| Title | Controlled exposure to combined particles and ozone decreases heart rate variability. | ||
| Author | Power, Karron LeGarie; Balmes, John; Solomon, Colin | ||
| Journal | J Occup Environ Med | Publication Year/Month | 2008-Nov |
| PMID | 19001951 | PMCID | -N/A- |
| Affiliation | 1.Lung Biology Center, University of California, Northern California Center for Occupational and Environmental Health, San Francisco, Calif, USA. karronpower@comcast.net. | ||
OBJECTIVE: This experiment was designed to test if controlled exposure to particles and ozone would result in decreased heart rate variability (HRV). METHODS: Five asthmatic adults were exposed for 4 hours to; filtered-air, carbon and ammonium nitrate particles, and particles and ozone. Twenty-minute electrocardiograms were obtained before and after each exposure. RESULTS: Standard deviation of all normal-to-normal beat intervals (SDNN) decreased significantly across particles and ozone exposure compared with across filtered-air exposure (P = 0.01). Changes in SDNN-I (P = 0.04) and normalized low and high frequency (P = 0.02) were also seen across particles and ozone exposure; although these changes may best be characterized as trends given the small sample size. No significant changes in HRV were seen across the filtered-air or particles-only exposures. CONCLUSIONS: The results of this study suggest that combined particle and ozone exposure may decrease HRV in asthmatics. Further investigation is needed to confirm this finding.