Intima-media thickness of the common carotid artery in highway toll collectors

PURPOSE: To assess the effects of exposure to exhaust particles on intima-media thickness of the common carotid artery in highway toll collectors. METHODS: Sixty-one highway toll collectors (HTCs) between 24 and 56 years of age (mean, 36.2 +/- 7.3) and 48 controls between 24 and 64 years of age (mean, 42.6 +/- 10.6) were evaluated with gray-scale sonography to measure intima-media thickness (IMT) of the common carotid artery (CCA). Subgroups were categorized according to duration of exhaust exposure and further divided according to tobacco use. RESULTS: CCA IMT was higher (0.8 +/- 0.2 mm) in HTCs than in the control group (0.6 +/- 0.1 mm; p < 0.001) and remained higher when subgroups with similar smoking habits were compared. In HTCs, IMT was greater when the number of years working in tollbooths was greater (p = 0.023). IMT was lower in HTCs with an exposure duration of < 10 years compared with a duration of 10-20 years (p = 0.017) or > 20 years (p value not significant). CONCLUSION: Air pollution has a widely acknowledged negative effect on humans. This study confirms that exposure to exhaust particles might cause wall thickening of carotid arteries.