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Impact of Urbanization on Human Health

Urbanization or Urban Drift is the physical growth of urban areas as a result of global change. Urbanization refers to a process in which an increasing proportion of an entire population lives in cities and the suburbs of cities. Urbanization is also defined by the United Nations as movement of people from rural to urban areas with population growth equating to urban migration.
Natural population increase (high births than death) and migration are noteworthy factors in the growth of cities in the developing countries. It is possible because of improved medical care, better sanitation and improved food supplies, which reduce death rates and cause populations to grow.

The data of urban development in the late 20th century surpass any other demographic indicators.
 The proportion of the world’s population that lives in cities rose from 29 per cent in 1950 to 47 per cent in 1998, and 55 per cent is anticipated by 2015. According to latest predictions 60% of the world’s population are expected to be urban dwellers by 2030 (Table 1). Although two thirds of urban residents live in cities of less than a million people, data show the increment in the number of megacities (population with more than 10 million). In 1975 there were five, by 1995 there were 15 and by 2015 there are expected to be 26 megacities.
 By 2015, according to UN Population Fund (UNFPA), there will be three megacities in Southeast Asia-Jakarta (17.3 million), Metro Manila (14.8 million) and Bangkok (10.1 million). The expansion of urban areas in such a way exerts a remarkable amount of stress on the environment.

Table 1. Global proportion of the urban population increase (Source: UN Population Division)
Year                  Urban population (million)             Proportion
1900                            220                                       13%
1950                            732                                       29%
2005                           3,200                                     49%
2030                          4,900                                     60%
The situation of Slum
There are 828 million slum dwellers in the world and according to UN; one of every three of the world’s city residents lives in inadequate housing with few or no basic services. The world’s slum population is expected to reach 1.4 billion by 2020. The slums have no durable housing and are overcrowded, insufficient access to fresh water, poor sanitation which ultimately affects the health status of the dwellers. It is widely assumed that cities are far better places than rural areas for accessing safe and convenient water and sanitation services, but in developing countries, access to urban services often differs widely between the rich and the poor. On average, urban dwellers have higher incomes and live healthier, easier lives than their rural counterparts. Urban children under two have a 25 per cent better chance of survival to adulthood than rural children. While on the whole urban populations have greater access to clean drinking water and sanitation than their rural counterparts, between a quarter and a half of urban inhabitants in developing countries live in slums. In Karachi (Pakistan), a city of 10 million people, 40 per cent of the population lives in squatter colonies and one in five babies do not reach their first birthday.

Climate Change
The most important threat of rapid urbanisation may be global climate change. World greenhouse gas emissions, one of the major factors responsible for climate change, have increased 70% between 1970 and 2004. Much of the increase is due to growth in the sectors of energy (+145%), transportation (+120%) and industry (+65%) and to the reduction of forest land and land use changes (40%). The USA is the biggest emitter of greenhouse gases worldwide. US emissions increased to 7 billion tones of CO2 in 2004, 16% higher than emissions in the late 90's. The 20 largest cities consume 80% of the world’s energy and urban areas generate 80% of greenhouse gas emissions worldwide. Combustion engines are one of the important contributors for greenhouse gas accumulation in the atmosphere and are responsible for climate changes.
In rural areas, a large part of the incoming solar energy is used to evaporate water from vegetation and soil. In cities, where less vegetation and exposed soil exists, the majority of the sun’s energy is absorbed by urban structures and asphalt. Hence, during warm daylight hours, less evaporative cooling in cities allows surface temperatures to rise higher than in rural areas. Additional to this, the city heat is given off by vehicles and factories, as well as by industrial and domestic heating and cooling units. This effect causes the city to become 2 to 10o F (1 to 6o C) warmer than surrounding landscapes. Impacts also include reducing soil moisture and intensification of carbon dioxide emissions. Environmental degradation, climate change, natural disasters threaten the liveability of cities. Cities are highly vulnerable to rising sea levels and severe weather associated with climate change. In a vicious circle, climate change will increase energy demand for air conditioning in urban areas and contribute to the urban heat island effect through heat pollution. Heat pollution, smog and ground-level ozone are not just urban phenomena; they also affect surrounding rural areas, reducing agricultural yields, increasing health risks and spawning cyclones and thunderstorms.

Human health in urban areas may suffer as a result of climate change, especially in poor urban areas whose inhabitants are least able to adapt. Poor areas that lack health and other services, combined with crowded living conditions, poor water supply and inadequate sanitation, are ideal for spreading respiratory and intestinal diseases, and for breeding mosquitoes and other vectors of tropical diseases such as malaria, dengue and yellow fever. Changes in temperature and precipitation can spread disease in previously unaffected areas and encourage it in areas already affected. Changes in climate and the water cycle could affect water supply, water distribution and water quality in urban areas, with important consequences for water-borne diseases.

It is estimated that as many as 60 per cent of all urban dwellers will be under the age of 18 by 2030. Adolescence is the time when most young people initiate sexual activity. Lack of access to sexual and reproductive health information and services can lead to unwanted pregnancies and to unsafe abortions. Young unmarried women faced with uncertain financial futures may opt for early marriage or involvement in prostitution to obtain bread for themselves and their children, increasing their risk of sexual violence and exposure to HIV/AIDS. About half of all new HIV infections occur among young people aged 15-24, in particular among girls. The increase in access to capital and microenterprise support can help young people fulfil their economic potential and HIV/AIDS can be chaecked.

The case of Women
For urbanisation to be sustainable, policy makers and governments should be aware of the gender impacts of rapid urbanization, slum growth, rural-urban movement. There should be no gender discrimination and better promotions of equal opportunities. Women and girls often suffer the worst effects in the society. They have responsibility for almost everything in the family and this reduces time for education, employment, childcare and rest. A lack of separate-sex toilet facilities in schools can cause girls to miss classes or drop out of school along with severe health disorders. According to the World Bank’s economic research, poverty incidence tends to be lower in countries with more gender equality, while economic growth also appears to be positively correlated with gender equality.

Almost one fifth of married women in developing countries have an unmet need for family planning services. High levels of unmet need for effective contraception have led to 70 to 80 million uninten¬ded pregnancies each year in developing countries. From a demographic standpoint, urbanization accelerates the decline of fertility by facilitating the exercise of reproductive health rights. In urban areas, new social aspirations, the empowerment of women, changes in gender relations, the improvement of social conditions, higher-quality reproductive health services and better access to them, all favour rapid fertility reduction. This may be one of the benefits of the urbanization.

Access to healthcare is particularly critical for women, because of their reproductive functions, they are disproportionately burdened in the society. Better access to education and employment for women contributes to their overall empowerment, their capacity to exercise their right to health, including reproductive health, and, overall, improves their life chances.

In developing countries, maternal mortality remains astonishingly high, at about 529,000 a year, more than 99 per cent in developing countries. Four out of five deaths are the direct result of obstetric complications, most of which could be averted through delivery with a skilled birth attendant and access to emergency obstetric services. Maternal mortality is generally lower in urban areas due to skilled healthcare professionals during pregnancy. Poor urban women are less likely to deliver with a skilled birth attendant. For example, only 10-20 per cent of women deliver with skilled health personnel in the slums of Kenya, Mali, Rwanda and Uganda, compared to between 68 and 86 per cent in non-slum urban areas. The reasons why poor urban women do not seek maternal care are poverty, involvement with other responsibilities, absence of supporting infrastructure such as transportation and childcare. In urban areas, inclusive health policies and programmes, accompanied by better targeting of services and resources, could rapidly improve women’s health, in particular their reproductive health. This is not possible for rural ladies. Poor urban women are exposed to higher levels of reproductive health risks than their urban counterparts. Rural women are also less likely to obtain good-quality pre and post pregnancy services. There is no access to reproductive health information and services for them. They are more likely to be subject to harmful traditional practices. In hilly regions of Nepal, the practice of Chhaupadi is terrible one. Poor women within cities are considerably less likely to use contraception and have higher fertility rates than their more prosperous counterparts.
In urban environment, the risk and prevalence of HIV/AIDS increases along with injection of drug. Sexually transmitted infections and tuberculosis, which increase the acquisition and transmission of HIV, are also more common in urban areas. Sex workers and poor women in urban areas are particularly vulnerable to HIV infection. They are more likely to become victims of sexual violence or human trafficking; increasing their risk and negotiation of safe sex is worthless many times. But now-a-days, HIV victims are decreasing because of better education and more exposure to people living with HIV/AIDS.

Urbanization Affects
Shelter scarcity increases mortality rates for children under five. In Ethiopia, the mortality rate in slums (180 per 1,000 live births) is almost double that in non-slum housing (95). Overcrowded housing and unhealthy environment, without adequate water and sanitation promote epidemics of diseases such as pneumonia, tuberculosis, diarrhoea and other communicable diseases or those associated with air pollution. The death toll from lung disease associated with urban air pollution could be half a million a year in China alone. The notorious traffic congestion in Bangkok costs an estimated 2 per cent of Thailand’s GDP. The wide range of effects includes degradation of the environment (soil erosion, deforestation), destruction of watersheds and wetlands, traffic congestion. Most cities in the developing world discharge their sewage untreated into rivers, The rivers are also polluted with pesticide contamination from urban agriculture, and manufacturing industries, wastewater from urban drains and municipal dumping of waste. River pollution is particularly found to be worse where rivers pass through cities and the most widespread is contamination from human excreta, sewage and oxygen loss. Today much of the agricultural land has been converted into residential centres. The fertile land of Kathmandu valley is now concrete-hub, causing the loss of livelihoods based on agricultural and animal breeding. The conversion of farm lands and watersheds for residential purposes have negative consequences on food security, water supply as well as the health of the people, both in the cities and in the peri-urban areas. Similarly, garbage management is also very poor in most of the cities such as Kathmandu valley, Janakpur Municipality.
The improper urbanization affects many ways-
– High urban densities, lack of green areas
– Informal development both within the city and in the periphery, for example slums
– Unsustainable land use
– Food, water and energy insecurity
– Lack of basic services such as public transportation, fresh water, parking areas, waste management, sanitation and public toilets along with traffic congestion etc.
– Crime, increase of social and economic inequalities
– Water, soil and air pollution; environmental degradation
– Climate change
The association between psychotic disorders and living in urban areas appears to be a reflection of increased social fragmentation present within cities, according to a report in the issue of Archives of General Psychiatry, (September, 2009), one of the Journal of American Medical Association.
Excessive noise in the cities is not only annoying and distracting, but can lead to hearing loss, high blood pressure, sleep disturbance and extreme stress. High and continuous noise levels disturb the natural cycles of animals and reduce their usable habitat. Construction dust, for example sand, is classified as PM10- particulate matter less than 10 micron in diameter, invisible to the naked eye, penetrate deeply into the lungs and cause a wide range of health problems including respiratory illness, asthma, bronchitis and even cancer. Diesel as well as petrol is also responsible for emissions of carbon monoxide, hydrocarbons, nitrogen oxides and carbon dioxide. The world’s forest areas are shrinking with air quality imbalance causing health problems in many ways.
The Issues to be addressed
Due to poor awareness towards different types of pollution, such as air, water, sanitation, has made people vulnerable to many diseases. Urban poor communities have been constrained by lack of possession, economic constraints, in obtaining affordable access to basic needs. In this context, the issues of whether services to the poor should be individualised and whether community services should be provided in non-notified slums should be addressed. Provision of individual toilets should be prioritised. Municipal wastewater and storm water drainage must be safely managed. Recycle and reuse of treated wastewater for non potable applications should be implemented wherever possible. Solid Waste collected and disposed off fully and safely.
Urban sprawl is making the nation's drought even more painful by diverting rainwater needed to recharge groundwater tables. The impervious surfaces that characterize sprawling development are sweeping increasing amounts of water into gutter. It is reducing groundwater tables. Much of the water that runs off paved surfaces is polluted, which eventually increases pollution in rivers, streams and coastal areas. The adequate awareness programmes on rainwater harvesting is essential now.
Preserving the rights of our children and grandchildren to health and happiness depends on what we do today about global environmental change: population growth, pollution, resource degradation and waste generation. It is clear that sustainable development cannot be achieved without sustainable urbanisation. There should be appropriate plan for a healthy city. The municipal authorities need to address the consequences of population growth. Without proper planning of the settlement of the population explosion, there will be stress to existing arrangement and services. The inevitability of further population growth should be considered while designing a city. Population trends, urbanization and environmental challenges require broad and long-term policy responses because policies cannot change the past, but they can shape the future by providing direction toward a better set-up. The distribution of economic opportunities to rural areas will halt the entry of rural people to urban areas. In addition to this, development planning and process should not be heavily concentrated on urban areas. With population and urbanization being checked, global challenges such as climate change, poverty and food insecurity can be tackled effectively. In the areas of the environment and health, problems of emission reduction, supply of clean drinking water, sewage and rubbish disposal, food security and poverty reduction are the most important.
Personal vehicle use has to be considered a privilege, not a right. No solution is better than fewer vehicles and reduced vehicle use to control traffic congestion and air pollution. Electric vehicles are desirable instead of vehicles that emit hydrocarbons. Government can encourage the reduction of vehicular use by:
•Increase Public transportation
•Separate commercial and private traffic to increase efficient use of roads
•Building more walking paths, bicycle routes and roads for small electric vehicles with grants and tax incentives for all non-polluting transportation alternatives
•Redefine road use by defining access privileges - no longer a right
•Road toll and increased gasoline and vehicle registration taxes
Human activities and consumption patterns are responsible for environment destruction and causing adverse impacts on the quality of natural resources such as water, forest, food and ultimately the human health. The current condition of the environment is barely sustainable enough to maintain a decent human existence. As a result, the environment, particularly human health, is under constant threat. We have to act now because BETTER LATE THAN NEVER!

Selected References:
 Urban Migration and Urbanization in Nepal, Indra P. Tiwari, Asia-Pacific Population Journal, April 2008
 (2010 September 08)
 Our cities, our health, our future, Report of the WHO Commission for health equity in urban settings, WHO
 Urbanization and sustainability in Asia, BRIAN ROBERTS and TREVOR KANALEY, 2009
 (2010 September 08)


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