This cross-sectional type study was conducted between November 2004 and September 2006. In a total of 200 male persons were randomly selected from the heavy vehicle driver population (p=0.08,q=0.92,N=1200, alpha=0.01, d=0.045). In a total of 200 male non-driver persons of the same ages were used as a control g roup. 90 % were reached for the sample. A total of 181 heavy vehicle drivers were included in the study (75 bus and 106 truck drivers).