Association of Human Mortality with Air Pollution of Hong Kong

In this study, we attempted to investigate the general statistical association of air pollution with the cardiovascular and respiratory mortality of the elderly in Hong Kong. Based on six years of measurements including the major air pollutant concentrations (PM10, SO2, NO, NO2, O-3, CO), ambient temperature, and mortality (respiratory, cardiovascular) between 2005 and 2010, correlation analysis was carried out in annual, monthly and weekly time scales. From an annual perspective, it was found that the air pollution species may pose a constant effect on the respiratory and the cardiovascular mortality during the studied period since the elderly mortality rates and the air pollution annual concentrations show obvious constant trends. From a monthly time scale, it was found that NO2 and CO have high positive cross correlation with the respiratory mortality of the following 1 to 2 months. In addition, PM10 and CO also have similar delayed influence on the cardiovascular mortality. Among these four pollutants, only CO was found to exhibit high statistical association in the weekly time scale and it is most related to the cardiovascular mortality of the week after next. Therefore, it was concluded that the effect of air pollution on the elderly mortality of Hong Kong should be cumulative. This study implies that the establishment of weekly or monthly air quality indices is necessary for health implications.