[Biological effect of fine atmospheric dust extracts. IX. Quantitative cytologic study of the cytotoxic effect of fine atmospheric dust extracts on macrophages].

Macrophages of cell line IC-21 were exposed to extracts and fractions of two samples of city smog (CSE 16 and 17) from the heavy industrialized Rhine-Ruhr-area. Cytotoxic effects of extracts and fractions were analysed in various concentrations and periods of incubation. As cytotoxic parameters were determined frequencies of mitosis and pycnosis of nuclei as well as occurrence of multinucleated giant cells. An increasing dosage of noxae showed a reduction of mitotic rate, a rise of pycnosis of nuclei and of multinucleated giant cells. For both city smog extracts these effects depended on incubation period and concentration of noxae. While the global extract of city smog no. 16 was always more effective than its fractions, with city smog no. 17 the strongest alterations were demonstrable by its cyclohexane-fraction and partly by its methanol-fraction. Based on air volume of collection both samples of city smog revealed a comparable cytotoxic effect. In relation to benzo(a)pyrene-content, however, city smog no. 17 was considerable more cytotoxic than city smog no. 16. These results confirm again cytotoxicity of city smog. It can be assumed that both samples of city smog impair defense mechanisms of the lung.