Objective To investigate the association between long-term exposure to ambient fine particulate matter (PM_2.5) and the incidence of hypertension in a community-based population in northern China, thus providing evidence for health risk assessment of air pollution.

Methods Utilizing data from the Air, Climate and Health Integrated Monitoring and Intervention Project conducted between 2015 and 2024 in the communities in northern China, a retrospective nested case-control study was conducted. Cases were defined as participants who self-reported first physician-diagnosed hypertension during the study period (case group). Controls were randomly matched to cases in a 1:4 ratio by sex and birth year (1 092, control group). Exposure levels were assessed based on high spatiotemporal resolution ambient PM_2.5 concentrations, with multiple exposure time windows considered. A conditional logistic regression model was employed to examine the association between PM_2.5 exposure and the incidence of hypertension.

Results A total of 273 emerging hypertension cases were observed in this study, with 1 092 matched controls. The 5-year average exposure concentration of PM_2.5 in the case group (78.6 μg/m³) was higher than that in the control group (75.2 μg/m³) (t = 0.009, P < 0.05). Long-term exposure to PM_2.5 was positively correlated with the incidence of hypertension in the community-based population in northern China. For each 10 μg/m³ increase in PM_2.5 concentration, the odds ratio (OR) for emerging hypertension cases was 1.25 (95%CI: 1.07–1.46). After variables such as disease history, smoking, and passive smoking were removed respectively, each 10 μg/m³ increase in PM_2.5 concentration was associated with the OR ranging from 1.23 to 1.28 (all P < 0.05). In sensitivity analyses, the classification of body mass index (BMI) and educational attainment was refined. When BMI was defined as a multinomial categorical variable, the OR was 1.26 (95%CI: 1.08–1.46). Similarly, when educational attainment was defined as a multinomial categorical variable, the OR was 1.26 (95%CI: 1.08–1.46), indicating robust model results. Additionally, overweight/obesity and family history of hypertension were also risk factors for emerging hypertension. Obese individuals had a 1.684-fold higher risk of hypertension compared with non-obese individuals, and those with a family history of hypertension had a 1.520-fold higher risk than those without such a history.

Conclusions Long-term exposure to ambient PM_2.5 is a risk factor for emerging hypertension among community-dwelling residents in northern China, suggesting that measures should be taken to prevent the occurrence of hypertension during heavy pollution periods or when the PM_2.5 pollution level is high.