Real-Time Size-Fractioned Particulate Air Pollution and Blood Pressure Among Healthy Adults: A Repeated-Measure Panel Study

Abstract

Short-term exposure to ambient particulate matter (PM) has growingly been related to blood pressure (BP), but little is known about the relevance of different particle size. To explore the relationship between short-term particle size exposure and BP, a repeated-measure study including 40 healthy college students was conducted. Real-time particle mass concentrations (PMC) and size-specific particle number concentrations (PNC) were collected. Repeated BP measurements were conducted in each subject. Linear mixed-effect models were applied to estimate association of PMC or PNC with BP with adjustment for covariates. Effects on systolic BP, diastolic BP and mean arterial pressure (MAP) weakened with increasing diameter. The most significant associations were observed for PNC0.25-0.40, PMC1 and PMC2.5, and the associations appeared immediately in the first 2 hours and lasted for up to 72 hours after exposure. An IQR change of PNC0.25–0.40 corresponded to increases of 6.17 mmHg (95% CI: 2.86, 9.47) in SBP, 6.30 mmHg (95% CI: 4.19, 8.41) in DBP and 6.25 mmHg (95% CI: 3.97, 8.54) in MAP; for PM1, the corresponding increases were 1.81 mmHg (95% CI: 0.33, 3.30), 2.67 mmHg (95% CI: 1.73, 3.62), and 2.38 mmHg (95% CI: 1.35, 3.42); for PM2.5, the corresponding increases were 1.58 mmHg (95% CI: -0.32, 3.47), 2.86 mmHg (95% CI: 1.63, 4.09), and 2.43 mmHg (95% CI: 1.09, 3.77) 72 h after exposure. Females were more susceptible to these effects. This real-world investigation highlighted effects of short-term PM exposure on BP that depended on particle size and lag patterns among healthy Chinese adults.

Keywords: blood pressure, air pollution, particle size, healthy young adults, repeated-measure study