2
Rebuilding the Unity of Health and the Environment*

Richard J. Jackson

Our discussion of rebuilding the unity of health and the environment in the southeastern United States logically begins with the definition of “health.” The World Health Organization defines health as “a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity” (World Health Organization, 1986). Changes in society in the past 100 years have caused us to broaden our definition of health, to expand the role of public health, and to recognize the connection between the environment and health.

Life expectancy in the United States has increased by nearly 30 years in the last 100 years (Centers for Disase Control and Prevention, 1999a). Most of that improvement has come from basic public health measures, such as sanitation, an improved economy, and better housing. Only about seven years are attributed to improved medical care (Bunker et al., 1994). During the same 100 years, the diseases that cause our death have changed dramatically. We seldom die from communicable diseases such as pneumonia, diarrhea, and tuberculosis. We die more often from chronic diseases, such as heart disease, cancer, and lung disease, and from injuries (Centers for Disease Control and Prevention, 1999b). This shift in the major causes of death has presented new challenges for public health agencies. Concepts such as sedentary life-styles, automobile use, diet, and urban sprawl are found increasingly in the vocabulary of public health officials.

During the past 30 years, Americans have benefited greatly from environmental regulations and laws concerning air quality, water quality, waste disposal, and toxic exposure. An example of positive change is the reduced levels of toxic chemicals in the population. The average blood lead level of people in the United States is now 2 µg/dL. Before the passage of the Clean Air Act of the 1970s and the removal of lead from gasoline, the level was 20 µg/dL—enough to reduce IQ scores by 4 to 5 points (Grosse et al., 2002).

Although we welcome these changes, we have in some sense lost touch with

*  

This chapter is an edited transcript of Dr. Richard Jackson’s remarks at the workshop.



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Health and the Environment in the Southeastern United States 2 Rebuilding the Unity of Health and the Environment* Richard J. Jackson Our discussion of rebuilding the unity of health and the environment in the southeastern United States logically begins with the definition of “health.” The World Health Organization defines health as “a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity” (World Health Organization, 1986). Changes in society in the past 100 years have caused us to broaden our definition of health, to expand the role of public health, and to recognize the connection between the environment and health. Life expectancy in the United States has increased by nearly 30 years in the last 100 years (Centers for Disase Control and Prevention, 1999a). Most of that improvement has come from basic public health measures, such as sanitation, an improved economy, and better housing. Only about seven years are attributed to improved medical care (Bunker et al., 1994). During the same 100 years, the diseases that cause our death have changed dramatically. We seldom die from communicable diseases such as pneumonia, diarrhea, and tuberculosis. We die more often from chronic diseases, such as heart disease, cancer, and lung disease, and from injuries (Centers for Disease Control and Prevention, 1999b). This shift in the major causes of death has presented new challenges for public health agencies. Concepts such as sedentary life-styles, automobile use, diet, and urban sprawl are found increasingly in the vocabulary of public health officials. During the past 30 years, Americans have benefited greatly from environmental regulations and laws concerning air quality, water quality, waste disposal, and toxic exposure. An example of positive change is the reduced levels of toxic chemicals in the population. The average blood lead level of people in the United States is now 2 µg/dL. Before the passage of the Clean Air Act of the 1970s and the removal of lead from gasoline, the level was 20 µg/dL—enough to reduce IQ scores by 4 to 5 points (Grosse et al., 2002). Although we welcome these changes, we have in some sense lost touch with *   This chapter is an edited transcript of Dr. Richard Jackson’s remarks at the workshop.

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Health and the Environment in the Southeastern United States the vision of what we want our urban environment to be and what quality of life we want to attain. For hundreds of years, people have known how to build urban environments that are dense and also pleasing to human beings—cities in which people feel connected to each other. High urban density is not invariably associated with negative effects on physical or mental health. People enjoy cities with architecturally diverse three- and four-story buildings that encourage and welcome them to walk around—cities such as London and Paris. People enjoy living and working near parkland and cool green spaces and value these natural assets. By contrast, the urban sprawl in the metropolitan areas of our country is characterized by features that detract from the enjoyment of natural and man-made surroundings and reduce the sense of community (Box 2–1). Box 2–1 What Is Sprawl? Sprawl is a pattern of urban regional development that features the following: Land-extensive, low-density, leapfrog development Segregation of land uses Extensive road construction Architectural homogeneity Economic and racial homogeneity Shift of development and capital investment from inner cities to the periphery Absence of regional planning What has caused us to diverge so dramatically from the age-old urban design features that were so pleasing in earlier eras? What factors have led to the acceleration of urban sprawl that we are experiencing here in Atlanta and in other U.S. cities? The answers to these questions may help us understand what we can do to modify our design of urban areas, use of natural resources, and life-style behaviors to create a healthier and more livable urban environment. Many forces, including cheap land, technological advances, and social policies, have combined to drive migration from cities to suburbs, creating what some have characterized as a “suburban nation.” In Atlanta, the main factor that has influenced urban sprawl is population growth. The population of the Atlanta area has tripled in the past 50 years (Brookings Institution, 2002a), and this rapid growth has placed strains on the natural and human environment. Ominously, the entire U.S. population is expected to more than double in this century, reaching 571 million by the year 2100 (U.S. Census Bureau, 2000c). The environmental issues that may seem remote today will be brought dramatically to the forefront. A burgeoning population is one reason that many cities, including Atlanta, have become very difficult to live in. Commutes have doubled and tripled, and for many people, urban life has become taxing.

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Health and the Environment in the Southeastern United States Box 2–2 How Might Urban Sprawl Affect Health? Increased air pollution Increased heat Decreased water quality and quantity Reduced physical exercise More automobile crashes More pedestrian injuries Mental health consequences Decreased social capital Urban sprawl not only has considerable direct and indirect consequences for the environment, such as loss of forests and depletion of waterways, it also has consequences for human health in at least eight areas (Box 2–2). The first area, air pollution, is a growing health problem in our cities. In Atlanta, high ozone levels are a particular health hazard. Ozone air pollution inflames the airways, affects the immune system, and increases the risk of heart disease and lung disease (Committee of the Environmental and Occupational Health Assembly, 1996). Emergency department admissions nationwide have been shown to increase by 40 percent during ozone alert days (Committee of the Environmental and Occupational Health Assembly, 1996). Despite the obstacles of rapid population growth and decreasing air quality, the behavioral choices we make can positively affect our environment and our health. For example, to avoid traffic congestion during the Atlanta Summer Olympics in 1996, many people stopped driving and used the city’s rapid transit system. The air quality in Atlanta improved by about 30 percent during that time (Friedman et al., 2001). People were in a good mood. Tremendous crowds filled the downtown area. The city was more fun to live in when the air was cleaner, and it was also a healthier city. Children’s acute care visits to medical clinics and pediatric emergency departments for asthma decreased, and hospital admissions for respiratory diseases declined throughout the city (Friedman et al., 2001). Another health hazard posed by urban sprawl is the effect of heat. On warm days, urban areas can be 6 to 8°F warmer than surrounding areas, an effect known as the urban heat island. This effect is caused by two factors. First, dark surfaces, such as roadways and rooftops, efficiently absorb heat from sunlight and reradiate it as thermal infrared radiation; these surfaces can reach temperatures that are 50 to 70°F higher than the surrounding air. Second, urban areas are relatively devoid of vegetation, especially trees, which would provide shade and would cool the air through “evapotranspiration.” In Atlanta, urban sprawl has featured precisely the changes that expand our urban heat island: clearing trees and building large areas of roofs and roadways

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Health and the Environment in the Southeastern United States FIGURE 2–1 Atlanta’s heat island. Scientists from the National Aeronautics and Space Adiministration have discovered that Atlanta’s sprawl development pattern is creating thunderstorms. SOURCE: American Forests, reprinted with permission. (Figure 2–1). On a warm, 80°F day in Atlanta, the temperature of a concrete airport runway may reach 84°F, an old asphalt road might reach 98°F, and a freshly blacktopped parking lot might reach 102°F (Quattrochi et al., 1998). The health effects of heat are well known (Nadel and Cullen, 1994). Relatively benign disorders include heat syncope, or fainting; heat edema, or swelling; and heat tetany, a result of heat-induced hyperventilation. Heat cramps are muscle spasms that occur after strenuous exertion in a hot environment, and heat exhaustion is a more severe acute illness. The most serious condition is heat stroke, which represents a failure of the body to dissipate heat and can be fatal. Heat also has indirect effects on health that are mediated through air pollution. Ozone formation from its precursors, NOx and hydrocarbons, is enhanced by heat. Also, as heat increases, the demand for energy to power air conditioners rises, requiring power plants to increase their output. The increased demand results in greater production of the pollution that these plants generate, including particulate matter, SOx, NOx, and air toxics. Urban design features can reduce the amount of heat in our cities. For example, a light-colored roof on a home reduces heating and cooling costs by about 15 to 20 percent (U.S. Department of Energy, 2002). Planting vegetation around homes can reduce energy costs by as much as 25 percent (U.S. Department of Energy, 2002). Not only do trees remove CO2 and produce oxygen, they also cool our environment. Trees and other vegetation slow the runoff of water into streams, allow groundwater recharge, and make the environment more attractive for walking and other physical activities. It is eminently clear that we should safeguard our trees. Yet in the Atlanta region, we have been removing an average of 55 acres of trees every single day, and we have been doing this for 20 years (Quattrochi, 2000). Removing trees and paving the land have another detrimental effect on health. They diminish water quality. During the first rain after 10 or 12 dry days, the oil, tire rubbings, crushed tire-balancing lead weights, dust, and antifreeze that have accumulated on our asphalt roadways and parking lots are swept into culverts and drains—and ultimately end up in the river. Reducing the amount of runoff in our rivers has genuine health benefits. The Centers for Disease Control

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Health and the Environment in the Southeastern United States and Prevention (CDC) is conducting several studies on the health effects of contaminants in drinking water. Water engineers may tell us that our water meets all requirements for water quality. Yet our water is sampled for less than 10 percent of the carbon materials it contains. The other 90 percent of these materials are unidentified and untested. Our drinking water may meet all current standards, but these standards may not be stringent enough to safeguard our water quality because we tend to evaluate only what we can measure easily. A recent decision by New York City officials provides an example of an environmentally sound means of improving water treatment. City officials were recently faced with the need to build a $5 billion water treatment plant with an estimated annual operating cost of $200 million for water-purifying chemicals and maintenance. Instead of building the plant, they spent only about $100 million buying buffer land around their main reservoirs in the Catskill region. In so doing, they maintained their water quality for far less cost without requiring much increase in the level of water treatment, and they preserved the watershed lands at the same time. A further effect of urban sprawl on health is the enormous increase in auto use and the crashes that inevitably follow. In the Atlanta area, we drive 95 million miles each day, enough to drive to the sun and part way back—an average of 36.9 miles for each man, woman, and child in the region, including non-drivers (Lomax et al., 2001). We waste 136 million hours waiting in traffic, or an average of an hour a week for each of us—equivalent to a year’s worth of full-time work from 68,000 people (Lomax et al., 2001). We waste 214 million gallons of gasoline, contributing to local and regional air pollution and to global levels of CO2 (Lomax et al., 2001). Traffic-related injuries are the leading cause of death among young people in the United States (National Highway Traffic Safety Administration, 1999), and motor vehicle crashes alone account for more than 40,000 deaths a year (CDC, 1999). Automobile fatality rates vary across cities (Table 2–1). In 1998, Atlanta led the list with about 13 deaths per 100,000 people (National Highway Traffic Safety Administration, 1999). Because driving is so dangerous, we might imagine that people would be safer walking. Statistics prove otherwise. Annual pedestrian fatality rates among major cities in the United States show about 1.9 fatalities per 100,000 people in Philadelphia, 4.6 per 100,000 in San Francisco, and 6.4 per 100,000 in Atlanta (Table 2–1) (National Highway Traffic Safety Administration, 1999). What accounts for the differences? Some cities, such as Atlanta, are tough Our urban environment discourages many forms of beneficial physical activity, as driving replaces walking and bicycling, and as roadways are built without sidewalks, paths, and safe pedestrian crossings. Richard Jackson

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Health and the Environment in the Southeastern United States TABLE 2–1 Automobile and Pedestrian Fatality Rates in U.S. Cities City Automobile Fatality Rates per year 1998 (deaths per 100,000 people) Pedestrian Fatality Rates, 1998 (deaths per 100,000 people) New York 2.51 2.33 San Francisco 3.76 4.55 Philadelphia 5.36 1.88 Portland 6.55 2.58 Houston 9.8 3.41 Phoenix 10.52 4.09 Dallas 11.33 4.28 Atlanta 13.12 6.44   SOURCE: National Highway Traffic Safety Administration, 1999. towns to walk in. Many areas have no sidewalks and no way to get around on foot. The state of California has addressed this problem by setting a goal that every child ought to be able to walk or bicycle safely to school. Officials hope to achieve this goal by using a set-aside of highway funds to build routes so that children can get to school unharmed. While increasing our calorie consumption, we have dramatically reduced our physical activity. Being sedentary carries a two- to threefold increase in the risk of early death and a three- to fivefold increase in the risk of dying from heart disease (Wei et al., 1999). The effect of low physical fitness is comparable to that of hypertension, high cholesterol, type II diabetes, and even smoking (Blair et al., 1996; Wei et al., 1999). Conversely, physical activity prolongs life (Lee and Paffenbarger, 2000; Wannamethee et al., 1998), and it also benefits health indirectly, through its effect on body weight. The United States is currently suffering an epidemic of overweight, which has advanced rapidly in the last two decades. Two-thirds of the U.S. adult population is now considered either overweight or obese (Mokdad et al., 1999). Overweight and obesity are risk factors for a wide range of health problems, including cardiovascular disease and cancer (National Institutes of Health, 1998). Although sprawl does not fully account for our increasingly sedentary lives and our national epidemic of overweight, it is an important contributor to these expanding health problems. The combination of health hazards in urban areas poses a dilemma for health professionals who counsel urban dwellers on healthy behaviors. For example, how can we promote outdoor physical activities when to do so may place people at risk for exposure to high ozone levels, excessive heat, and pedestrian injuries? Encouraging the pursuit of healthy behaviors in an unhealthy environment sends a mixed message.

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Health and the Environment in the Southeastern United States Our mental health is another area that is affected by urban sprawl. For example, there is considerable evidence that commuting is linked to back pain, cardiovascular disease, and self-reported stress (Koslowsky et al., 1995). As people spend more time on more crowded roads, an increase in these adverse health outcomes might be expected. One indicator of mental distress related to driving is road rage, defined as “events in which an angry or impatient driver tries to kill or injure another driver after a traffic dispute” (Rathbone and Huckabee, 1999). Road rage appears to be increasing (Mizell, 1997), and the reasons for it are not well understood. Stress at home or work may combine with stress while driving to elicit anger (Harding et al., 1998; Hartley and el Hassani, 1994). Long delays on crowded roads are likely to be a contributing factor. If road rage reflects the stress that accompanies frequent, long, and difficult commutes on crowded roads, it indicates another manner in which sprawl may threaten both mental and physical health. Exercise preserves both physical health and mental health. Studies show that physical activity has a beneficial effect on symptoms of depression and anxiety and that it improves mood (U.S. Department of Health and Human Services, 1996). Depression is associated with low levels of serotonin. Some studies indicate that higher levels of physical activity can significantly raise serotonin levels and that physical activity is as effective for combating depression as some selective serotonin reuptake inhibitors (SSRIs) that are prescribed for this condition. A helicopter could drop you at any one of 100,000 intersections, and you would have no idea whether you were in Maine or Virginia, or anywhere else in the United States. Richard J. Jackson Again, our urban environment hinders us from taking part in many forms of beneficial physical activity. For example, the CDC offices in Atlanta are located on a busy highway with no sidewalks. As beneficial to health as bicycling would be, it would be suicidal for a CDC employee to bicycle to work, because doing so requires riding in a gutter next to six lanes of traffic. Not only is this road dangerous, it is ugly. As James Howard Kunstler (1996) writes in his book Home from Nowhere, “We drive up and down the gruesome, tragic, suburban boulevards of commerce, and we are overwhelmed by the fantastic, awesome, stupefied ugliness of absolutely everything in sight. It’s as if the urban environment has been designed by some diabolical force, bent on making human beings miserable.” A helicopter could drop you at any one of 100,000 intersections, and you would have no idea whether you were in Maine or Virginia, or anywhere else in the United States. We have created a depressing environment that makes us glum about the future of civilization. Although being glum may not strike us as being very serious, we must remind ourselves that the leading chronic disease of American

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Health and the Environment in the Southeastern United States FIGURE 2–2 The use of antidepressant drugs has increased from 1988-1998. SOURCE: Foote and Etheredge (2000). Reprinted with permission from IMS Health, Inc. adults is depression. Any practicing clinician will tell you that probably half of all medical patients have some concurrent depression or mental health disorder. The dramatic rise in the consumption of prescription antidepressants over the last ten years suggests that depression, too, has reached epidemic proportions in our society (Figure 2–2). What are the treatments for depression? The obvious answers are taking medication, establishing effective social interactions, and psychotherapy, but pursuing physical activity is also an effective treatment. In cities such as Washington, D.C., and New York, taking a long walk is fairly easy. In Atlanta, we have designed an environment that penalizes people for pursuing physical activity. A final effect of urban sprawl on health is the diminution of social connectedness, or social capital, which is an accumulation of social networking, civic engagement, and shared trust and reciprocity. Numerous writers have observed a loss of social capital in recent years (Etzioni, 1993; Putnam, 2000), and some authors have attributed this decline, in part, to suburbanization and sprawl (Calthorpe, 1993; Mo and Wilkie, 1997). How do we approach this set of problems? Those of us in environmental health have spent considerable time over a long period looking at environmental issues in a very narrow way, and at the same time feeling as if the larger environment in which we live is becoming more difficult to control and less connected to human needs. The purpose of this meeting is not so much to focus narrowly on specific issues, such as toxic exposures, but to promote exploration of the larger issues of how the environment influences our total health—physical, men-

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Health and the Environment in the Southeastern United States tal, and social. Such a holistic effort will enable us to make the connections between health and the environment and to nurture our natural environment, design our built environment, and strengthen our social environment in ways that will promote better health.