Short-Term Effects of Air Pollution on Heart Rate Variability in Senior Adults in Steubenville, Ohio

Objective: We examined the association between ambient air pollution levels and heart rate variability (HRV) in a panel study of 32 subjects. Methods: We used linear mixed models to analyze the effects of fine particles (PM₂.₅), sulfate (SO⁴²⁻), elemental carbon (EC), and gases on log-transformed standard deviation of normal RR intervals (SDNN), mean square of differences between adjacent RR intervals (r-MSSD), and high- and low-frequency power (HF, LF). Results: An interquartile range (IQR) increase of 5.1 µg/m³ in SO⁴²⁻ on the previous day was associated with a decrease of -3.3% SDNN (95% confidence = -6.0% to -0.5%), -5.6% r-MSSD (-10.7% to -0.2%), and -10.3% HF(-19.5% to -0.1%). Associations with total PM₂.₅ were similar. HRV was not associated with EC, NO₂, SO₂, or O₂. Conclusion: In addition to traffic-related particles, elevated levels of sulfate particles may also adversely affect autonomie function.