Changing places to study short-term effects of air pollution on cardiovascular health: a panel study

Background Short-term exposure to ambient air pollution triggers acute cardiovascular events. Here, we evaluate the association of exposure to ambient air pollution with two intermediate cardiovascular endpoints: blood pressure and carotid stiffness. Methods In a one-year panel study, we included 20 healthy volunteers (10 male-female couples aged 59–75 years) with air pollution and health parameters measured every two months at their region of residence (Leuven, Belgium) and twice during two ten-day periods in two locations, one with higher (Milan, Italy) and one with lower (Vindeln, Sweden) air pollution levels (220 observations). We measured blood pressure, carotid arterial stiffness, personal exposure to NO 2 , and ambient concentrations of PM 10 , PM 2.5 , and NO 2 . We used linear mixed models to evaluate the associations between the health outcomes and the air pollutants. Results Compared with Leuven, exposure to pollutants was higher in Milan and lower in Vindeln, with the highest contrast for NO 2 (median 20.7 μg/m 3 (IQR:7.4) vs 65.1 μg/m 3 (9.0) and 4.5 mg/m 3 (0.8), respectively). We did not observe significant associations between either systolic or diastolic blood pressure and variations in air pollution. However, we found significant associations between arterial stiffness and 5 day average exposure to the studied pollutants. The strongest associations were observed for PM 10 with carotid distensibility (DC) and compliance (CC) coefficients, and the young elastic modulus (YEM): 4.3% (95%CI:7.0;1.5) increase in DC, 4.7% (95%CI:7.1;2.3) increase in CC and 4.2% (95%CI:1.1;7.3) decrease in YEM for each 10 μg/m 3 decreases in PM 10 . Conclusions Our study suggests that short-term exposure to air pollution results in reductions in carotid elasticity among elderly population.