A regulation was implemented restricting sulfur to 0.5% by weight in fuel. This lead to a reduction of respiratory symptoms, an improvement in bronchial hyperresponsiveness in children. This study evaluated the short-term effects on mortality of changes in the pollutant mix after sulfur intervention, particularly with changes in PM chemical species; improved the methodology for assessment of the health impact in terms of changes in life expectancy; and developd an approach for analyzing changes in life expectancy. In order to carry out the study, Poisson regression core models were used to assess the short-term effects on mortality as a result of changes in the pollutant mix. In this study, life expectancy loss was small compared to other studies due to a small observation window of three years, whereas other studies did observations for 16 years. PM10 and SO2 exposures were associated with a change in life expectancy. In conclusion, exposure to chemical species is a health hazard. In terms of changes in life expectancy, times-series is a great method to assess short- and long-term effects once you have complete daily air pollution and mortality data over a long period.

We conducted a health impact assessment of the government's proposed new air quality objectives (AQO) in Hong Kong. We based this on the 2005 WHO-AQG and used a lognormal probability density function to model possible changes in annual mean pollutant levels resulting from the new AQO. All of the proposed short-term AQO were based on WHO interim targets (IT) or AQG, but allowed additional exceedances of these single limit values. Compliance with these short-term AQO may reduce the current annual mean concentrations but the distribution proportions exceeding the annual AQG remain high. If the proposed legal limits of AQO are fully exploited by polluters, we estimated the annual number of avoidable deaths at 1860, and avoidable health care events at 5.2 million doctor visits and 92,745 hospital bed-days with a total annual community cost of US$2.6 billion. The proposed AQO may only reduce the current air pollution health impacts by 17% but could achieve 41% reduction if additional exceedances were not permitted. This analysis demonstrates problems arising from the absence of annual limits for some pollutants and the discordance between the short-term and annual AQG, suggesting that revisions based on a lognormal probability model should be considered.

Populations in Asia are not only at risk of harm to their health through environmental degradation as a result of worsening pollution problems but also constantly threatened by recurring and emerging influenza epidemics and pandemics. We assessed the health effects of air pollution and influenza. The excess risk estimates for the short-term effects of air pollution on mortality and hospitalization for broad categories of disease were greater in those ≥65 years than in the all-ages group. The biggest health impacts were seen at the extremes of the age range. In Hong Kong, where air pollution may pose more of a health threat than in North American and European cities, the effects of air pollution also interact with influenza and with residence in socially deprived areas, potentially leading to additional harm. Asian governments should be aware of the combined risks to the health of the population when considering environmental protection and management in the context of economic, urban, and infrastructure development.