How do cities affect our health? A newly published research report from MIT’s Center for Advanced Urbanism (CAU) highlights the complexity of the issue. Produced in collaboration with the American Institute of Architects, the document examines an array of public health matters in eight major metropolitan areas in the United States, and suggests a wide array of possible remedies, from better mass transit to extensive tree-planting. The report was principally authored by Alan Berger, a professor of landscape architecture and urban design, along with Andrew Scott, an associate professor of architecture; about a dozen graduate students from MIT’s School of Architecture and Planning and researchers at CAU also worked on the project. Berger sat down with MIT News to talk about the findings.
Q. What did you learn from undertaking this project?
A. The number one thing I’ve learned is: You cannot prove causality easily, because the issue is so complex. If someone says to you that suburbanites are heavier because they drive more, it’s not been proven true. The studies [on this] are actually fairly soft. If you look at these eight cities, 83 percent of the suburban counties ranked healthier than their central city, using widely accepted health-risk factors. Some public health officials believe that proximity to medical facilities always leads to better public health, but when you start mapping those cities — Houston, for example — some of the worst health is in neighborhoods near the highest density of medical facilities.
Also, the idea of the food desert is largely fiction. There’s access to decent food pretty much across the metropolitan areas. In our cities the proximity to fast food doesn’t directly lead to poor urban health; there’s proximity to fast food everywhere. The question is how you get people to choose the right foods. These are all opportunities for us to build the knowledge base.
Q. Does that make it harder to advocate for certain measures, given that causality is a bit cloudy?
A. One of the main things we learned from this study is that there is no silver bullet for urban health. Every city has different socioeconomic and physical layout issues. So the solution to make urban health better is going to [vary] in every city. One of the reasons we wrote the report was to give people a sense that the silver-bullet mentality, from technological or policy perspectives, needs to stop.
But once you understand the whole urban fabric, you can understand where you want to work. Los Angeles has the widest continuous dense patch of human beings in the United States. Obviously it’s dominated by automobiles. In July 2011, they were doing construction on Highway 405, which is the busiest highway in the United States, and they shut the highway down for the weekend. Air quality improved by 85 percent in 24 hours.
When you take that into a planning and design perspective, packing that corridor with new growth would put people into the highest-particulate air in the United States. That’s where the power of design shows up. You don’t have to give up density, but you can do it in a way to protect people, to mitigate the problems. Setting buildings on the outer edges of the right of way can help, and using landscape to filter out a lot of particulate matter may provide more health benefits than standard building codes require. If you apply design ingenuity and health knowledge, you can think about how to do it in a better way.
Q. So in a sense, you need to step back, look at the whole urban framework, and apply a series of remedies?
A. Yes. If you really want to look at urban health, you have to look across the entire metropolitan area that’s been urbanized in order to address the systems that make it perform. You can’t look at a building without thinking about how people get to that building. The holistic way we look at cities here at MIT is that a city is a metropolitan area with all kinds of different fabrics, in terms of transit, economics, industry, the environment, and more.
Many people still think that in cities, all the jobs are downtown. We know from doing years and years of research in this department that there are actually more jobs created that are not in the downtown now; they’re across these metropolitan areas. In the United States, more people now commute between two suburbs, to go from home to work, than to a downtown. We have to look at a much broader picture. About 67 percent of Americans live and work in suburbia.
The whole profession of city planning evolved out of solving sanitation problems during the late 19th and early 20th centuries. The public health field then went toward disease management, and city planning went in another direction, and they never came back together. We’re trying to get public health officials, designers, planners, and engineers in the same room to talk and come up with better solutions, and we want them all to be thinking across disciplinary boundaries.