Particular Matter Induced Changes in Heart Rate Variability

David Christiani
Harvard School of Public Health
R01ES09860 and P30ES00001

Background: NIEHS has supported much of the research on the adverse cardiovascular health effects of particulate matter air pollution. Fine particles, produced by combustion processes in car engines, power plants, refineries, smelters, and other industries, stimulate anti-inflammatory responses in the lungs and also affect the autonomic nervous system by eliciting stress responses. This is the second recent paper by an NIEHS grantee to demonstrate adverse cardiac effects in response to particulate matter smaller than 2.5 microns (PM2.5) in diameter.

Advance: The study reported here measured a heart rate variability (HRV) using a standardized test known as standard deviation of normal-to-normal intervals. The study subjects were young men and either apprenticing or journeyman boilermakers. They wore PM2.5 and heart rate monitors at work and during non-work hours. Limitations in HRV were observed which were associated with increases in PM2.5 concentration.

Implication: Reductions in HRV have been associated with increased mortality among survivors of heart attacks as well as the general population. These findings demonstrate a relatively rapid-acting component in the mechanism of action of PM2.5 on HRV changes. This finding of detectable differences in autonomic function in this young, health cohort is concerning. Further research is being conducted to elucidate the clinical importance of HRV changes in young, healthy populations that are exposed to PM2.5

Citation: Magari SR, Hauser R, Schwartz J, Williams PL, Smith TJ, Christiani DC. Association of heart rate variability with occupational and environmental exposure to particulate air pollution. Circulation. 2001 Aug 28;104(9):986-91.