Exposure to PM2.5 from traffic-related air pollution (TRAP) can cause health risk among residents in the urban area. Those who work outdoors are vulnerable to TRAP. PM2.5 from TRAP contain various carcinogenic and mutagenic compounds that can cause genotoxicity to human health. This study indicated that exposure to the higher level of PM2.5 in the urban areas had exhibited an increased in the formation of micronucleus (MN) among respondents. Traf- fic policemen experienced a high concentration of PM2.5 that lead to higher MN frequency compared to the office workers.