Pollution due to urbanisation

Human beings have become an increasingly powerful environmental force over the last 10,000 years. With the advent of agriculture 8,000 years ago, we began to change the land. And with the industrial revolution, we began to affect our atmosphere. The recent increase in the world’s population has magnified the effects of our agricultural and economic activities. But the growth in world population has masked what may be an even more important human-environmental interaction: While the world’s population is doubling, the world’s urban population is tripling. Within the next few years, more than half the world’s population will be living in urban areas.

The level and growth of urbanization differ considerably by region . Among developing countries, Latin American countries have the highest proportion of their population living in urban areas. But East and South Asia are likely to have the fastest growth rates in the next 30 years. Almost all of future world population growth will be in towns and cities. Both the increase in and the redistribution of the earth’s population are likely to affect the natural systems of the earth and the interactions between the urban environments and ural populations desire for the advantages that urban areas offer. Urban advantages include greater opportunities to receive education, health care, and services such as entertainment. The urban poor have less opportunity for education than the urban nonpoor, but still they have more chance than rural populations.

Urban fertility rates, though lower than rural fertility rates in every region of the world, contribute to the growth of urban areas. Within urban areas, women who migrated from rural areas have more children than those born in urban areas. Of course, the rural migrants to urban areas are not a random selection of the rural population; they are more likely to have wanted fewer children even if they had stayed in the countryside. So the difference between the fertility of urban migrants and rural women probably exaggerates the impact of urban migration on fertility.

ENVIRONMENTAL EFFECTS OF URBANIZATION

Urban populations interact with their environment. 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. For example, urban populations consume much more food, energy, and durable goods than rural populations. In China during the 1970s, the urban populations consumed more than twice as much pork as the rural populations who were raising the pigs.With economic development, the difference in consumption declined as the rural populations ate better diets. 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 1990s, 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. This increased consumption is a function of urban labor markets, wages, and household structure.

HEALTH EFFECTS OF ENVIRONMENTAL DEGRADATION

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.Unfortunately, reducing the problems and ameliorating their effects on the urban population are expensive.

The health implications of these environmental problems include respiratory infections and other infectious and parasitic diseases. Capital costs for building improved environmental infrastructure — for example, investments in a cleaner public transportation system such as a subway — and for building more hospitals and clinics are higher in cities, where wages exceed those paid in rural areas. And urban land prices are much higher because of the competition for space. But not all urban areas have the same kinds of environmental conditions or health problems. Some research suggests that indicators of health problems, such as rates of infant mortality, are higher in cities that are growing rapidly than in those where growth is slower.