The United States and China are the top two energy consumers in the world. As a consequence, they are also the top two emitters of numerous air pollutants which have local, regional, and global impacts. Urbanization has led to serious air pollution problems in U.S. and Chinese cities; although U.S. cities continues to face challenges, the lessons they have learned in managing energy use and air quality are relevant to the Chinese experience. This report summarizes current trends, profiles two U.S. and two Chinese cities, and recommends key actions to enable each country to continue to improve urban air quality.

In October 2003, a group of experts met in Beijing under the auspices of the Chinese Academy of Sciences, Chinese Academy of Engineering, and National Academy of Engineering (NAE)/National Research Council (NRC) of the National Academies to continue a dialogue and eventually chart a rational course of energy use in China. This collection of papers is intended to introduce the reader to the complicated problems of urban air pollution and energy choices in China.

"Around the world, cities provide plenty of opportunities such as better education, advanced health treatment facilities, better employment, commerce, and trade as compared to rural areas. Therefore, more than half the world's people live and work together in urban communities, and it is projected that by the year 2030, three out of five people will stay in cities. The unrestrained and rapid growth of cities has also brought environmental degradation and causes many serious problems such as worsening of air quality, loss of natural habitat and species diversity, and increased human health risks associated with heat waves, noise and crowding. In most urban areas of developing countries, a variety of harmful air pollutants such as particulate matter, carbon monoxide, nitrogen and sulfur oxides, and polycyclic aromatic hydrocarbons are emitted from a variety of sources, mainly the burning of wood, fossil fuels and vehicular emissions, which adversely affects the health of human beings, animals, and other living creatures. In the urban environment, trees provide many economic, social, and environmental benefits to people, such as aesthetic beauty, improvement of property values, erosion prevention, storm water management, noise reduction, mental health development and crime reduction. In addition, trees help cool the air by shading surfaces that otherwise would absorb the sun's energy and then reradiate it out as heat. Trees also cool the ambient air. Urban trees on average reduce air temperatures on summer days by 2-4 °F, although in some circumstances the cooling effect can be even larger. Trees also sequester carbon, helping to mitigate climate change. The efficiency of atmospheric cleansing by trees in congested cities could be improved by planting more trees other than shrubs or herbs. Generally, avenue trees act as living filters to decrease pollution through absorption, accumulation, and detoxification. Trees remove gaseous air pollutants such as ozone, sulphur dioxide, and nitrogen dioxide mainly by uptake via leaf stomata, although some gases are removed by the plant surface. Once inside the leaf, gaseous air pollutants diffuse into intercellular spaces and may be absorbed by water films to form acids or react with inner leaf surfaces. Though some particles can be absorbed into the tree, most particles settle on the branches, leaves and twigs of plants and are washed out by the rain. Throughout the world, different advanced technologies such as smog-free towers in the Netherlands and adhesive roads for particulate matter in London have been applied. However, these technologies are extremely costly and unaffordable for countries like India and therefore the most eco-friendly and cost-effective way is plantation of tolerant tree species alongside highways, city streets, in parks, and in residential yards"--

This book brings together the methods, models and formulae used for estimating air pollution concentrations in urban areas. From the ForewordThe visible effects of pollution in most cities in the developed countries have been reduced dramatically in the past thirty years. This has been achieved to a large extent by the replacement of most of the low-level sources, which burnt raw coal, by more modern appliances using gas, electricity or low-sulphur oil. The killer smog of 1952 could not be repeated unless there were to be a massive return to old-fashioned heating methods, due, for example, to excessive environmental constraints being applied to the more modern energy sources. It is important, therefore, to judge the impact of a new source in terms of its effect on the pattern of existing sources. One should also consider the environmental consequences of rejecting the new installation and examine the alternatives--that its product may either be denied to the community at large, produced elsewhere or produced using existing facilities. These facilities are probably less efficient and may therefore produce more pollution per unit of product than the new plant would. An objective, quantitative, urban-air-pollution model is clearly an essential component in such a decision-making process. Dr. Benarie has produced a distillation of existing modelling techniques which will, I hope, become the launching pad for many future models. As each city is unique, it will need its own tailor-made model, drawing on the best and the most appropriate techniques developed previously. Agreement with observations is the only real test of validity, because the physics and chemistry are so complicated that theoretical arguments are reduced to the role of assisting in the best formulation of the problem. Numerical precision must always rely on measurement. This is the approach that Dr. Benarie has adopted.--David J. Moore, Central Electricity Research Laboratires, Leatherhead, Surrey, UK.

Technology and Environment is one of a series of publications designed to bring national attention to issues of the greatest importance in engineering and technology during the 25th year of the National Academy of Engineering. A "paradox of technology" is that it can be both the source of environmental damage and our best hope for repairing such damage today and avoiding it in the future. Technology and Environment addresses this paradox and the blind spot it creates in our understanding of environmental crises. The book considers the proximate causes of environmental damageâ€"machines, factories, cities, and so onâ€"in a larger societal context, from which the will to devise and implement solutions must arise. It helps explain the depth and difficulty of such issues as global warming and hazardous wastes but also demonstrates the potential of technological innovation to have a constructive impact on the planet. With a range of data and examples, the authors cover such topics as the "industrial metabolism" of production and consumption, the environmental consequences of the information era, and design of environmentally compatible technologies.

Traffic-Related Air Pollution synthesizes and maps TRAP and its impact on human health at the individual and population level. The book analyzes mitigating standards and regulations with a focus on cities. It provides the methods and tools for assessing and quantifying the associated road traffic emissions, air pollution, exposure and population-based health impacts, while also illuminating the mechanisms underlying health impacts through clinical and toxicological research. Real-world implications are set alongside policy options, emerging technologies and best practices. Finally, the book recommends ways to influence discourse and policy to better account for the health impacts of TRAP and its societal costs. - Overviews existing and emerging tools to assess TRAP's public health impacts - Examines TRAP's health effects at the population level - Explores the latest technologies and policies--alongside their potential effectiveness and adverse consequences--for mitigating TRAP - Guides on how methods and tools can leverage teaching, practice and policymaking to ameliorate TRAP and its effects

Anthropogenic sources of air pollution / Chinmay Mallik, Max Planck -- Biogenic sources of air pollution: / Harpreet Kaur and Ruchi Kumari -- Transport of air pollutants / Naveen Chandra and Vineet Goswami -- Methods for measurement of air pollutants / S. Tiwari and N. Mishra -- Air pollution modelling apects, an overview / Monojit Chakraborty, Sangeeta Bansal, Renu Masiwal, Amit Awasthi -- Indices used for assessment of air quality / Prashant Rajput, Gyanesh Kumar Singh and Tarun Gupta -- Impact of air pollution on the environment and economy / Saurabh Sonwani and Vandana Maurya -- Effects of air pollution on human health / Priyanka Kulshrestha -- Air pollution in mega cities / Arti Choudhary, Manisha Gaur and Anuradha Shukla -- Cost effective technologies used to curb air pollution / Ravi Singh1and Saumya Singh -- Chemical and isotopic characterization of atmospheric contaminants / Vineet Goswami and Naveen Chandra -- Air pollution control by policies and laws / Ruchi Singh and Amit Kumar

This book analyses the technical and social systems that satisfy these needs and asks how methods can be put into practice to achieve this.

New edition of introductory textbook, ideal for students taking a course on air pollution and global warming, whatever their background. Comprehensive introduction to the history and science of the major air pollution and climate problems facing the world today, as well as energy and policy solutions to those problems.