URBAN HEALTH

The health of those who live in the more densely populated areas of the world is of interest and concern for two reasons: (1) the large numbers of persons involved, and (2) the fact that the population density of an urban area changes the potential for both public health problems and public health solutions. The potential for problems includes increased exposure to large a number of individuals who can spread infectious conditions, larger volumes of waste products at risk of poor handling, the presence of pollutants, an apparent increase in stress, and a concentration of more serious mental health problems. Solutions are influenced by economies of scale in providing services, a more varied array of resources, and the potential for closer proximity to others with similar interests and needs. Opportunities to work with others who share a concern increases the likelihood of identifying appropriate actions and generating political support for solutions.

Over time, the population of the world has become much more urban. In 1900, 39.6 percent of the United States population was defined as "urban" by the Bureau of the Census; by 1990 the proportion considered urban was 75.2 percent. The definition of urban as used, however, does not include solely the densely populated centers such as Chicago or New York City. The Census Bureau considers any area with over 2,500 population to be urban; this is a "population center" many people are more likely to call a village or hamlet than a city. The definition more consistent with the common concept of an urban area includes communities of 100,000 or more, with a nucleus of at least 50,000 and surrounding communities that share a high degree of social and economic integration. By this definition, only the 276 major metropolitan areas of the United States are considered urban.

Social cohesion and social breakdown are the two ends of a spectrum describing the relationship people in a given setting experience. The greater the cohesion, the more likely the group is to work together, to share common values, and to find positive solutions to problems in ways that are inclusive of all members of the group. Conversely, when social breakdown has occurred, individuals are left to struggle with the challenges of living alone, people turn on one another in ways that are damaging, and problems accumulate to a level incompatible with a healthy life. Urban areas of today have within them neighborhoods that could be described as fully cohesive, but far too many urban areas are at, or are closer to, the other end of the spectrum.

AREAS OF CONCERN

The issue of urbanization is not just one of larger numbers of persons gathered into urban geopolitical units. The geographic size of a city makes a difference as well. For example, in central New York City (Manhattan), there are 52,419 people per square mile; in Cook County, Illinois (Chicago), 5,398; in Los Angeles County, California, 2,183; and in Dade County, Florida (Miami), 996.1. In contrast, the overall United States population density is 70.3 people per square mile; and in 1790 the nation had a population density of 4.5 people per square mile. The less concentrated population of today's sprawling urban areas present challenges of a different kind, such as the difficulties of organizing public transportation. Lack of mass transportation may mean increased pollution from individual use of internal combustion engines, and it may mean that individuals lacking a personal car may have difficulty reaching health services.

From an economic perspective, urban populations experience some of the extremes of income inequality, with large differences in income between the highest- and lowest-earning segments of the population. Income inequality has been increasing in the United States over the last twenty-five years, and, for the low-earning segment, can have a significant negative impact on health. Areas with high income inequality and a low average income have been reported as experiencing nearly 140 deaths per 100,000 people, compared with a rate of 64.7 per 100,000 in other areas. This impact is greater for infants and those between 15 and 64 years of age. A study of thirty large metropolitan areas revealed that when poverty is concentrated within a geographic area, mortality is significantly elevated. Conversely, a concentration of affluence is associated with lower mortality, at least in the elderly.

Urban populations in the United States include large ethnic and racial minority populations. The combination of segregation and discrimination felt by minority groups in urban areas can also have an impact on health, whether due to limitations in access to health services, education, and jobs; or the increase in stress due to the tensions of being a minority population. Urban areas have been cited often, for example, for the failure of their police forces to respond equitably to members of minority populations. This has included disproportionate targeting of minorities as potential offenders (racial profiling), a lower level of response to complaints or requests for assistance, or outright disrespect or brutality. While none of these issues is uniquely urban, the concentration of population and the media visibility in a metropolitan area make this an even greater issue of concern.

As already identified, placing a large number of people in a small area increases the risk of health and illness problems. The closer proximity and higher rate of face-to-face contact has a direct impact on the rates of transmissible diseases such as tuberculosis and other respiratory infections. It is no surprise that the resurgence of tuberculosis experienced in the United States in the late 1980s and early 1990s began in New York. The high population density, and the use of large, poorly ventilated spaces as overnight sleeping accommodations for the homeless provided an ideal environment for the transmission of the bacillus. The fact that the public health resources were being strained by the arrival of another condition, HIV/AIDS (human immunodeficiency virus/acquired immunodeficiency syndrome), compounded the problem and meant that drug-resistant organisms were being shared. Health concerns as much as concerns for recreation space have been involved in the development of at least limited open spaces such as parks within concentrated urban areas.

The interrelationships of central urban areas to their surrounding suburbs has been the focus of study and attention from several perspectives. The decreased population density of suburban housing may mitigate some problems that are encountered in older urban settings. For example, there may be more open spaces for recreation or sport, and access to more remote areas is simpler. On the other hand, suburbs mean more widely dispersed individual homes, each needing access to utilities and transportation, and constructed in such a way that neighborhood cohesion may be difficult or impossible to develop. The availability of individual automobile transport in the United States has undoubtedly contributed to suburban sprawl, as have issues of social discrimination. These areas have also grown because of what has been labeled "urban flight": the movement out of cities of the more affluent as new waves of immigrants, often from different ethnic or racial groups, moved in. The apparent cost of maintaining or advancing a standard of living within the urban core was seen as too great. This flight, however, leaves older housing stock to be occupied by those of lower income levels, with less generation of taxes to support services, and the beginning of a downward spiral. When combined with the movement of industry because of restrictions on pollution, search for a cheaper labor pool, or simple displacement due to competition from elsewhere, the result can be a severe, area-wide depression. The cities of the so-called Rust Belt of the northeastern United States provide many vivid examples of this cycle.

Some of the health concerns in urban areas are the result of a loss of individual control. When a person is dependent on either walking or using a private vehicle on a seldom-used two lane road, there is much less need to be concerned about the behavior of others than if the person uses public transportation or walks or drives in a busy urban environment. In addition to the difficulties related to the increased numbers of encounters, there is an increased level of stress, which is known to increase the risk of illness. The density of urban populations and the associated stresses have also been associated with increased rates of violence and, in the second half of the twentieth century, an increase in crime associated with an increase in the distribution, sale, and use of illegal drugs. Some of the crime directly involved the drug distribution networks, as they competed with one another for turf; other crimes were committed by those who became addicted as they attempted to find the resources to support their addictions. For example, one occupational risk that has been studied is the risk of violence to convenience store employees. Of 1,835 robberies of convenience stores in eastern metropolitan areas in 1992 and 1993, 63 percent involved the use of a firearm, and 12 percent were associated with an injury to at least one employee. All five reported fatalities were firearm-related.

A major news story of the late twentieth century was the dramatic success of many urban areas in reducing violent crime. While observers are consistent in saying that no single action can be credited with bringing this about, it may have been the result of a combination of much more sophisticated and targeted policing and a demographic shift that meant a smaller population of young adults, the group most likely to be involved in crime.

Finally, cities are a center of immigration, both from rural areas (as evidenced by the population shift of the last century) and from other countries. Port cities (which may not be coastal in this age of airport travel) experience a constant influx of people from other cultures and climates. This may add to the health challenge in a number of ways. For example, during the period following the end of the Vietnam War in which a large number of refugees from Southeast Asia were arriving in the United States, many health care providers had to learn about an entirely new range of parasitic diseases that were endemic in these people's countries of origin. Beyond specific diseases, immigrants bring different expectations of the health care system, and a different understanding of the range of interventions appropriate to various disease states. Some immigrant health practices have moved toward the mainstream, as in the increasing use of acupuncture, once seen as an odd practice of the Chinese immigrant community. And the increasingly popular herbal remedies are an echo of the role the botanica plays in Hispanic cultures.

HOUSING

Assurance of safe housing has long been an issue for urban areas, and the history of the city is one of many cycles of housing development and reform. Failure to plan for housing infrastructure (water and sewer systems, electricity) when the population is moving into an urban area can result in extensive, substandard housing for those at lower income levels. This can be found in the barrios, favelas, and other overnight city extensions found around many cities in the developing world. In the United States, few such areas are visible (though they are reported to be growing around cities along the Mexican border). Substandard urban housing more often takes the form of older buildings in central city neighborhoods that have not been maintained and are not well-served by public or private services of any kind. Health hazards in such settings include exposure to lead-based paint, cockroach feces (implicated in the increase in asthma), temperature extremes, or unsafe windows and stairs.

In addition to issues of inadequate housing, the combination of a limited supply of affordable housing and low-income levels leaves some individuals and families with no place to call home. The homeless concentrate in urban areas. This may be in part due to the cost of housing in some urban areas, forcing people out of safe housing and into the streets. For example, the economic boom of the 1990s in New York City led to a tightened housing market; those serving the homeless reported a marked increase in families with children finding themselves without a permanent place to live. This has important implications for health care, as homelessness may be associated with a lack of a way to pay for care, and the struggle for safe shelter may obscure early indications of need for care and thus more serious illness problems later on. Housing policy that does not offer ready assistance may also consider a person as having a home as long as there is some extended family member with room on the sofa or living room floor. While such an arrangement may work for a short time under emergency circumstances, the loss of privacy and crowding that results adds another dimension of stress to the risks of mental and physical ill health.

The investment of public funds in housing has met with mixed success. In some cities, the housing provided was poorly matched to the preferences and needs of the people who would be living there, and then allowed to deteriorate to the point that destruction was the only viable option. The implosion of the Pruitt-Igoe Houses in St. Louis, Missouri, in the 1970s was the first widely publicized destruction; many others followed. Other substandard housing has been removed under the guise of urban renewal, but has not always been replaced with appropriately affordable housing. The process of improving housing stock has often led to increases in cost, attracting a more affluent group. This gentrification leaves those at the lower end of the income scale still at risk and without suitable housing. Current public policy in the United States, directed by the Department of Housing and Urban Development, is focused on developing tenants as managers of public housing projects, under the theory that this will increase the likelihood that the property will not be allowed to deteriorate and that those involved in the management process will be learning new skills and improving their place in the general job market.

Another approach to insuring that the entire urban population has safe housing is through subsidies (vouchers) that underwrite a portion of the rent in the general housing market. Landlords are encouraged to participate in the program through tax incentives. News reports have often made much of this program, and of the fact that it may be associated with the integration of racial or ethnic groups that do not typically share neighborhoods. Some neighborhoods have been reported to be extremely resistant and even hostile to this approach; others have been welcoming and found it an enriching experience.

As would be true in rural as well as urban areas, control of indoor temperature is a significant issue. Experiences during periods of extreme heat during the 1990s have led to an increasing awareness of the risks, especially for the elderly or infirm in urban areas, when the temperature remains over 95 or 100 degrees Fahrenheit for several days. Windows may be locked shut for fear of intruders and fans or air conditioning may be seen as an expensive luxury. Neighborhoods attentive to the needs of the housebound during a severe winter (are they frozen in without adequate food? have we made adjustments in the cost of heating so that freezing is unlikely?) have not understood that there were perils at the other end of the thermometer. In areas in which housing is multilevel, and especially where it is high-rise, the isolation of individuals may mean that neighbors do not know who is alone and unable to make appropriate adjustments to either hot or cool weather, and excess media attention to crime and violence may distort views of personal safety and mitigate against cooperation.

FOOD AND WATER

Urban areas offer inhabitants little opportunity to obtain food other than through purchase. The larger the urbanized area, the further foods have to travel to reach stores and eventually households. This also makes "fresh" a relative term: the produce delivered straight from the field to the store is going to be much fresher when the journey is one hour than when it is one day. On the other hand, large concentrations of people make it economically reasonable to regularly import food from all over the globe, making formerly seasonal fruits and vegetables available year-round.

The issue of food availability in urban areas differentiates by income level, as does every other aspect of urban life and health. The cost of space in urban areas makes it less likely that large, modern supermarkets with volume pricing will be available; instead, food is purchased from small neighborhood shops, usually at higher prices. Further, in areas in which many live in smaller spaces (apartments and multiple occupancy buildings of all kinds) there may be less space to store less expensive bulk items. The combined impact of these factors is that the quality and quantity of food available to lower income families in urban areas means they will suffer nutritionally.

Some urban areas have made vacant space available for neighborhood gardens in which both produce and decorative plants may be grown. During periods of population decline or urban renewal, the destruction of buildings makes lots available, and it may be good policy to encourage neighborhood use of the space for gardening. The return of economic development, however, may also abruptly make the land far more valuable as a space for building, leaving the gardeners bereft of land. The issue is not just that of the food produced, which represents only a small proportion of need, but the benefits of open space and positive activities.

Delivery of fresh water to residents was often one of the first public health activities taken up by municipal authorities in the eighteenth century. Using simple surface impoundment, wooden piping, and gravity, water that was not contaminated by urban sewerage and waste products could be made available to central pumps and to individual residences. Over time, the systems have become more elaborate, and contamination concerns have expanded to include not only the infectious diseases of the past and present, but a wide range of potentially damaging chemical agents associated with modern industrial life. The Environmental Protection Agency devotes a substantial proportion of its budget and energy to both the protection of water in its natural state (through the provisions of the Clean Water Act of 1977) and the assurance that drinking water is safe. The capacity of modern laboratories to measure the presence of material in water at a level of very few parts per billion has led to extensive debates about the level of purity that is achievable and reasonable. Whatever the outcome of these differences, it is very clear from mortality and morbidity figures that waterborne diseases in the United States are significantly fewer now than they were a century ago. Water systems need regular maintenance, however, and main pipes installed decades ago remain a regular rupture hazard in older urban areas.

For urban areas, concern about water is not only related to use for human consumption, it is a significant part of safety, given the role that water plays in control of fire. The concentration of housing and industry in urban areas has made fire safety an urban concern since the colonial era. Benjamin Franklin is cited as the father of the modern fire insurance and fire fighting systems in the United States. Urban areas devote an extensive portion of zoning and construction regulation to assuring that heating, cooking, and industrial fires, and electrical transmission systems, are such that the probability of fire is minimized. For example, every building over six stories high in New York City must be equipped with a rooftop water storage tank, assuring a volume and pressure of water adequate for fire suppression, should one occur. Municipalities have also led the way in the development of professional fire departments, with increasingly sophisticated training and equipment. In some communities, fire department personnel are involved not only in fire safety education as a community service, but they are active in health promotion (e.g., blood pressure awareness campaigns) and in a full range of injury prevention and emergency response. Studies done in New York City have also traced the origins of conditions conducive to drug abuse and the spread of HIV infection to decisions made during a time of fiscal crisis to close firehouses. As neighborhoods deteriorated, with fires destroying more buildings before they could be extinguished, boarded-up buildings became shelters for drug dealers and drug users, and the sharing of needles facilitated the rapid spread of the infection.

WASTE DISPOSAL

The concentration of populations in urban areas also means an increased accumulation of waste products. Removal of human waste and garbage is a major commitment in any city, whether the mechanism chosen is completely public or funded by a mixture of public and private resources. The treatment of human waste is costly, and new requirements that protect both people and the environment from contaminants has meant a steady investment in upgrading treatment facilities and building new ones. Treatment plants running at or near capacity in systems in which storm runoff drains into the common sewers may overflow or be bypassed during rainy seasons, causing downstream problems.

Trash and garbage that accumulate in urban areas must be disposed of safely. The old-fashioned garbage incinerator is no longer feasible, due to both volume of material and the air pollution caused by burning. Landfill disposal requires moving the material outside the urban boundary, and safety requirements for landfills have become increasingly stringent. While many areas do not want any waste disposal nearby, the acceptance and processing of urban waste has been welcomed by some economically suffering rural areas. Trash from East Coast urban areas may be moved long distances by land or sea for final disposal. The volume of waste is directly related to the degree of attention paid to recycling of materials. Paper, glass, metal, and plastics all can be returned to use with proper treatment, but efforts to fully recycle met with varying degrees of success. Some urban areas have come very late to full recycling efforts, but most now offer curbside or individual pickup of separated recyclable materials.

At the same time as communities search for more ways to dispose of waste, attention to the siting of waste disposal has increased due to the awareness that racial and ethnic minorities have found themselves disproportionately exposed to these sites. Whether this is because landfills are deliberately located in minority communities, or their proximity is the indirect result of lower income levels and lower property values adjacent to environmental hazards, the practice has fueled both rage and concern, and government action has been taken to address the problem. This issue of environmental justice could be easily expanded to other land-use issues in urban areas, since neighborhoods with lower income levels and greater concentrations of minority populations generally have less open space for parks and playing fields, and the ones they have are often in poor condition. Lack of safe park space leaves low-income urban children playing in the street or other unsafe areas, increasing chances of injury.

Both air and noise pollution are of great concern in urban areas. In the United States, the Clean Air Act (1970) authorized the Environmental Protection Agency to take a number of steps to reduce pollutants, and there were notable improvements in the last part of the twentieth century. These changes have affected both industry (and may have driven manufacturing away from population centers) and private lives (in transportation changes). The need to move large volumes of materials into urban areas, and to move large numbers of people around within urban areas, means that the search to devise more environmentally sound and quiet means of locomotion and transportation will continue. The attachment to motor vehicles that has come over the last century poses a substantial barrier to needed change, however. As with the changing attention to drinking water, people must be concerned not only with visible particulate matter (smoke and ash from fireplaces) but with a wide range of chemicals associated with the increase of chronic disease.

HEALTH AND HEALTH SERVICES

Urban hospital systems have provided a critical link in access to health care. Many have a long history of service that dates to the waves of immigration and the epidemics of communicable diseases during the nineteenth and early twentieth centuries. Those that are publicly owned have been particularly important because of their continuity of presence, visibility, and obligation to serve all within the jurisdiction. One example of the continuing evolution of such systems is the shift from a combination of inpatient care, specialty clinics, and emergency rooms to community partnerships featuring community-oriented primary care. Shifts in payment approaches by public insurances such as Medicaid's use of prepaid group coverage requires adaptation to global and capitation payment methods, and has drawn some traditional patients (and their money) away from these public hospitals, leaving them strapped financially but still serving an essential function in urban areas.

While there are many negatives to health and health services in urban areas with large uninsured populations and antiquated care systems, there are also positives associated with urban health. The concentration of people means that specialized services are economically viable. It is medical services in urban centers that have pioneered many of the interventions now taken for granted and that are now being transferred to less populated areas. The person with a relatively unusual condition who lives in an urban area is more likely to find the needed care within close proximity than a similar individual in a rural location.

Urban areas have been leaders in developing services for the homeless and services targeted to individual racial and ethnic groups. For example, the United States Indian Health Service has supported the development of urban clinics to provide health services for the large numbers of Native Americans living in urban areas who are cut off from culturally appropriate services that would be available on reservations. In neighborhoods without an adequate supply of health services, funding from the Health and Human Services Administration and the Substance Abuse and Mental Health Services Administration have allowed the creation of community-oriented ambulatory care programs. Services supported with these funds must have boards that include representatives of the community being served, and they have been marked by a high degree of acceptance.

In addition to services set up for the diagnosis and treatment of individual patients, urban health services also have a population-wide focus, provided by each jurisdiction's public health agency. These services are intended to prevent epidemics, protect against environmental hazards, prevent injury, promote and encourage healthy behavior, respond to disasters, and assure the quality and accessibility of health services. They date to the late nineteenth and early twentieth centuries, and had their beginnings as a response to epidemics such as typhoid and cholera. They continue to play an important role, though the diseases of interest have expanded. Today an urban health department (which may be several agencies, depending on local preference) monitors HIV infection, tuberculosis, asthma, diabetes, violence, child safety, tobacco control, suicide prevention, family planning, nutrition, and immunizations. The line between the services offered by a health department and those available from other publicly supported health services is an arbitrary one. In order to prevent disease and promote health, individuals must have access to personal care, and when it is not available elsewhere, the public health agency may provide it, at least in urgent circumstances. But where there are other resources for care, the public health agency can focus on system-level actions that will limit exposure of the population to risk factors and support health for all. This is best done in collaboration with citizen groups and other public health entities in an organized way. The Healthy Cities/Healthy Communities movement of the 1990s is one example of resources available to those interested in improving health.

Urban health is a complex web of both threats to health and supports to health. It cannot be understood apart from an appreciation for the size and density of the populations involved, and it continues to evolve as economics shift, technology advances, and public expectations develop. But the likelihood that urban areas will continue to concentrate people, problems, and opportunities makes its health concerns unique and important.

Kristine Gebbie

(see also: Boards of Health; Clean Air Act; Clean Water Act; Community Health; Drinking Water; Environmental Determinants of Health; Environmental Justice; Ethnicity and Health; Healthy Communities; Inequalities in Health; Social Determinants; Substance Abuse; Urban Social Disparities; Urban Sprawl; Urban Transport; Violence; Wastewater Treatment )

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