Residential greenness alleviated the adverse associations of long-term exposure to ambient PM with cardiac conduction abnormalities in rural adults.

BACKGROUND

Ambient air pollution was linked to elevated risks of adverse cardiovascular events, and alterations in electrophysiological properties of the heart might be potential pathways. However, there is still lacking research exploring the associations between PM exposure and cardiac conduction parameters. Additionally, the interactive effects of PM and residential greenness on cardiac conduction parameters in resource-limited areas remain unknown.

METHODS

A total of 27483 individuals were enrolled from the Henan Rural Cohort study. Cardiac conduction parameters were tested by 12-lead electrocardiograms. Concentrations of PM were evaluated by satellite-based spatiotemporal models. Levels of residential greenness were assessed using Enhanced Vegetation Index (EVI) and Normalized difference vegetation index (NDVI). Logistic regression models and restricted cubic splines were fitted to explore the associations of PM and residential greenness exposure with cardiac conduction abnormalities risk, and the interaction plot method was performed to visualize their interaction effects.

RESULTS

The 3-year median concentration of PM was 56.47 (2.55) μg/m, the adjusted odds rate (ORs) and 95% confidence intervals (CIs) for abnormal HR, PR, QRS, and QTc interval risk in response to 1 μg/m increase in PM were 1.064 (1.044, 1.085), 1.037 (1.002, 1.074), 1.061 (1.044, 1.077) and 1.046 (1.028, 1.065), respectively. Participants exposure to higher levels of PM had increased risks of abnormal HR (OR = 1.221, 95%CI: 1.144, 1.303), PR (OR = 1.061, 95%CI: 0.940, 1.196), QRS (OR = 1.225, 95%CI: 1.161, 1.294) and QTc interval (OR = 1.193, 95%CI: 1.121, 1.271) compared with lower levels of PM. Negative interactive effects of exposure to PM and residential greenness on abnormal HR, QRS, and QTc intervals were observed (P < 0.05).

CONCLUSION

Long-term PM exposure was associated with elevated cardiac conduction abnormalities risks, and this adverse association might be mitigated by residential greenness to some extent. These findings emphasize that controlling PM pollution and increasing greenness levels might be effective strategies to reduce cardiovascular disease burdens in resource-limited areas.