Cytotoxic effects of air pollutants on mammalian cells in vitro.

Extract and fractions of city smog collected from a heavy industrialized area caused in vitro dose-dependent reduction of cell survival of mouse macrophages and a growth inhibition of human fetal diploid lung fibroblasts. Great differences were observed in both cell systems between the total extract and its different fractions. Cytotoxicity declined in the sequence of total extract followed by fractions of cyclohexane, methanol, propanol and of polycyclic aromatic hydrocarbons. Our results illustrate that samples of city smog contain highly toxic substances for mammalian cells in vitro. Differences in cytotoxicity of particular fractions indicate that toxic agents belong to various classes of chemical substances.