Urbanization

The movement of population from rural to urban areas and the resulting increase in proportion of a population that resides in urban areas.

In the last two decades, the urban population of the developing world has grown by an average of 3 million people per week. By the middle of the 21st century, the total urban populations of the developing world will more than double, increasing from 2.3 billion in 2005 to 5.3 billion in 2050. By 2050, Asia will host 63 per cent of the global urban population, or 3.3 billion people; Africa will have an urban population of 1.2 billion, or nearly a quarter of the world’s urban population.

Altogether, 95 per cent of the world’s urban population growth over the next four decades will be absorbed by cities in developing countries. (State of the World’s Cities 2008/2009, UN-HABITAT). In India, it is expected that 41% of the population will be living in cities by 2030, as against the current 28%. Nearly 80 million of the urban population are poor.

Cityscapes present health challenges

Urbanization must consider the issues related to the daily existence of such a vast number of people such as provision of basic services (housing, clean drinking water and sanitation), migration, urban economy and livelihoods, microfinance for urban poor, education and health, unorganized sector and livelihoods.

Low-income groups (especially migrants in search of a living) are often most vulnerable to environmental health risks associated with poor health quality, lack of safe water and poor sanitation. They may also face a dual environmental and ecological burden - they live in unsafe environments - close to polluting industries or garbage dumps; because they lack toilets, open defecation is common - leading to a cycle of pollution, contamination and diseases and overall poor living conditions. Urbanization is also associated with an increase in diseases such as diabetes and hypertension due to changing lifestyles, alteration in food consumption patterns and decrease in physical activity.

In addition, urbanization brings with it the boom in consumption indicated by increase in the number of cars, rapid growth of housing (the urban sprawl), growth of slums and shanty colonies — all of which exert pressure on infrastructure and environment by:

Depleting natural resources: there is depletion of forest cover for purposes of building houses, building roads etc.; depletion of ground water resources
Increasing air pollution: emissions from industries, car exhausts, burning of fuels for household purposes
Increasing water pollution: increase discharge of industrial and human wastes damages aquatic ecosystems and causes deterioration of water quality;
Causing environmental degradation: damage to ecosystems; erosion of fertile top soil of agricultural land.

Unseen challenges

Urbanization and economic growth go hand in hand; ironically however, rapid urbanization is also associated with an increase in the growth of unplanned communities (slums) thus presenting a challenge for providing a sustainable environment(inclusive, productive, efficient and manageable) without impeding economic growth. Urbanization is necessary, no doubt but urban planning and foresight can minimize the damage to environment; this requires formulation and enforcement of relevant policies.

Indoor air pollution is a health threat for those who burn solid (i.e. biomass fuels and coal) especially in urban slums. The incomplete combustion of solid fuels releases pollutants such as Particulate Matter (PM), carbon monoxide, sulphur dioxide, nitrogen dioxide and other organic compounds into the atmosphere resulting in respiratory illnesses - especially in children.
Unfortunately, those who burn such fuels do not have the economic capacity to shift to the more expensive fuels - Liquid Petroleum Gas (LPG) which is less polluting.
Solid waste management is another urbanization challenge. Throwing garbage, defecating on roadsides and near railway tracks is a common sight and the stink of huge garbage dumps, proliferation of rodents, flies and mosquitoes - that carry various diseases - are a common sight in urban areas. So are sights of young boys and women scavenging through the garbage heaps - looking for refuse that they can re-cycle. Poor solid waste management can lead to a range of excreta and vector-related diseases.
Poor drainage leads to leptospirosis (a disease that is spread through rodent urine and poor drainage in construction). Improper drainage and solid waste can clog storm drains causing flooding and stagnant water provide feeding and breeding grounds for mosquitoes. Collectively, these can cause diarrhoea.
overcrowding, noise and air pollution and lack of green spaces are increasing stress levels in cities with the perception that it is a 'jungle out there'
Contamination of food, water and air and lack of basic amenities are threats that most cities have to deal with.

Help plan your city

You can work towards creating an institutional framework for a sustainable environment when you believe that your community is responsible for its own well being.

Partnerships between communities, local administrative bodies and NGOs can be critical for building healthy environments conducive to personal, social, and community health.
The need for sanitation may be met by community toilets where provision of individual toilets is not feasible for e.g. due to maintenance issues and/or limited sewerage networks for disposal.
The need for public transport should be demand driven taking into consideration geographical conditions.