RESUMO
The in vitro genotoxic effects of organic and water-soluble fractions of airborne particulate matter (PM10) with the cytokinesis blocked micronucleus (MN) test in human alveolar carcinoma cells A549 were investigated. Samples were collected in three different sites of São Paulo State, Brazil, and fifteen soluble metals and the sixteen EPÁs priority polycyclic aromatic hydrocarbons (PAH) were chemically determined. PAHs prevailing were fluoranthene and benzo(ghi)perylene. In the water-soluble extracts, highest concentration of metals was found for zinc, iron, and copper in all places of collection. Although PM10 concentration in all samples was in the range of 33.5-110.1µg/m3, lower than 120µg/m3 (limit established by São Paulo State's legislation for PM10 in 24h), MN results showed that of the 24 samples analyzed, five organic and seven water-soluble extracts presented a significant increase in MN frequency. The frequency of MN correlates with the total PAH concentration of the three sites investigated, and the concentration of PM10 is correlated with the biological effect in two of them. For the water-soluble fraction, all the sites presented a relation between the PM10 concentration and the MN frequency. Again, the genotoxic response showed a correlation with the total concentration of water-soluble metals in two of the three sites. Our results confirm the importance of the soluble fraction of PM10 to the genotoxic effect of airborne PM even at low concentration of water-soluble compounds. Thus, together with chemical analysis, the implementation of the MN protocol for both organic and water-soluble fraction biological monitoring could be used as a strategy in a routine air-quality monitoring program, complementing other usual analyses for air pollution control and protection of populations.