URBANIZATION AND HUMAN HEALTH

URBANIZATION ANDHEALTHHaliza Abdul Rahman, PhdAssociate ProfessorEnvironmental and OccupationalHealth Programme, School of HealthSciences, USM

INTRODUCTION In the past, the emphasis ofenvironmental action has often beenon wilderness, wildlife, endangeredspecies and the impact of pollution onnatural landscapes outside cities. Now the focus of attenttion is to thecity environments. City dwellers are atthe center of some of the mostimportant environmental issues.

Urbanization is an inevitablephenomenon that accompaniesthe development of a country. Worldwide are becoming anincreasingly urbanized species. The rapid urbanization of theworld’s population over thetwentieth century is described inthe 2005 Revision of the UN WorldUrbanization Prospects report.

Urbanization is defined as the process ofhuman movement and centralizationtowards and into cities and urban areas,with the associated industrialization, urbansprawl and lifestyle that brings. Urbanization does not only involve themovement of people from rural to urbanareas but also comes about as a result ofnatural increases in the urban areas.

The global proportion of urbanpopulation rose dramatically from13% (220 million) in 1900, to 29%(732 million) in 1950, to 49% (3.2billion) in 2005. It is projected that62% of the population, 6.5 billionpeople will live in cities by 2025.

According to the UN State of the WorldPopulation 2007 report, the majorityof people worldwide will be living intowns or cities, for the first time inhistory; this is referred to as the arrivalof the "Urban Millennium" or the'tipping point'. In regard to future trends, it isestimated 93% of urban growth willoccur in developing nations, with 80%of urban growth occurring in Asia andAfrica. It is estimated that by 2015there will be 36 megacities (more than8 million residents), 23 of them inAsia.

According to a new report, humans are building the equivalent of a citythe size of Vancouver (shown above) every week.(Credit: iStockphoto/Dan Barnes)

With the growing humanpopulations, we can imagine twofutures. In one, cities are pleasing andliveable, use resources from outsidethe city in a sustainable way,minimize pollution of the countryand allow room for wilderness,agriculture and forestry.

In the other future, cities continueto be seen as environmentalnegatives and are allowed to decayfrom the inside. People flee them to grander andmore expansive suburbs thatoccupy much land, and the poorwho remain in the city live in anunhealthy and unpleasantenvironment.

Although such a city appears to itsinhabitants to grow stronger and moreindependent, it actually becomes morefragile. Ironically, without care for the city, itpollute even more than in the past. A city grows at the expense of surroundingcountryside, destroying surroundinglandscape on which it depends. A nearbyareas are ruined for agriculture and thetransportation network extends, the use,misuse and destruction of theenvironment increase.

THE CITY AS AN ENVIROMENT A city changes the landscape andbecause it does, it also changes therelationship between biological andphysical aspects of environment. A city creates an environment thatis different from surrounding areas.City change local climate; they arecommonly cloudier, warmer andrainier than surrounding areas.

In a city, everything is concentrated,including pollutants. City dwellers are exposed to morekinds of toxic chemicals in higherconcentrations and to more humanproduced noise, heat and particulatesthan are their rural neighbors. In general, life in a city is riskierbecause of higher concentrations ofpollutants and pollutant-relateddiseases.

For example, lives are shortened byan average of one to two years inthe most polluted cities in theUnited States. The city with greatest number ofearly deaths is Los Angeles, with anestimated 5, 973 early deaths peryear, followed by New York with4,024, Chicago with 3,479 andPhiladelphia with 2,590.

URBAN CHARACTERISTIC Urban area are characterised by their highdensity population, who are accomodated bythe development of extensive road networks,housing schemes, service and productionindustries and recreational facilities.

However, in low and middle income countries withrapid urbanisation, there are areas which largeincreases in population density, an uncontrolledincrease in pollution (air and water) and a lack ofbasic infrastructure (health care, water, sewerageand waste disposal). The increasing concentration of people in urbancenters has strained the capacity of mostgovernments to provide basic services. Illegalslums and settlements are common. The numberof people living in slums and shanty townsrepresent about one-third of the people living incities in developing countries.

In such areas, people are usually deprived ofaccess to the basic facilities of drinking waterand waste disposal. Resources are notadequate for removal or disposal of waste.Residents have little access to facilities whichmake for a reasonable quality of life andhuman development.

\ Thus they often suffer from greater exposure todust, unpleasant smells, chemicals and noisepollution, and the nature of dwelling makes themless able to withstand such hazards. There is direct link between people dwelling insuch conditions and cholera, viral hepatitis,typhoid fever, schistomiasis, diarrhea and parasiticdiseases that are carried by water or poorsanitation, overcrowding and poor diet.

These circumstances have meant a rise inthese areas of communicable diseases, knownas the ‘diseases of poverty’ including malaria,respiratory diseases, nutritional deficiency anddrug-related illness.

For example, in Zambia, the most urbanizedcountry in the African region, water-borne diseasessuch as cholera and dysentery are prevalent dueto lack of access to clean water and badsanitation. More than half of the Mozambican urbanpopulation lives in unsanitary and unhealthyconditions and the levels of urban unemploymentare extremely high. The unhealthy conditions areputting a huge strain on the country’s healthsystem.

They are also exposed to health risks of moderncities – traffic, pollution etc., and suffer theconsequences of social and psychologicalinstability as the traditional support structures ofrural areas steadily disappear. Writing in the "Anatolian Journal of Psychiatry" in2008, M. Tayfun Turan and Asli Besirli found thatthe social problems associated with urbansocieties, the traffic problems and the generalanxiety about the future contributed to an increasein mental health disorders.

URBANIZATION AND HEALTH Urbanity and health involves the connectionbetween urban life and the living conditionsaffecting human health. Urbanization affects human health in several ways,from dietary patterns to the physical environment(Table 1). The concentration of people in urbanareas, with a multitude of economic activityincluding industrial production and extensivetransportation, contributes to air pollution, whichis a major health hazard.

Figure 1 Health effects of environmental pollutionSource: http://en.wikipedia.org/wiki/Pollution

Although urbanization allows more accessibility tohealth services, it also creates health hazards. Inpoor parts of the cities, health problems includeinadequate water and sanitation, limited or nowaste disposal and poor air quality, as well ascrowded living conditions and general poverty. Urbanization affects human health in severalways, from dietary patterns to the physicalenvironment. The concentration of people in urbanareas, with a multitude of economic activityincluding industrial production and extensivetransportation, contributes to air pollution, whichis a major health hazard.

In such urban areas the air, land and water areoften contaminated, spreading disease. In cities inthe more affluent parts of the world, healthhazards resulting from urbanization are mainlyconnected to air pollution, as well as crime, trafficand lifestyle. Some problems connected to the urban physicalenvironment affect virtually everyone, particularlyair pollution. The burning of fossil fuels fromtransportation, industry and energy production isthe main culprit regarding outdoor urban airpollution. Another health hazard common in, butnot exclusive to, the cities is connected to lifestyleand consumption patterns, including dietarychanges and obesity.

CONCLUSION Cities offer the lure of betteremployment, education, health care,and culture; and they contributedisproportionately to nationaleconomies. However, rapid, unplanned andunsustainable patterns of urbandevelopment are making developingcities focal points for many emergingenvironment and health hazards.

To make cities healthy, we must, allthose who deal with aspects of theurban system that directly or indirectlyaffect health, involve themselves inurban health planning. Urban planning can promote healthybehavior and safety through investmentin active transport, designing areas topromote physical activity and passingregulatory control on pollution andsafety.

Improving urban living conditions in theareas of housing, water and sanitationwill go a long way to mitigate healthrisks. Building inclusive cities that areaccessible and age-friendly will benefitall urban residents. Such actions do notrequire additional funding, butcommitment to redirect resources topriority interventions, thereby achievinggreater efficiency.

Urbanization is an inevitable phenomenon that accompanies the development of a country. Worldwide are becoming an increasingly urbanized species. The rapid urbanization of the world’s population over the twentieth century is described in the 2005 Revision of the UN World Urbanization Prospects report.