[The concept of environmental pollution for emission control in regulating carcinogenic air pollutants in outdoor air].

The Conference of Ministers for the Environment commissioned a working group of the Länder Committee for Immission Protection to develop a concept of guidelines for the concentration of carcinogenic pollutants in the atmospheric aerosol. Of the large number of substances which have been identified as carcinogenic, seven were selected (arsenic, asbestos, benzene, cadmium, diesel exhaust, polynuclear aromatic hydrocarbons and 2,3,7,8-tetrachlorodibenzo-(p)-dioxin). These substances are emitted into the environment by amounts that are quantitatively of special importance for immission control. There are standardised measuring procedures for controlling them and their toxicological data base permits a quantitative assessment of cancer risk. The quantitative risk assessment by the working group was based on the WHO's "unit risk" model. It was decided that for evolving the guidelines the total cancer risk for all carcinogenic air pollutants be limited while at the same time the possible risk attributed to each individual substance should be reduced according to its contribution to the actual total cancer risk. The synthetic model developed by the working group is explained in detail and the resulting guidelines for an acceptable total cancer risk of 1:1000, 1:2500 und 1:5000 are stated.