ABSTRACT

Epidemiological studies may show a relation between air pollutants (e.g., airborne particulate matter) and some adverse health effects (e.g., cardiopulmonary morbidity and mortality). However, an inhalation exposure study is necessary in order to identify the mechanisms triggered by air pollution and causing these health effects. For example, Saunders et al. (2002) found the process of modulation of neurotic behavior in F-344 rats by temporal disposition of benzo(a)pyrene. The existing knowledge on the nature of these mechanisms likely relates to the insidious and multifactorial nature of the underlying pathophysiologic processes (Bartoli et al. 2010). The experimental nature of the inhalation exposure studies conducted on animals and sometimes on people offers a chance for controlled investigations. A well designed laboratory simulating real or predicted exposure is commonly believed to be a reliable source of information on the adverse health effects of inhaling various air pollutants. The results of such experiments, apart from determining the dose-effect relationships, can contribute to the extension of current knowledge. For example, Kleinman et al. (2000) studied toxicity of chemical components of ambient fi ne particulate matter inhaled by aged rats. Another pulmonary toxicity study in rats with PM10 and PM2.5 carried out by Zhang et al. (2011) revealed differential responses related to the scale and composition of these airborne particles.