Controlled exposure to combined particles and ozone decreases heart rate variability.
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.
Power
Karron LeGarie
KL
Lung Biology Center, University of California, Northern California Center for Occupational and Environmental Health, San Francisco, Calif, USA. karronpower@comcast.net
Balmes
John
J
Solomon
Colin
C
D000328:Adult; D000393:Air Pollutants / Q000009:adverse effects*; D001249:Asthma; D002244:Carbon / Q000009:adverse effects*; D004562:Electrocardiography; D005080:Exercise Test; D005260:Female; D005374:Filtration; D005541:Forced Expiratory Volume; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009566:Nitrates / Q000009:adverse effects*; D010126:Ozone / Q000009:adverse effects*; D052638:Particulate Matter / Q000009:adverse effects*; D010865:Pilot Projects; D011795:Surveys and Questionnaires
D000393:Air Pollutants; D009566:Nitrates; D052638:Particulate Matter; D010126:Ozone; D002244:Carbon; C006568:ammonium nitrate