Motor vehicle traffic and cardiovascular mortality in male adults

To assess the association between indicators of exposure to motor vehicle-related air pollution and cardiovascular mortality in male adults.

Information on roads and traffic volume for the year 2007 in the city of São Paulo, Southeastern Brazil, was obtained from the local Traffic Engineering Division. Data on mortality from cardiovascular diseases among men aged >40 years in 2005 were obtained from the mortality database of the city of São Paulo. Socioeconomic data from the 2000 Population Census and information on location of health care units were also collected. Exposure was assessed by road density and traffic volume for each geographic unit (administrative districts). Spatial regression (α= 5%) between these indicators of exposure and standardized mortality rates from cardiovascular diseases were estimated. The models were adjusted for socioeconomic variables, number of health care units in the districts and spatial autocorrelation.

It was found a modest correlation between road density and traffic volume (r² = 0.28). The central districts had the highest road densities. The spatial regression model of road density showed an association with mortality from cardiovascular diseases (p = 0.017). No association was found in the model of traffic volume. The socioeconomic variable was statistically significant in both models of road and traffic volume.

The association between mortality from cardiovascular diseases and road density is consistent with literature data. Further individual-level epidemiological studies should be performed using more accurate methods for the assessment of exposure.