacts of N02 in indoor air environments.
