Healthy City Living
Are suburbs making us sick?
Urban Sprawl and Public Health: Designing, Planning, and Building for Healthy Communities, by Howard Frumkin, Lawrence Frank, and Richard Jackson, Washington, D.C.: Island Press, 338 pages, $30
During the summer, we often pack up our kids for a little sun and fun at the local pool, nestled in our low-density, sprawling suburb in the Midwest. My kids eat a balanced diet, are physically fit, and are certainly not overweight. The pool is one of our tactics for moderating their time in front of video games and the television. It also ensures that they get a little exercise.
Each year we're surprised to find that other parents don't see things the same way, at least to judge by their children's girth. As our kids frolic, we sit amazed that other parents let their overweight children walk up to the snack bar to consume ice cream, hot dogs, and other high-calorie snacks. We know American kids face an obesity problem—we see it every summer in the jiggling rolls of sunburned fat at our local pool.
So I welcome any book that wants to inform the public about ways to keep us and our children fit. That's what the authors of Urban Sprawl and Public Health seem to promise. Unfortunately, the book doesn't deliver, partly because authors Howard Frumkin, Lawrence Frank, and Richard Jackson can't solve the problems we see every summer.
They are, to be sure, well qualified to write this book. They are among the most prolific researchers on the subject of land use and public health, and they have strong credentials: Frumkin chairs Emory's Department of Environmental and Occupational Health, Frank holds an endowed chair in transportation planning at the University of British Columbia, and Jackson is an officer in California's Department of Health Services. And their book's basic premise is plausible: Choices about where and how people live have potentially significant implications for their health. Living on top of a toxic waste dump, to pick an obvious example, probably increases the odds of getting cancer.
The large lots with segregated residential and commercial land uses perpetuated by standard zoning codes and planning procedures work against good health, Frumkin and his colleagues argue. Low-density suburbs, they say, encourage automobile use and discourage walking, contributing to sedentary lifestyles while disrupting healthy fitness habits and spewing more pollutants into the air. Unfortunately, the evidence they provide isn't nearly as convincing as they claim, and they miss an opportunity to discuss how everyday habits such as dipping into a bag of potato chips after work (or school) or plopping down in front of the TV contribute to the health problems that concern them.
The opening chapters provide useful, objective overviews of how recent North American land use patterns have evolved. We started out on farms and the frontier, but rapid productivity gains and the industrial revolution crammed people into dense, congested cities. This migration created its own problems: poor sanitation, epidemics, stifling air quality, overcrowding. The lure of the countryside prompted the wealthy and then the middle class to move jobs and homes out.
Land has always been romanticized in American culture and literature, the authors point out. Cities were dirty, crowded, and unhealthy; the push into the suburbs was a natural response to the worst aspects of city life.
Outward expansion was encouraged by revolutionary changes in transportation, first the trolley car and then the automobile. The introduction of low-cost construction methods made new housing cheap, and abundant land outside the city center made housing more affordable in low-density areas. Suburbs were in some ways inevitable destinations for the North American working class and a growing middle class.
Things changed dramatically after World War II. The interstate highway program, the authors claim, subsidized automobile use and travel, making suburban areas more accessible. Federal financing made mass-production suburbs like Levittown possible, and zoning and planning effectively locked in place low-density lifestyles that segregated residential and commercial uses. The effect, they suggest, was the destruction of the urban neighborhood.
Frumkin and his co-authors argue that low-density housing patterns created a new set of public health challenges. In addition to the health problems associated with dense cities, they say, regions now confront sprawl-induced problems with air quality, obesity, traffic deaths, water quality, and mental stress, along with a loss of community (or "social capital") and an inability to address the health issues of specialized groups such as children, the elderly, and the disabled.
The authors provide a service by pulling together the growing body of academic research examining links between land use and human behavior in an accessible and readable way. But their conclusions often do not adequately reflect the richness and complexity of the research. In some cases, the contrary evidence is so obvious that knowledgeable readers will be scratching their heads, wondering why the authors don't address countervailing data.
If urban sprawl destroys air quality, why has air quality improved in every major metropolitan area in the same period that North American cities have sprawled the most? Ozone in the Los Angeles basin, for example, has been cut in half since 1973, according to the South Coast Air Quality Management District. If living in automobile-oriented suburbs increases the risk of personal injuries, why are fatality rates for commuter and light rail transit two times higher than for urban roads and almost three times higher than urban interstate highways? If automobile injuries and fatalities are a significant drawback of suburbs, why aren't the higher risks of property and violent crime significant drawbacks of dense, mixed-use, transit-oriented cities?
If this book were a polemic, Frumkin, Frank, and Jackson could perhaps be excused for ignoring countervailing evidence. But Urban Sprawl and Public Health is supposed to serve as a guide for citizens, planners, architects, landscape architects, and legislators.
The authors do note some of the paradoxes in their research, and they seem genuinely perplexed. On the one hand, they believe communities should be designed for higher densities to encourage walking or bicycling to work. On the other hand, higher densities expose neighborhoods to higher levels of pollution at the street level. Walking and bicycling expose people to that pollution longer, and they breathe polluted air at higher and more intense rates. High densities can reduce pollution only if significant numbers of people opt for slower, less flexible public transit over the mobility and speed of cars. Yet the flexibility and speed of the automobile still trumps transit in most high-density areas. Even in dense, congested, mixed-use London, England, with its extensive public transport system, almost half of all trips are by automobile.
The weakest part of the book is not its summary of the literature. It's the discussion of an area where none of the authors has much professional expertise: urban planning. Achieving their vision of cities—high-density, mixed-use, pedestrian-friendly, mass-transit-dependent neighborhoods—would require the kind of draconian housing, migration, and land use regulations they disavow in their preface. They proclaim: "We do not argue for removing choices; rather, we argue for more choices. It would be foolish to tell anybody where to live." Yet this is exactly what would have to happen to achieve the changes in lifestyle and land use patterns necessary to obtain significant health benefits.
Judging from what people actually buy and what they say in consumer surveys, most families prefer to own their own homes with yards large enough for their kids (or future kids or grandchildren) to play in. The density of a typical U.S. suburb ranges from 2,500 to 3,000 people per square mile. By contrast, professional planners estimate that effective bus transit becomes viable at 10,000 people per square mile. Light rail becomes viable at 14,000 people per square mile.
Any way you slice it, that's a major restructuring of the urban landscape, and it represents a significant move away from the preferred housing of most households. Rather than buying a 1,500-square-foot house on a quarter-acre lot, a lower-middle-income household will be buying a 1,000-square-foot townhouse or duplex. The families that will be limited the most will be lower- and middle-income households and first-time homebuyers. This rejiggering of the urban landscape seems pretty dramatic for the relatively small health benefits it might bring.
At times even the authors recognize the limited impact of the built environment on public health. They write, for example, that moving from the lowest-density metropolitan area to the highest-density metropolitan area in the United States reduces the probability of being obese by just 12 percent. Yet this qualification doesn't stop them from claiming that sprawl is a major factor in America's obesity epidemic, providing further justification for government control over housing and land use.
Frumkin, Frank, and Jackson display a classic analytical fallacy: comparing an ideal construct to the gritty reality of the way people actually behave. Real people don't have the luxury of choosing idyllic settings. Owning a house with a large yard may mean I live too far from the grocery store to walk, but it provides a safe haven for my children to play in with their friends in the immediate neighborhood. I'm not forced to organize a trip to the public park, holding their hands tightly, food and toys strapped to my back, as we cross a busy urban street. I may be more distant from my neighbors, but I'm at less risk of being robbed or assaulted. Suburban cities are much safer than traditionally denser urban cores, reporting victimization and crime rates at one-third to 50 percent lower, according to the FBI's Bureau of Justice Statistics. Victimization by strangers is also lower in the suburbs.
All of which brings us back to my community pool, and to the opportunity this book missed. Frumkin and his colleagues are fundamentally right that different problems emerged with different types of cities at different points in time. Large, dense urban centers faced significant problems, but these problems were solved through technological innovation, advances in health care, the establishment of urban sewer systems, and the economic shift away from heavy industry.
Modern suburbs pose new challenges. Community design may play an important supporting role in improving health, but larger, often unknown forces may exert more powerful influences on human health and behavior. Air quality has improved, notes the American Enterprise Institute's Joel Schwartz, because fleet turnover has removed the cars that pollute the most. High density and mixed uses may raise the likelihood that children will walk to the store or to a neighbor's house, but these effects are likely to be swamped by general trends toward poorer eating habits and more reliance on sedentary entertainment such as video games.
The active, overweight kids at my local community pool don't fit into the public health model of community design advocated by anti-sprawl academics like Frumkin, Frank, and Jackson. They reflect a general reluctance on the part of parents and consumers to understand and respond to the health challenges implicit in lifestyles characterized by more wealth, greater consumer choice, higher mobility, and abundant land. A good book on sprawl and public health would also recognize the centrality of consumer choice and the productive capacity of market economies. That book, alas, has yet to be written.