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

Background: Long-term exposure to fine particulate matter (PM2.5 or FPM) may cause adverse effects on cardiovascular diseases. However, evidence that whether improved air quality can decrease blood pressure (BP) in humans is still needed from a large population study. Methods: Our study aimed to investigate the association of population ambient PM2.5 exposure with the blood pressure (BP) changes in China with implementing the Action Plan on Air Pollution Prevention and Control. A total of14,080 participants who had at least two valid visits were adopted from the China Health and Retirement Longitudinal Survey (CHARLS) during 2011–2015. Their long-term PM2.5 exposure was assessed at the geographical level of a regular 0.1° × 0.1° grid over China. A mixed-effects regression model was used to assess their associations. The robustness and homogeneity of the association were tested via sensitivity analyses. Results: The results revealed that each reduction 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 of systolic BP (SBP) and 0.50 (95% CI: 0.25–0.75) mmHg of diastolic BP (DBP), respectively. A robust association was observed between the long-term reduction of PM2.5 and decreased BP in the middle-aged and elderly population in China. These findings were further confirmed by a non-linear regression model. Conclusions: We concluded that air pollution control for PM2.5 can obviously promote vascular health. Our study provided robust scientific support for making the air pollution control policies.