Table 14. Effects of environmental factors on blood pressure in different studies.

Study name	Time	Age, yrs	Sample size	Findings
PAU: provincial administrative unit.
Survey in 8 PAUs	2007–2010	≥ 50	12,665	Each 10 μg/m3 increase in ambient PM2.5 corresponded to a 1.30 mmHg increase in SBP, a 1.04 mmHg increase in DBP, and a 14% increase in the risk of hypertension
Nationwide cross-sectional study	2011–2012	35–100	13,975	An IQR increase of 41.7 μg/m3 in PM2.5 was associated with a 0.60 mmHg increase in SBP and a 11% increase in the risk of hypertension
CHARLS	2015	≥ 45	20,927	PM2.5 was a risk factor for hypertension, with an OR of 1.063 for women and 1.048 for men
CHS	2012–2015	≥ 18	417,907	Every 10 ℃ increase in ambient temperature was related with a 0.74 mmHg and 0.60 mmHg decrease for SBP and DBP, respectively