How does pollution in large cities affect human health.doc

此文档收集于网络，如有侵权，请联系网站删除How does pollution in large cities affect human health (Q1)With the economic growth and the globalization in the world, the pollution of the environment has become more severe. Currently, environmental pollution is a widespread issue, which affects millions of people in the world. Pollution can be defined as harmful or poisonous substances which are introduced into the environment. Pollution has various kinds and the main pollutions in the large cities are water pollution, air pollution, solid waste pollution and metal pollution. According to Schell and Denham (2003), the effects of pollution on human health are different in urban and rural areas. Some urban features are still highly harmful to the human health. This essay will examine each of the pollution mentioned above and focus on the effects those pollutions given on human health in large cities.Water pollution can increase the possibility that people get some diseases like cancer. According to Rubin (n. d.), the causes of water pollution can be classified as direct and indirect. Due to the rapid industrialization and urbanization, the rates of liver and stomach cancer in cities increase (Wu, Maurer, Wang, et.al, 1999).For example, one of Chinas river, Huai River，has been polluted for about 8 years. Along some periods of the Huai River, people who have lived there for 3 or more years have a higher rate of cancer and birth defects than the normal people. In Fuyang, a large city along Huai River, 60 percent of people died from the exposure to the contaminated wastewater (Economy, 2004). Similarly, in developed countries, such as the U.S, a study by an Environmental Protection Agency which researched on 339 counties in the U.S with the polluted drinking water indicated that people in these areas have a higher risk of breast, bladder and stomach cancer (Davis and Webster, 2002). In conclusion, water pollution has a large damage on human health, which can leads to the various kinds of cancer. Urban air pollution is caused by many factors and may lead to some respiratory problems on people. For instance, industry pollution produces exhaust gases such as sulfur dioxide（SO2）, nitrogen dioxide（NO2）, nitric oxide（NO）; Traffic-related pollutants such as NO2 and ozone are also existed in the urban area. In China, it is indicated that 25% of deaths are caused by lung disease partly because of the serious urban air pollution (Seitz, 2008). Another example is that a study done by Environ Health Perspect on air pollution and health in Taiwan, gives the statistics that in the urban areas, the exposure to a mixture of air pollutants, such as SO2, NO2, and NO, which were mentioned above, has a strong association with the respiratory health in primary school students (Chen, Lai, Wang, et.al., 1998). Analogously, the urban traffic is also a main source of the air pollution. It is estimated that traffic-related pollutants such as NO2 and ozone which were mentioned above have been linked to the lung development on children in cities (Saxon and Diaz-Sanchez, 2005). It has been proved that air pollution is caused by multiple factors and will have a respiratory effect on people.Solid waste pollutions influence on human health is a long-run process. It takes a long period of time to engender germ and spread the contagion after firstly pollutes the water and the soil, resulting in diarrhea and other relevant diseases. According to Srinivas (n. d.), solid waste pollution can be classified into four types: agriculture, mining, industry and municipal. Among the four kinds above, the solid waste of the industry seriously polluted the environment. According to Jenkins, Maguire and Morgan (2004), a study carried out by the U.S. Environmental Protection Agency indicated that health and safety risks linked to the civic solid waste landfills. Plastic bags are one of the disposable goods which are regarded as typical solid waste pollutions. On June 1st, 2008, Chinese government banned the use of plastic bags, which really benefit the citizens a lot. Before that, plastic bags can easily be found on beaches or in waterways. Because the plastic bags require more than a century to decompose, they will affect human health according to the process above (Block, B., 2009). Children can easily be affected by the metal pollution. According to Seitz (2008), lead pollution has become more serious after World War . According to the Special Projects Team, (n. d.), lead pollution in the old houses are mainly come from lead paint. In the past 30 years, added lead has been banned from paint because of the exposed to the lead dust. Young children are more likely to be affected than the adults by the lead pollution because they love moving around. It is said that if a child has an abnormal lead level, he or she will have learning and behavioral problems in low level (Seitz, 2008).To sum up, this essay has focused on how the pollution in large cities affects human health. Firstly, water pollution affects human health primarily through drinking water, in that process, some poisonous material get into human body which can lead to some diseases such as cancers. Next, the exhaust gas is the main source of the air pollution in the urban area, which is breathed by the people and affects their respiration. Then, solid waste pollutes the water and soil and engenders some germ and spread the contagion, which brings some diseases like diarrhea. Fourth, metal pollution affects human, especially childrens nerve center if children touch some lead materials. This issue is highly important because it raises questions about the effects pollution gives on human health. To overcome these pollutions, policies, medical condition and the awareness of people to protect the environment are needed. It is urgent to improve the environment condition if people want to live a healthy life. Words: 966Bibliography: Anon. (n. d.) Special Projects Team online Available at: .uk/home/environment/pollution/lead_pollution/lead_and_paint.htm Accessed 10 December 2009.Block, B (2009) World Watch Institute online Available at: /node/6167 Accessed 5 December 2009.Chen, P., Lai, Y., Wang, J., Yang, C., Hwang, J., Kuo. H., Huang, S., Chan, C. (1998) Adverse Effect of Air Pollution on Respiratory Health of Primary School Children in Taiwan Environ Health Perspect 106:pp331-335Davis, D. L., Webster, P. S. (2002) The Social Context of Science: Cancer and the Environment. Annals of the American Academy of Political and Social Science online vol.584 pp13-34 Available at: /stable/pdfplus/1049764.pdf Accessed 16 December 2009.Economy, E. C. (2005) The River Runs Black. London: Cornell University PressJenkins, R. R., Maguire, K. B., Morgan, C.L. (2004) Host Community Compensation and Municipal Solid Waste Landfills. Land Economics online vol.80 pp513-528 Available at: /stable/pdfplus/3655807.pdf Accessed 16 December 2009Rubin, K. (n. d.), Sources of Water pollution online Available at: /GG/ASK/waterpol3.html Accessed 27 December 2009Saxon, A., Diaz-Sanchez, D. (2005) Air pollution and al