抄録
The mutagenic activities of diesel exhaust particles were examined by means of the Ames test. Two types of diesel vehicles (passenger car and truck) were operated on a chassis dynamometer at constant speeds (idling, 20, 40, 60 and 80 km/h) and variable speeds (the ten-mode pattern, the M-15 mode and typical traffic patterns in Tokyo). The exhaust particles were collected on quartz glass fiber filters, which were then extracted with benzene-ethanol mixture (4 : 1, v/v). Each extract was tested by the Ames Salmonella assay. The exhaust particle extracts of both vehicles showed high mutagenic activities on TA 98 and TA 100 strains with and without metabolic activation. The mutagenic activity per km at constant speed driving increased with increase of the speed. Furthermore, acceleration and deceleration caused increases of mutagenic activities per km. The mutagenic activities of the exhausts of both vehicles were positively correlated with particle emission but not with the main gaseous emissions (nitrogen oxides, hydrocarbons, carbon monoxide and carbon dioxide).
