Official websites use. Share sensitive information only on official, secure websites. This article is made available via the PMC Open Access Subset for unrestricted research re-use and secondary analysis in any form or by any means with acknowledgement of the original source. In , a major demographic line was crossed: for the first time in history, the majority of the world population lived in cities rather than in towns and countryside Fig.
This shift has been occurring over the past years, with the most rapid rate of urban growth occurring over in the latter half of the twentieth century. Urban centers in the more developed regions of the world i. Urban and rural populations of the world, β World Urbanization Prospects: The Revision. New York Reprinted with permission of the United Nations. According to the United Nations Population Division, the urban areas of the world are expected to absorb the entirety of the projected world population growth through China and India together are expected to account for approximately one-third of the increase in the world urban population in this timeframe [ 1 ] Fig.
Urbanization is the result of migration from rural to urban locales as well as the imbalance between death and fertility rates in urban and rural localesβthat is, the proportionally higher ratio of births vs. Additional assumptions regarding the implications of urbanization will be explicitly addressed throughout this chapter. The effect of urbanization on health trends, morbidity, and mortality are numerous. In more developed countries and industrialized centers, for example, violent crimes, drug abuse, and motor vehicle accidents are more common health problems than in rural areas.
Environmental pollutants in industrialized centers across the spectrum of more and less developed nations have a deleterious impact on health. Rapid growth of urban centers with poor urban planning and little capacity to meet the needs of a rapidly growing population often leads to the development of slums and shantytowns.
Sanitation and waste removal, safe drinking water, secure housing, and access to adequate nutrition are other important challenges of urbanization. This chapter focuses on the infectious diseases implications of urbanization, which interrelate with the other health concerns listed above. Along with war and famine, infectious diseases have been a leading cause of death and disability in developing societies for as long as history has been recorded.
