Effects of short-term increases in personal and ambient pollutant concentrations on pulmonary and cardiovascular function: A panel study analysis of the Multicenter Ozone Study in oldEr subjects (MOSES 2).

BACKGROUND: The cardiovascular effects of ozone exposure are unclear. Using measurements from the 87 participants in the Multicenter Ozone Study of oldEr Subjects (MOSES), we examined whether personal and ambient pollutant exposures before the controlled exposure sessions would be associated with adverse changes in pulmonary and cardiovascular function. METHODS: We used mixed effects linear regression to evaluate associations between increased personal exposures and ambient pollutant concentrations in the 96 h before the pre-exposure visit, and 1) biomarkers measured at pre-exposure, and 2) changes in biomarkers from pre-to post-exposure. RESULTS: Decreases in pre-exposure forced expiratory volume in 1 s (FEV1) were associated with interquartile-range increases in concentrations of particulate matter ≤2.5 µm (PM2.5) 1 h before the pre-exposure visit (-0.022 L; 95% CI -0.037 to -0.006; p = 0.007), carbon monoxide (CO) in the prior 3 h (-0.046 L; 95% CI -0.076 to -0.016; p = 0.003), and nitrogen dioxide (NO2) in the prior 72 h (-0.030 L; 95% CI -0.052 to -0.008; p = 0.007). From pre-to post-exposure, increases in FEV1 were marginally significantly associated with increases in personal ozone exposure (0.010 L; 95% CI 0.004 to 0.026; p = 0.010), and ambient PM2.5 and CO at all lag times. Ambient ozone concentrations in the prior 96 h were associated with both decreased pre-exposure high frequency (HF) heart rate variability (HRV) and increases in HF HRV from pre-to post-exposure. CONCLUSIONS: We observed associations between increased ambient PM2.5, NO2, and CO levels and reduced pulmonary function, and increased ambient ozone concentrations and reduced HRV. Pulmonary function and HRV increased across the exposure sessions in association with these same pollutant increases, suggesting a "recovery" during the exposure sessions. These findings support an association between short term increases in ambient PM2.5, NO2, and CO and decreased pulmonary function, and increased ambient ozone and decreased HRV.