Mutagenic activity of non-volatile organic matter associated with suspended matter in urban air.

Extracts of atmospheric suspended matter showed a direct mutagenic effect in the Ames test. This effect was increased by metabolic activation. These extracts were separated into an aliphatic, an aromatic and a polar fraction. The aliphatic fraction had no effect, with or without activation; the aromatic fraction showed the greatest mutagenicity with and without activation; the polar fraction was also mutagenic, but its metabolic activation did not enhance the effect. The active compounds in this last fraction could be represented in a significant part by oxygenated derivatives of polycyclic aromatic hydrocarbons.