Systematic review of the literature regarding the risk of mortality, cancer and cardiovascular diseases in professional drivers

BACKGROUND: Possible ill- health effects of exposures incurred by professional drivers have been reported by several studies with more or less statistically significant results, and continue to be debated in the medical literature. The aim of the present study was to review the existing literature regarding the association between working as a professional driver, mortality, cancer and cardio-vascular diseases. METHODS: The authors considered studies published until May 2012. The literature review was conducted by searching PubMed and EMBASE and using the following research entries: "professional drivers", "mortality", "cancer", "cardiovascular diseases", "health risks", "air-pollution" and "urban air". RESULTS: Of 1,497 studies reviewed, 25 were included in the final analysis. Nine studies were found assessing mortality. Of these, one study indicated that professional drivers had a significantly increased risk for all- cause mortality compared to the general population (Standardised Mortality Ratio, SMR=1.15); five studies indicated a significantly higher risk of lung cancer mortality (SMR ranged 1.16 and 2.12). Seven studies evaluating cardio-vascular diseases focused on myocardial infarction. These reported a higher risk in professional drivers with respect to controls, with crude Odds Ratios (OR) between 1.66 and 3.3, Relative Risks (RR) ranging from 1.19 to 1.6. In five of the above studies, potential confounders were considered. Five of 11 studies reported a statistically significant increased risk of lung cancer in professional drivers with respect to the general population or to other workers, with ORs included between 1.21 and 1.85, and RRs between 1.2 and 1.4. CONCLUSIONS: The reviewed studies had many limitations, such as poor exposure assessment and lack of information on relevant confounders. In addition, heterogeneity in the studies led to problems in summarizing the results. Despite this, study findings suggest the existence of an association between this professional activity and risk for lung cancer and cardiovascular diseases.