Abstracts: ISEE 21st Annual Conference, Dublin, Ireland, August 25-29, 2009: Symposium Abstracts
Background and Objective:
Epidemiological studies have demonstrated a consistent increased risk for cardiovascular events in relation to concentrations of ambient pollution. This study is to explore the associations between the heart rate variability (HRV) of the aged people and the air pollution reduction during Beijing Olympic Games in 2008.
Panel study design. Twenty-six persons over 55 years of age with a history of coronary heart disease or myocardial ischemia were recruited as a panel and followed up five times by HRV measure and other related examinations from June to September, 2008. Data on air pollutants and meteorological conditions were collected from local municipal environmental protection bureaux and the meteorological bureau in Beijing. The data were analyzed using linear mixed-effects models.
The ambient concentrations of sulfur dioxide (SO2), nitrogen dioxide (NO2) and particulate matter less than 10 μm in aerodynamic diameter (PM10) decreased by 37.93%, 33.33% and 40.08%, respectively (P < 0.05) during the Olympic Games compared to the average concentrations of last two months. There was a significant improvement in subject's HRV during the Olympic Games compared to control periods (P < 0.05). In single-pollutant mixed-effects models, we found that the reduction in ambient SO2 concentration was significantly associated with improvement of the total power and high-frequency power (HF) of HRV in the panel subjects (P < 0.05). A 10 μm/m3 decrease in SO2 level was associated with 526.74 (95%CI: 298.23, 755.25) ms rises in total power and 198.55 (95%CI: 109.84, 287.26) ms rises in high-frequency power (HF) of HRV, respectively.
The traffic-control measures during the Olympics improved the air quality in Beijing effectively and also improved the HRV level of exposed aged people. It suggests that air pollution reduction could improve the cardiovascular function of susceptible populations.