Use of quantitative epidemiologic data in regulatory approaches to air pollution

Ambient air is a complex mixture containing a variety of substances, some of which are known to be carcinogenic. To develop a homogeneous approach for regulating the emission of these compounds, their individual carcinogenic potential needs to be placed on a comparable scale. The unit risk may be considered as an appropriate measure that condensates dose-response analyses of epidemiologic data into a single, easily interpretable estimate. Given the information on the carcinogenic potency of single compounds, more information on the occurrence of the components and the relation of emissions to specific emittents needs to be considered. In Germany, an approach has been developed that combines different assumptions on complex mixtures for the regulation of the overall risk. This paper outlines some of the principal aspects of the underlying concepts.