[The impact of ambient fine particulate matter on the blood pressure of an urban population in Shanghai, China: a panel study].

OBJECTIVE: To investigate the impact of particulate matter 2.5 (PM2.5) on the blood pressure of urban residents in Shanghai, China.

METHODS: A panel study was conducted from May 27(th) to June 5(th) 2014 in a cohort of 30 adults in an urban community. Participants were 50-80 years old, had lived in the community for at least 5 years, and had a good health status. Key exclusion criteria were current smoking, smoking during the last 3 years, passive smoking, alcohol consumption, and severe cardiopulmonary disease. A total of 28 participants were eligible. Information on demographic characteristics, including of age, sex, height, weight, education, income and chronic comorbidities were collected. Participants were requested to have six weekly blood pressure measurements. Real-time concentrations of PM2.5 and gaseous pollutants were obtained from a nearby air quality monitor during 40 d. Pearson correlation was applied to analyze the correlation between PM2.5 and SO2, NO2, CO and O3. Linear mixed models were applied to analyze the association between PM2.5 and blood pressure, after controlling for time-related trends, day of the week, mean temperature, relative humidity and individual characteristics.

RESULTS: The mean systolic and diastolic blood pressure was (124.0±15.0) mmHg (1 mmHg=0.133 kPa) and (74.0±7.7) mmHg, respectively. At 24 h before blood pressure measurement, the mean PM2.5, SO2, NO2, O3 and CO concentration were (8.3±4.9), (46.6±12.9) , (79.2±27.4) μg/m(3) and (0.8±0.2) mg/m(3). The Pearson correlation coefficient R, between PM2.5 and O3, SO2, NO2 and CO was 0.79, 0.59, 0.34 and 0.45, respectively, with corresponding P-values of <0.001, 0.006, 0.012 and 0.009, respectively. The significant correlation between PM2.5 and systolic blood pressure occurred at lag 1 day, was strongest at lag 3 day, but attenuated thereafter. A 10 μg/m(3) increase in 3-day average concentrations of PM2.5 was associated with changes of 1.86 (95%CI: 0.62-3.09) mmHg in systolic blood pressure and -0.05 (95%CI: 0.59-0.50) mmHg in diastolic blood pressure.

CONCLUSION: Short-term exposure to PM2.5 may significantly elevate the systolic blood pressure of urban residents in Shanghai.