SHORT-TERM AIR POLLUTION EXPOSURE AND MEASURES OF ARTERIAL STIFFNESS AND CENTRAL HAEMODYNAMICS IN HEALTH YOUNG ADULTS

Abstract

Objective: The practice of outdoor physical exercise is increasingly present in modern societies, as the increasing levels of health literacy corresponds to greater awareness about the positive impact of physical activity. Notwithstanding, the exposure to polluted urban environments during outdoor activities may have deleterious biological effects that should not be overlooked. In particular, the effects of exposure to air pollution in vascular function has been reported in several studies, even though the current evidence is still inconsistent. Objective: To study the effect of outdoor short-term exposure to air pollution in arterial stiffness and central haemodynamics in healthy young adults. Design and method: Twenty young and healthy participants (20 and 25 years) were enrolled in an observational study. Participants performed a mild outdoor walk (1 hour duration) in two ecological settings: green environment (control) and urban environment (experimental). The activities were performed in random order and with at least two weeks interval. Carotid-femoral pulse wave velocity was measured with the Complior device at baseline and at the end of the outdoor walk. Pulse wave analysis (PWA) was performed at baseline and with 15 minute intervals during the outdoor walk with the Mobil-o-Graph device. Air pollution was measured with appropriate devices, including ambulatory measurements of particulate matter (PM). Results: As expected, significant differences were observed in the measures of air pollution between control and experimental settings for all the major air components, particularly for PM1.0, PM2.5 and PM10 (mean difference, respectively, 18.71 ± 2.18 μg/m3, 19.53 ± 2.19 μg/m3 and 26.32 ± 2.66 μg/m3; p<.001). PWV was significantly higher after the exposure in the experimental setting (mean increase of 0.2 ± 0.02 m/s; p<.001), with no variation occurring in the control situation. Also brachial and central blood pressure (BP) depicted greater magnitude of increase during the outdoor walk in the urban setting, as compared with the green environment. Conclusions: Short-term exposure to air pollution during an outdoor walk was shown to be associated with arterial stiffness. The deleterious association of air pollution with vascular function is further buttressed by its hemodynamic impact, particularly increasing brachial and central BP.