Exposure to Fine Particulate Matter of Vehicular Origin Is Associated with Increases in Blood Pressure among Hypertensive Outdoor Workers

Hypertension and air pollution are two important risk factors for cardiovascular morbidity and mortality. Although several studies suggest that air pollution has a significant impact on blood pressure, studies on long-term effects are sparse and controversial. Aims: To evaluate the effects of exposure to different levels of traffic-generated PM2.5 on blood pressure in outdoor workers. Methods: 88 non-smoking workers, exposed to different concentrations of vehicular pollution, were evaluated weekly in four successive weeks. At each evaluation, they underwent personal monitoring of 24-hour PM2.5 concentration and 24-hour ambulatory blood pressure. The association between the blood pressure variables and PM2.5, adjusted for age, body mass index, time in job, daily work hours, diabetes or hypertension and cholesterol was assessed by means of multiple linear regression fitted by least squares. Results: Exposure to PM2.5 (ranging from 8.5 to 89.7µg/m3) was significant and consistently associated with an increas...