Suburban Sprawl causes health risks?

Washington Post:

People who live in sprawling communities tend to suffer more health problems, according to the first study to document a link between the world of strip malls, cul-de-sacs and subdivisions and a broad array of ailments. The study, which analyzed data on more than 8,600 Americans in 38 metropolitan areas -- including the Washington region -- found that rates of arthritis, asthma, headaches and other complaints increased with the degree of sprawl. Living in areas with the least amount of sprawl, compared with living in areas with the most, was like adding about four years to people's lives in terms of their health, the study found.

This seemed pretty fishy to me. The first rule to remember with statistics is the correlation does not equal causation. The article does quote a few skeptics of the study toward the end:

"I remain a skeptic of the research, in part because the results they find are weak," said Samuel R. Staley, a senior fellow at the Reason Foundation, a Los Angeles-based libertarian group. "This study seems particularly prone to spurious results -- results that are statistically related but really don't tell us much about causes." Peter Gordon, a professor in the school of policy, planning and development at the University of Southern California in Los Angeles agreed, calling the study "junk science." The areas studied, for example, are so large they could not distinguish important neighborhood differences, he said. "Describing places this large via a simple ad hoc 'sprawl' index is nuts," Gordon wrote in an e-mail. "People have been suburbanizing for a very long time. Yet, life expectancy keeps getting longer."

I agree fully that the lifestyle of many people (myself included) in the suburbs isn't very healthy. Fast food and little exercise is an obvious bad health choice to make. I don't know that you can conclude that this is caused by the suburbs however.