Abstract: BACKGROUND ＆ AIM: To study the circumstance of traffic air pollution and its effects on the rate of micro-nuclear and sister chromatic exchange and of traffic police in one city and to provide scientific proofs for the management of vehicles and the protection of the occupational group. METERIAL AND METHODS: According to the distribution of the traffic,representative cross roads and a control point were selected and monitored.The monitoring items include the number of inhale,particles(IP),nitrogen oxides(NOx),carbon monoxide(CO) and hydrocarbon(CmHn).The common and health situation of 196 traffic policemen who worked at cross roads and 148 traffic policemen who worked in the office were investigated by means of questionnaires.At the same time,65 traffic policemen who worked at cross roads and 49 traffic policemen who worked in the office whose duration of working exceeded five years were selected by random sample.Micro-nuclear and sister chromatic exchanges in peripheral blood were measured. RESULTS: The concentration of CO，NOx，CmHn and IP in the monitoring point is significantly higher than that in the control point.The concentration of the pollutions has positive correlation with the number of vehicles；Compared with the traffic policemen who worked in the office,the rate of SCE of the traffic policemen who worked at cross roads have significant difference among the different working years,with the working years increasing,the rate of SCE increased；the rate of MN and SCE of the smoking are significantly higher than that of the non-smoking,The rate of SCE of the traffic policemen who worked at cross roads have significant difference between different working years. CONCLUSION: The level of the traffic air pollution of the cross roads in one city has positive correlation with the number of vehicles. The concentration of CO,NOx significantly exceeded the standards；Long-time exposed to traffic air pollution can cause chromatic injury of the traffic policemen who worked at cross road；Smoking can increase the effects of chromatic injury of the traffic air pollution on human bodies.

Key words: traffic pollution, traffic policemen, micro-nuclear, sister chromatic exchang