The aim of present study is to evaluate whether traffic policemen exposed to urban pollutants and possible psycho-social stressors could be at risk of alterations on plasma insulin-like growth factor (IGF-1) levels compared to a control group. Out of a population of 395 Municipal Police employees, the subjects with principal confounding factors (cigarette smoking habits, drinking habits, oral contraceptives being taken, use of paints, solvents and pesticides) were excluded from the study. The remaining traffic policemen were matched with those not exposed by sex, age and length of service; 49 traffic policemen (22 men and 27 women) with outdoor activity exposed to urban pollutants and 49 not exposed subjects (22 men and 27 women) with indoor activity were included in the study. The plasma levels of IGF-1 resulted significantly higher in the male and female traffic policemen compared with control subjects (respectively P<0.001; P<0.001). The authors hypothesise that occupational exposure to chemical stressors, that may interact with possible psycho-social stressors, could cause an alteration on IGF-1 levels in traffic policemen.