Ambient PM2.5 and its components is associated with electrocardiographic abnormalities: Evidence from resource-limited areas

Previous research has shown fine particulate matter (PM_2.5) was related to electrocardiographic (ECG) abnormalities. However, evidence of PM_2.5 and its components with ECG indicators is still lacking, especially in resource-limited areas. This study aimed to explore the aforementioned associations and identify crucial components. This cross-sectional study included a total of 27,483 participants from the Henan rural cohort. Generalized linear models were employed to explore the associations between PM_2.5 and its components with ECG abnormalities. To analyze the Concentration-Response (C-R) relationship, restricted cubic splines (RCS) were implemented. Additionally, the quantile-based g-computation (Q-g quantile) regression was utilized to assess the combined effects of PM_2.5 components and their respective contributions to ECG abnormalities. Upon controlling for confounding variables, a significant association was observed between PM_2.5 and its components with abnormalities of heart rate (HR), QRS intervals and heart rate-corrected QT (QTc) intervals. Most C-R curves exhibited a nonlinear relationship. In Q-g quantile regression, PM_2.5 components were significantly with OR (95 % CI) of 1.16 (1.12, 1.20) for HR, 1.28 (1.24, 1.32) for QRS and 1.06 (1.02, 1.09) for QTc intervals. The weight index shows that OM, NH₄⁺ and BC in PM_2.5 have the largest harm proportion in HR, QRS and QTc intervals, which are 0.51, 0.58 and 0.45, respectively. This study indicates that to address the public health challenges associated with PM_2.5, it is necessary to implement effective interventions and strengthen protection for vulnerable populations. Meanwhile, the causal associations still require verification through longitudinal studies.