Short-Term Health Effects Of PM2.5 And Black Carbon During Heavy Haze Events In Beijing, China

Abstract

Introduction: In January 2013, severe haze events over northeastern China sparked substantial health concerns. This study was to explore the associations of fine particulate matter less than 2.5μm (PM2.5) and black carbon (BC) with hospital emergency room visits (ERV) during haze in Beijing. Methods: Data on PM2.5, BC, and sulfur dioxide (SO2) concentrations; and meteorologic variables were collected daily from December 1, 2012 to February 28, 2013. Concurrently, daily counts of ERV for respiratory diseases (ICD-10: J00-J99), cardiovascular diseases (ICD-10：I00-I99) and ophthalmologic diseases (ICD-10: H00-H59) were obtained from a Level-3A hospital in Beijing. Pollutant effects were estimated by time-stratified case-crossover analysis in single- and two-pollutant models, controlling for public holidays, temperature and relative humidity. Results: 2323, 541 and 898 cases were collected respectively. Statistically significant associations were observed mainly from lag 0 to lag 1. For an interquartile range (IQR) increases in PM2.5, there was a 18.5% {95% confidence interval (CI): 8.5-28.8%} increase in respiratory ERV (lag 1), a 21.5% (95% CI: 4.7-40.9%) increase in cardiovascular ERV (lag 0), and a 12.3% (95% CI: 0.0-25.8%) increase in ophthalmologic ERV (lag 0). An IQR increase of BC was only associated with a 18.4% (95% CI: 5.2-33.9%) increase in respiratory ERV (lag 1) and a 2.0% (95% CI: 0.4-3.7%) increase in ophthalmologic ERV (lag 0). Estimated effects were consistent after adjusted SO2 in two-pollutant model. The associations between PM2.5 or BC and respiratory ERV were greater for female and 19-45 year-old group, while cardiovascular ERV within 46-60 years old seemed to be more susceptible to PM2.5. Conclusion: Elevated levels of ambient PM2.5 or BC are associated with the increase in hospital ERV for respiratory, cardiovascular and ophthalmologic diseases during severe haze in Beijing, though no association was observed between BC and cardiovascular ERV.