Correlation between on-line PAH detection in airborne particle samples and their bacterial genotoxicity.

The photoelectric aerosol sensor (PAS) is a technique suitable for on-line monitoring of particle-bound polycyclic aromatic hydrocarbons (PPAHs). Although this is a very fast and inexpensive technique, it does not measure individual PAH species but gives a measure of the total amount of PPAHs. Because of the suitability of this sensor for air-pollution screening, it is desirable to know whether a correlation exists between the PPAHs detected with this method and the biological relevance of the respective particle samples. To test the DNA damaging potential of the organic fraction of collected particles, the umuC test with Salmonella typhimurium TA1535/pSK1002 was used. The primary source for particle sampling was a stationary diesel engine, but samples from a parking garage and two locations in the city of Zürich have also been included. The total mass of PPAHs as determined by the PAS was plotted against the induced genotoxicity. This resulted in a linear correlation (r2 = 0.82), indicating that the PAS detects biologically relevant PPAHs.