Figure 2. ORs for risks of arrhythmias by the level of exposure to 12‐month PM₁₀ and PM_2.5 concentration.

(A) OR for PM₁₀ exposure; (B) OR for PM_2.5 exposure. PM_2.5 (particulate matter with an aerodynamic diameter of ≤2.5), PM₁₀ (particulate matter with an aerodynamic diameter of ≤10). The dose‐response curve was calculated using restricted cubic splines with knots at the 5th, 27.5th, 50th, 72.5th, and 95th percentiles of the distribution of 60‐month PM₁₀ concentrations. The reference exposure level was set at the 10th percentile of the distribution of 12‐month PM₁₀ concentrations (47.7 μg/m³) and 12‐month PM_2.5 concentrations (23.2 μg/m³). ORs were adjusted for age (continuous), sex (men or women), study center (Seoul or Suwon), year of visit (continuous), education level (no education, elementary school, middle school, high school, technical college, university, or more), systolic blood pressure (continuous), smoking status (never, current, former), height (continuous), weight (continuous), alcohol consumption (none, moderate, or excessive), physical activity (none, <3 times per week, or ≥3 times per week), and history of diabetes mellitus (yes or no) and history of hypertension (yes or no).