Ambient Fine Particulate Matter Exposure and Blood Pressure: Evidence from a Large Chinese Multiple Follow-Up Study.

This study aimed to investigate the association of ambient PM2.5 exposure with blood pressure (BP) at the population level in China.A total of 14,080 participants who had at least two valid blood pressure records were selected from the China Health and Retirement Longitudinal Survey during 2011-2015. Their long-term PM2.5 exposure was assessed at the geographical level, on the basis of a regular 0.1° × 0.1° grid over China. A mixed-effects regression model was used to assess associations.Each decrease of 10 μg/m3 in the 1 year-mean PM2.5 concentration (FPM1Y) was associated with a decrease of 1.24 [95% confidence interval (CI): 0.84-1.64] mmHg systolic BP (SBP) and 0.50 (95% CI: 0.25-0.75) mmHg diastolic BP (DBP), respectively. A robust association was observed between the long-term decrease in PM2.5 and decreased BP in the middle-aged and older population. Using a generalized additive mixed model, we further found that SBP increased nonlinearly overall with FPM1Y but in an approximately linear range when the FPM1Y concentration was < 70 µg/m3; In contrast, DBP increased approximately linearly without a clear threshold.Efficient control of PM2.5 air pollution may promote vascular health in China. Our study provides robust scientific support for making the related air pollution control policies.