Urban people change their environment through their consumption of food, energy, water, and land. And in turn, the polluted urban environment affects the health and quality of life of the urban population.
People who live in urban areas have very different consumption patterns than residents in rural areas. In China during the s, the urban populations consumed more than twice as much pork as the rural populations who were raising the pigs. But even a decade later, urban populations had 60 percent more pork in their diets than rural populations.
The increasing consumption of meat is a sign of growing affluence in Beijing; in India where many urban residents are vegetarians, greater prosperity is seen in higher consumption of milk.
Urban populations not only consume more food, but they also consume more durable goods. In the early s, Chinese households in urban areas were two times more likely to have a TV, eight times more likely to have a washing machine, and 25 times more likely to have a refrigerator than rural households. Energy consumption for electricity, transportation, cooking, and heating is much higher in urban areas than in rural villages. For example, urban populations have many more cars than rural populations per capita.
Almost all of the cars in the world in the s were in the United States. Today we have a car for every two people in the United States. If that became the norm, in there would be 5.
In China the per capita consumption of coal in towns and cities is over three times the consumption in rural areas. Economies, therefore, often become more efficient as they develop because of advances in technology and changes in consumption behavior.
And the increased consumption of energy is likely to have deleterious environmental effects. Urban consumption of energy helps create heat islands that can change local weather patterns and weather downwind from the heat islands. The heat island phenomenon is created because cities radiate heat back into the atmosphere at a rate 15 percent to 30 percent less than rural areas.
The combination of the increased energy consumption and difference in albedo radiation means that cities are warmer than rural areas 0. Cloudiness and fog occur with greater frequency. Precipitation is 5 percent to 10 percent higher in cities; thunderstorms and hailstorms are much more frequent, but snow days in cities are less common.
Urbanization also affects the broader regional environments. Regions downwind from large industrial complexes also see increases in the amount of precipitation, air pollution, and the number of days with thunderstorms. Urban areas generally generate more rain, but they reduce the infiltration of water and lower the water tables. This means that runoff occurs more rapidly with greater peak flows. Flood volumes increase, as do floods and water pollution downstream.
Many of the effects of urban areas on the environment are not necessarily linear. Bigger urban areas do not always create more environmental problems. And small urban areas can cause large problems. Much of what determines the extent of the environmental impacts is how the urban populations behave — their consumption and living patterns — not just how large they are. The urban environment is an important factor in determining the quality of life in urban areas and the impact of the urban area on the broader environment.
Some urban environmental problems include inadequate water and sanitation, lack of rubbish disposal, and industrial pollution. The health implications of these environmental problems include respiratory infections and other infectious and parasitic diseases. Obesity: preventing and managing the global epidemic: World Health Organization; Accessed 4 Aug Nour NN.
Obesity in resource-poor nations. Reviews in obstetrics and gynecology. Tomkins A, Watson F. Malnutrition and infection: a review. Nutrition Policy Discussion Paper. Schaible UE, Stefan H. Malnutrition and infection: complex mechanisms and global impacts. PLoS medicine. Dietary pattern, nutrient intake and growth of adolescent school girls in urban Bangladesh. Public health nutrition. Obesity and Overweight.
World Health Organization, Geneva Fact sheet no ; Why is the developed world obese? Annual review of public health. The impact of activity based working ABW on workplace activity, eating behaviours, productivity, and satisfaction.
International journal of environmental research and public health. Urban—rural disparities in energy intake and contribution of fat and animal source foods in Chinese children aged 4—17 years. Geveva: World Health Organization; Australian Institute of Health and Welfare.
Risk factors to health. World Health Organization releases country estimates on air pollution exposure and health impact. Geneva: World Health Organization; Megacities sustainable development and waste management in the 21st century. World Congress; Rapid urbanization and mega cities: The need for spatial information management.
Research study by FIG commission. Road traffic related mortality in Vietnam: evidence for policy from a national sample mortality surveillance system. BMC public health. Abebe T. Young people: Participation and sustainable development in an urbanizing world: Un-Habitat; Download references. You can also search for this author in PubMed Google Scholar. MAK planned the study, analyzed, and prepared the manuscript.
ET and EM helped in the preparation of the manuscript. All authors read and approved the final manuscript. Correspondence to Md Abdul Kuddus. Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Reprints and Permissions. Kuddus, M. Urbanization: a problem for the rich and the poor?. Public Health Rev 41, 1 Download citation. The increased concentration of people, physical assets, infrastructure and economic activities mean that the risks materializing at the city level will have far greater potential to disrupt society than ever before.
Urbanization is by no means bad per se. It brings important benefits for economic, cultural and societal development. Well managed cities are both efficient and effective, enabling economies of scale and network effects while reducing the impact on climate of transportation. As such, an urban model can make economic activity more environmentally-friendly.
Further, the proximity and diversity of people can spark innovation and create employment as exchanging ideas breeds new ideas. But these utopian concepts are threatened by some of the factors driving rapid urbanization. For example, one of the main factors is rural-urban migration, driven by the prospect of greater employment opportunities and the hope of a better life in cities. But rapidly increasing population density can create severe problems, especially if planning efforts are not sufficient to cope with the influx of new inhabitants.
The result may, in extreme cases, be widespread poverty. The Global Risks Report looks at four areas that face particularly daunting challenges in the face of rapid and unplanned urbanization: infrastructure, health, climate change, and social instability. In each of these areas we find new risks that can best be managed or, in some cases, transferred through the mechanism of insurance.
The availability and quality of infrastructure are at the core of many of the challenges faced by rapidly urbanizing cities in developing countries, while underinvestment is posing similar challenges in most developed economies WEF data.
Infrastructure failure would have significant implications for property and business continuity for city authorities as well as local and central Government bodies. Insurers can help in these areas in terms of risk engineering advice on infrastructure maintenance and also appropriate levels of insurance property damage and business interruption coverage. As cities expand rapidly, there is a risk that infrastructure will not keep pace with their growth or the increased expectations of their populations.
Action is urgently needed to close the infrastructure gap and reduce the potential for risks to have catastrophic cascading effects. The OECD estimates that governments will have to spend approximately USD 71 trillion by to provide adequate global infrastructure for electricity, road and rail transport, telecommunications, and water. This level of financing may not be achievable given that many governments are under tight budget constraints and that many developing countries allocate much of their national income to meeting the basic needs of their population.
Consequently, cities are looking for public-private collaboration to involve the private sector in the design, construction and maintenance of infrastructure. Throughout the 20 th century, the health of city dwellers increasingly benefited from better access to education and healthcare, better living conditions, and targeted public-health interventions. In advanced economics, emergency medical care can be accessed within hours and advanced facilities for longer term treatments are readily accessible.
However, when urbanization is rapid and unplanned, a combination of high population density, poverty and lack of infrastructure can have the opposite effect, fostering conditions for communicable diseases to flourish.
It is striking that, today, almost million urban dwellers lack adequate sanitation. The problem is particularly acute in sub-Saharan Africa and south-central Asia, where 62 percent and 43 percent, respectively, of the urban population live in slums and are faced with unacceptable levels of risk to illnesses, worm infections, cholera and diarrhea.
0コメント