World Resources 1996-97
(A joint publication by The World Resource Institute, The United
 Nations Environment Programme, The United Nations Development
 Programme, and the World Bank)
(Data edited by Dr. Róbinson Rojas)

2. Urban Environment and Human Health

INTRODUCTION

Urbanization is one of the major social changes sweeping the globe, especially in developing countries, where urban growth rates are the most intense. Soon, a majority of the world's people will be living in urban environments quite unlike the rural settings that have been home to most of human society to date. Urbanization brings fundamental changes in the ways people live--in the number of people they see, in the places they work, and often in the quality of the water they drink, the air they breathe, and the housing in which they live.

Such changes have profound implications--both positive and negative--for the health of city residents. On the one hand, urbanization and economic development have brought dramatic improvements in health, largely because of environmental improvements and, in part, increased access to health services. Health statistics show that in the more highly urbanized countries, people tend to have the longest life expectancies and children under age 5 tend to have the lowest rates of mortality (1). Even within countries, urban-rural comparisons of indicators such as infant mortality and vaccination coverage show that there are significant advantages in urban areas. (See Table 2.1.)

However, urbanization can also have many negative influences on human health. For much of the world, growth in urban populations is synonymous with growth in urban poverty, both in absolute and in relative terms (2). Increasingly, cities are becoming the world's starkest symbol of the maldistribution of resources, both physical and societal. These inequalities have serious impacts on the health of urban dwellers everywhere, but especially in the fast-growing towns and cities in the developing world.

This chapter examines these negative impacts of urbanization and the urban environment on human health, particularly in the developing world. Indisputable evidence ties ill health to deficiencies in the physical environment, including inadequate water and sanitation, flimsy, overcrowded housing, air pollution, uncollected garbage, and dangerous workplaces. In poor cities of the developing world, infectious and parasitic diseases related to these deficiencies continue to exact an enormous toll on human health.

Now there is increasing evidence of the role of social factors-- including alienation, high rates of unemployment, ethnic tensions, and urban poverty--in influencing health as well. The effects of the urban social environment are by no means independent of physical conditions; they are interrelated. The political and economic structures within a city fundamentally determine the distribution of and access to the physical, biological, and social benefits that cities provide. In other words, the poorest groups within a city face the greatest exposure to physical and biological threats and have the least access to protective services.

These social factors affect health indirectly, through changes in behavior. But the urban social environment also contains direct health threats, such as urban violence, drug abuse, and depression and other psychosocial illnesses. These problems are of increasing importance in cities across the globe. Indeed, throughout the developed world, physical threats have largely receded and social factors are emerging as the greatest threats to public health.

For these reasons, the term environment is defined here to include not just the physical elements associated with the built environment but social factors as well. (See Box 2.1.)This chapter examines, in particular, evidence linking socioeconomic inequities in cities with inequities in health. First, the chapter describes how health problems stemming from the urban environment vary dramatically from city to city, depending in large part on a city's developmental status or wealth. Next, it examines the dramatic differences between rich and poor within the same city. The chapter then explores in greater detail how elements of both the physical environment and the social environment interact to increase the burden of ill health.

Attention to the social factors that affect the health of urban dwellers is relatively new. Past analyses have tended to focus on elements of the physical environment, usually in isolation. If policies to improve health are to succeed, they must recognize the interconnections between physical and societal factors and strive for an integrated approach. In short, simply providing better physical facilities such as improved sanitation and water supply-- although essential--is not enough to address the serious health problems that plague urban residents.

Topics Covered in Chapter 2

•Health Profiles of Urban Dwellers
•The Urban Physical Environment and Health
•The Urban Social Environment and Health
•Multisectoral Strategies for Improving the Health of Urban Dwellers

Boxes

•Can We Improve Neighborhood Quality in Neglected U.S. Cities?
•ASHA Works to Improve Health in Delhi
•The Black Death Revisited: India's 1994 Plague Epidemic
•Household Environmental Problems, Wealth, and City Size
•Community Perceptions of Urban Health Risks


References and Notes 


Table of Contents
Next Section