Identifying the mechanisms for the effects of air pollution on cardiopulmonary disease in Beijing, China

Large cities in China, including the capital city of Beijing, and their surrounding areas have some of the highest air pollution levels in the world. With over one half of China's population now living in cities, air pollution and air quality are important local and national policy issues. At the same time, China is undergoing changes in health: Deaths in children have come down impressively, and people live to older ages when diseases of the heart and the lung are more common and important. Air pollution in cities is one of the main causes of health problems and disease in China, with especially large effects on the heart and the lung.

We know from research in Europe and North America that air pollution adversely affects human health, but we know little about how and why this happens, and whether air pollution from different sources has more or less effects. Even less is known about what these mechanisms are in China, where air pollution may be from different sources and therefore have different chemistry. This knowledge is important for deciding what the most effective strategies to reduce the health effects of air pollution are. In this research project, leading scientists from China and the United Kingdom will work closely to use modern methods in epidemiology and biological sciences to better understand which components of air pollution affects human health in China, and how these effects occur. This knowledge will be used together with information from our related research projects to identify the most effective ways of protecting human health from air pollution in Chinese cities.

The results of our project will directly impact the translation of the findings across the Megacities-Beijing programme into the policy approaches to mitigate the effects of air pollution in Asian mega-cities. First, the results will help guide technological and economic interventions and policies for reducing air pollution levels and exposure in an effective and cost-effective manner. The pollutant-specific analyses will be essential in identifying which pollutants are most toxic. Because different air pollution sources differentially emit various pollutants, this knowledge can help identify the most important sources of hazardous emissions. For example, the balance of effects between traditional coal/biomass based combustion for domestic and industrial use and traffic related pollutants will be assessed as this will drive the policy response. We will ensure timely and appropriate dissemination of results to policy makers. In particular, the results will be provided to, and integrated in, the Global Burden of Disease Major Air Pollution Sources (GBD MAPS) project, which will focus on the burden of disease attributed to air pollution, specifically that caused by coal burning in China, India and Eastern Europe. In addition, the results will be disseminated to international guidelines (e.g., those from WHO) through participation of investigators as done for our previous studies of air pollution and human health. We will also provide a summary of the results, in easily accessible manners to policy makers in China as well as those in international/bilateral development, health and policy agencies including DFID, WHO, International Agency for Research on Cancer (IARC), and the World Bank. Beyond Beijing and China, these materials will provide lessons for air pollution research and control elsewhere.

China's medical community is well aware of the rising burden of chronic diseases, and its public health community is concerned about the healthcare and economic costs of these conditions, and hence of risk factors such as air pollution that underlie them. We will ensure that our findings reach this important group. Our messages to the health and medical community will emphasise that while the ultimate solution for reducing the disease burden of air pollution is to reduce the emissions of air pollution at sources, finding interim solutions is important for protecting health, especially for vulnerable groups. Our proposed project will reveal biological mechanisms by which air pollution affect the health outcomes, including information about variability in response across individuals. This mechanistic knowledge can help identify susceptible individuals who should receive particular attention directed to reducing their exposures, for example through personal interventions such as home air purification.

Our findings will also reveal particular pathophysiological pathways linking air pollution exposure and adverse health outcomes. This knowledge can be used to develop therapeutic treatments potentially helpful for reducing the harmful impact of air pollution. For example, if oxidative stress plays an important role especially in susceptible individuals, taking antioxidants may be recommended to counter the effects of air pollution. More broadly, our results will contribute to understanding the mechanisms underlying the development of cardiopulmonary diseases, and potentially identify biomarkers for different stages of disease, in relation to environmental exposures. We will disseminate this knowledge in China, in the UK, and globally.

Finally, we will engage with the public throughout the study, in both the UK and in China. As study results become available, we will also work with the Chinese and international media to present information about air pollution for the public. There is enormous interest in the topic among the Chinese public, and timely and accurate information can help shape both social preferences and behaviours.