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Book Asia’s air: population health after rapid industrialisation Global industrialisation has boosted economic growth, but the consequences for the environment and for population health have been dire. An increase in respiratory and cardiovascular diseases and mortality, particularly in urban areas, has been linked to air pollution worldwide. Hazardous Air Pollutants: Case Studies from Asia (Dong-Chun Shin, CRC Press) is a collection of research papers summarising the current situation in Asia—specifically China, Taiwan, Japan, Indonesia, Malaysia, and South Korea. Each case study offers a country-specific background: socioeconomic, demographic, and geographical context; health effects of and levels of exposure to air pollution; risk assessment and management; and, finally, conclusions and recommendations. These analytical and epidemiological case studies form the first section of the book, with the second section delving into the neurological effects of air pollution, toxic contributions from vehicle emissions, and the big one—climate change. The three major air pollutants are ambient particulate matter with an aerodynamic diameter of 10 μm (PM10), nitrogen dioxide (NO2), and sulphur dioxide (SO2). Fossil fuel combustion is known to contribute substantially to urban air pollution, which is a discernable problem when economic growth is reliant on energy consumption. China is a leading example of a country that has gained in prosperity and wealth, but consequently suffered from a decline in environmental and population health. Each of the countries studied now have national Ambient Air Quality Standards. Ambient air pollution is a major risk factor for population health in China—PM with an aerodynamic diameter of 2·5 μm (PM2·5) is considered particularly dangerous. In the first chapter, on China, Shaowei Wu and Xinbiao Guo note that only a small number of epidemiological studies have indicated an association between PM2·5 and mortality— more so than from the larger particles—but much uncertainty remains about the adverse health effects of ambient PM, owing to its varying sizes and chemical components. They also highlight the scarcity of research on the long-term health effects of air pollution in China— compared with studies done in less-polluted regions such as North America and Europe—which can provide valuable evidence to ensure that air quality guidelines will address the key concerns in China. The respiratory system acts as the first barrier against air pollutants. Wu and Guo list several studies which show that PM2·5 has a strong association with decreased lung function, and suggest a cumulative effect. They also look at toxicological studies that predominately isolate PM2·5 as the most cytotoxic of all particles, and suggest that PM exposure might lead to increased pulmonary and systemic inflammation.
Asian dust (or yellow dust) storms affect many regions in east Asia, particularly during the late winter to spring months. This meteorological phenomenon is caused by dust storms forming dense clouds of fine, dry soil particles, which are largely transported from the deserts of Mongolia and northern China, increasing in toxicity as they pass through heavily industrialised cities. This health hazard is discussed in Chang-Chuan Chan and colleagues’ case study of Taiwan, but the threat is not isolated to this region only, with Japan increasingly affected. The authors reiterate many points raised in Wu and Guo’s chapter on China; however, air pollution levels, population structure, and environmental stressors differ between the two. Studies on the health impact of air pollution—in Taiwan and elsewhere—have mostly focused on short-term exposures and cardiorespiratory effects, showing a decrease in lung function and an increase in morbidity of pulmonary diseases, such as chronic obstructive pulmonary disease, asthma, and pneumonia. Chan and colleagues also discuss industrial sources of air pollutants, as Taiwan hosts what is considered to be the world’s largest coal-fired power plant—not surprisingly reported as a substantial CO2 contributor, even with emission control devices installed. In addition, on Taiwan’s west coast, the No 6 Naphtha Cracking complex is a vast multi-plant area, with oil refineries, petrochemical-related plants, and boiler plants contributing to its major sulphur oxide emissions, and releasing thousands of tons of PM, SO2, nitrogen oxide, and volatile organic compounds. Toru Takebayashi writes about Japan, where air quality might be less hazardous than in its neighbours because the country has reacted rapidly with advanced technologies to stem the threat from industrialisation. In the 1960s, a well documented episode of high SO2 emissions in Yokkiachi in Mie prefecture on Japan’s south coast led to a lawsuit that proved epidemiological causality between, predominately, sulphur oxide emissions and respiratory health problems. In 2011, Katanoda and colleagues did a study to investigate the effects of air pollutants on mortality in Japan, with specific attention to respiratory diseases. The major finding was that lung cancer mortality was significantly associated with SO2, NO2, and suspended PM concentrations. Japan enacted environmental laws to control the levels of air pollution as early as the 1960s. Laws to control emissions have been effective to some extent but each country faces its own unique challenges. Some areas are more prone to atmospheric or climate factors, whereas others face the consequences of urbanisation: population increase, mass power generation, and vehicle emissions. Takebayashi acknowledges that environmental issues
www.thelancet.com/respiratory Published online September 28, 2016 http://dx.doi.org/10.1016/S2213-2600(16)30304-6
Published Online September 28, 2016 http://dx.doi.org/10.1016/ S2213-2600(16)30304-6 Hazardous Air Pollutants Case Studies from Asia Edited by Dong-Chun Sin CRC Press, Taylor & Francis Group, FL, USA, 2016 Pp 185. $139·95 ISBN 978-1466593565 See News Lancet Respir Med 2013; 1: 435
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are no longer confined within borders, and favours a collaborative approach for a regional solution. Indonesia is spread across thousands of coral, volcanic, and tectonic islands, and with overpopulated Java (home to 68% of the country’s population), the country is at risk from both urban and volcanic air pollution. However, the absence of real-time air quality information makes accurate assessments difficult. In their case study of Indonesia, UmarFahmi Achmadi and Rachmadhi Purwana address the natural (volcanoes, forest fires) and anthropogenic (motor vehicles, industry, household sources, smoking) threats. They note that respiratory hospital admissions are continually rising in Jakarta, Java, as a result of severe air pollution. The authors also highlight the threat of indoor air pollution inside the high-rise, air-conditioned buildings which dominate the skylines in major cities. They suggest that poor maintenance of the air conditioning systems, together with physical, biological, and chemical contaminants in the processed wood and fabric used in furniture—such as benzene—create a toxic environment. Slum areas with indoor smoke from cigarettes and the burning of biomass fuels are also major risks to public health in Indonesia’s cities. Indonesia has been slow to respond to the problem of air pollution despite its implementation of the central government’s Blue Sky programme that seeks to control emissions from mobile and stationary sources. The Malaysian Government has shown more foresight and leadership in its management of air pollution, according to Mazura Sahani and colleagues’ chapter covering the “unique nature” of air pollution in Malaysia. The Government developed the Clean Air Action Plan, which also addresses climate change and greenhouse gas emissions. Malaysia’s poor air quality became a cause for concern with a particularly disruptive haze occurring in April, 1983. This seasonal atmospheric pollution occurs almost every year, during the periods of June–September and December–March; the worst episodes can last up to 3 months, with PM concentrations frequently exceeding national ambient air quality standards. Many
areas in southeast Asia are affected, but Malaysia was hardest hit in 1997 when the prime minister declared a state of emergency. Studies have confirmed that during haze episodes, hospital admissions for upper respiratory tract infections, conjunctivitis, and asthma, as well as respiratory mortality, are substantially higher compared with non-haze periods, when overall air quality is at a good to moderate level. Government mitigation plans include cross-border cooperation to implement an early warning system with ongoing monitoring stations in urban and rural areas. The final case study is on South Korea, authored by Shin. He explains that since the Ministry of Environment introduced monitoring of PM10, evidence linking air pollution and mortality has been shown. However, to safeguard public health in the future, more research needs to be carried out to determine for whom and when the risk is the highest so that policy making for intervention control is relevant and effective. However, Shin is optimistic about future reduction of negative health effects with the introduction of total air pollution load management systems, which he describes as an advanced management policy designed to improve the atmospheric environment. He also advocates for new technologies that can measure real-time toxicology variables of air pollution. Data on morbidity and mortality due to air pollution need to be translated into economic loss to demonstrate the financial burden on government budgets. Evidence from scientific studies is imperative, Shin argues, and he advocates further research on sources contributing to composition of PM10 and haze pollution. Health risk analyses, combined with decision-support tools, can help to to manage overall air quality in Asia. He concludes that how air pollution directly affects health is still relatively unknown. In the last three chapters, Changsoo Kim and Jaelim Cho look at brain health—the adverse effects of air pollution on psychiatric disorders, neurodegenerative disease, and neurodevelopmental disorders, particularly those with little known causes. This is followed by Eri Saiakwa and Noelle E Selin’s analysis on how reduction of vehicle emissions will have substantial health benefits, and finally Susan Buchanan and colleagues’ study on the cost of the health burden from coal combustion that is continuing to rise to satisfy the demands of energy consumption worldwide. Hazardous Air Pollutants offers a concise and detailed analysis of current data on air pollution in Asia. Each study has clear objectives—to examine adverse health effects, sources of pollutants, history of interventions, measurement and controls, challenges and successes, the economic burden, and air quality policies. This book undoubtedly provides an expert academic summary of scientific research tackling a problem that we all face in our daily lives—how toxic is the air that we breathe, how much harm is it doing, and what can we do to improve it?
Jules Morgan 2
www.thelancet.com/respiratory Published online September 28, 2016 http://dx.doi.org/10.1016/S2213-2600(16)30304-6