Association between long-term air pollution and increased blood pressure and hypertension in China.

Several studies have investigated the short-term effects of ambient air pollutants in the development of high blood pressure and hypertension. However, little information exists regarding the health effects of long-term exposure. To investigate the association between residential long-term exposure to air pollution and blood pressure and hypertension, we studied 24 845 Chinese adults in 11 districts of 3 northeastern cities from 2009 to 2010. Three-year average concentration of particles with an aerodynamic diameter ≤10 µm (PM 10 ), sulfur dioxide (SO 2 ), nitrogen dioxides (NO 2 ), and ozone (O 3 ) were calculated from monitoring stations in the 11 districts. We used generalized additive models and 2-level logistic regressions models to examine the health effects. The results showed that the odds ratio for hypertension increased by 1.12 (95% confidence interval [CI], 1.08–1.16) per 19 μg/m 3 increase in PM 10 , 1.11 (95% CI, 1.04–1.18) per 20 μg/m 3 increase in SO 2 , and 1.13 (95% CI, 1.06–1.20) per 22 μg/m 3 increase in O 3 . The estimated increases in mean systolic and diastolic blood pressure were 0.87 mm Hg (95% CI, 0.48–1.27) and 0.32 mm Hg (95% CI, 0.08–0.56) per 19 μg/m 3 interquartile increase in PM 10 , 0.80 mm Hg (95% CI, 0.46–1.14) and 0.31 mm Hg (95% CI, 0.10–0.51) per 20 μg/m 3 interquartile increase in SO 2 , and 0.73 mm Hg (95% CI, 0.35–1.11) and 0.37 mm Hg (95% CI, 0.14–0.61) per 22 μg/m 3 interquartile increase in O 3 . These associations were only statistically significant in men. In conclusion, long-term exposure to PM 10 , SO 2 , and O 3 was associated with increased arterial blood pressure and hypertension in the study population.