Background: 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 still controversial. Objective: To evaluate the effects of exposure of outdoor workers to different levels of traffic-generated PM2.5 on blood pressure. Design: This is an observational panel study. Participants: 88 non-smoking workers exposed to different concentrations of air pollution were evaluated weekly along four successive weeks. Measurements: In each week, personal monitoring of 24-h PM2.5 concentration and 24-h ambulatory blood pressure were measured. The association between blood pressure variables and PM2.5, adjusted for age, body mass index, time in job, daily work hours, diabetes, hypertension and cholesterol was assessed by means of multiple linear regression models fitted by least squares. Results: Exposure to PM2.5 (ranging from 8.5 to 89.7 mu g/m(3)) is significantly and consistently associated with an increase in average blood pressure. An elevation of 10 mu g/m(3) in the concentration of PM2.5 is associated with increments of 3.9 mm Hg (CI 95% = [1.5; 6.3]) in average systolic 24-h blood pressure for hypertensive and/or diabetic workers. Conclusion: Exposure to fine particles, predominantly from vehicular traffic, is associated with elevated blood pressure in hypertensive and/or diabetic 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 increase of blood pressure. An elevation of 10 µg/m3 in the PM2.5 concentration was associated with increments of 4.2 (CI 95%= [2.8; 5.6]) and 2.8 mmHg (CI 95%= [1.6, 4.0]) in average systolic and diastolic 24-hour blood pressure, respectively. Conclusion: Exposure to fine particles, predominantly from vehicular traffic, was associated with elevated blood pressure in hypertensive workers. Less relevant effects were observed in non-hypertensive workers.

Background: Urban air pollutants are associated with cardiovascular events. Traffic controllers are at high risk for pollution exposure during outdoor work shifts. Objective: The purpose of this study was to evaluate the relationship between air pollution and systemic blood pressure in traffic controllers during their work shifts.Methods: This cross-sectional study enrolled 19 male traffic controllers from Santo Andre city (Sao Paulo, Brazil) who were 30-60 years old and exposed to ambient air during outdoor work shifts. Systolic and diastolic blood pressure readings were measured every 15 min by an Ambulatory Arterial Blood Pressure Monitoring device. Hourly measurements (lags of 0-5 h) and the moving averages (2-5 h) of particulate matter (PM10), ozone (O-3) ambient concentrations and the acquired daily minimum temperature and humidity means from the Sao Paulo State Environmental Agency were correlated with both systolic and diastolic blood pressures. Statistical methods included descriptive analysis and linear mixed effect models adjusted for temperature, humidity, work periods and time of day.Results: Interquartile increases of PM10 (33 mu g/m(3)) and O-3 (49 mu g/m(3)) levels were associated with increases in all arterial pressure parameters, ranging from 1.06 to 2.53 mmHg. PM10 concentration was associated with early effects (lag 0), mainly on systolic blood pressure. However, O-3 was weakly associated most consistently with diastolic blood pressure and with late cumulative effects.Conclusions: Santo Andre traffic controllers presented higher blood pressure readings while working their outdoor shifts during periods of exposure to ambient pollutant fluctuations. However, PM10 and O-3 induced cardiovascular effects demonstrated different time courses and end-point behaviors and probably acted through different mechanisms. (C) 2011 Elsevier Inc. All rights reserved.