[Studies on the tumourigenicity of extracts and their fractions of airborne particulates with the subcutaneous test in the XXXX (author's transl)].

@entity2555 @entity19 @entity5 @entity2556 @entity3015
Airborne particulate matter was collected on filters at various times in Duisburg, Duesseldorf, Muenster and in 2 rural areas. After extraction with organic solvents the extract was partly fractionated and analyzed for @entity3015 and 7 other @entity2555 ( @entity2556 ). The carcinogenicity was examined with the subcutaneous test using 7000 @entity19 in total. The amount of extract required was relatively small. Extracts from suspended matter with a @entity3015 content of 0.37 to 1.1 microgram @entity3015 brought about @entity5 rates in the range of 30%. On account of the results the following can be concluded: 1. The total extract of atmospheric particulates results in definite dose-response relationship, when the part of the compounds not belonging to the @entity2556 is rather low. 2. The @entity2556 fractions derived from the suspended matter collected in different cities show the same carcinogenic potency, when they are adjusted to the same @entity3015 level by means of concentration or dilution. 3. The @entity2556 bear the most important share with respect to the carcinogenic potency of an extract from suspended matter. 4. Numerous compounds (polar substances) which are not classed with the @entity2556 are carcinogenic to some extent, partly they are able to inhibit the carcinogenic effect. 5. The dose-response relationship of @entity3015 is strongly leveled off in general when all the substances of an extract are present. That means when the dose of an extract is low, the importance of @entity3015 becomes less. Therefore a fixed ratio concerning the effect of @entity3015 within an extract cannot be given. It has to be examined in particular, which @entity2556 and non- @entity2556 are necessary to analyse in order to describe the carcinogenic effect due to an extract from airborne particulates. Much more attention is to be payed to the polar substances.
