In situ monitoring of mutagenicity of air pollutants in São Paulo city using Tradescantia-SHM bioassay.

The Tradescantia stamen hair mutation assay (Trad-SHM) was employed for assessing the environmental mutagenesis in two areas of São Paulo City. The study sites were defined as follows: 1) Celso Garcia Avenue, an industrial area on the outshirts of the urban center (Belém neighborhood), with an average daily traffic volume of 8.750 vehicles; 2) Doutor Arnaldo Avenue, in downtown area (Pinheiros neighborhood), with a mostly residential and business offices occupation, with an average daily traffic volume of 46,125 vehicles. The negative control (background) site is located in the city of Jaguariúna, 138 km from São Paulo, in an area of low atmospheric pollution. The mutation frequency observed for Belém was similar to the background for clone 4430, whereas plants exposed in Pinheiros showed significant increases in mutation rate. Positive correlation was observed between mutation frequency and the levels of particulate matter in the atmosphere. This indicated a relationship between mutation frequency and the amount of atmospheric pollution present at the exposure sites in São Paulo City, with special reference to vehicular emissions