Health and the City
Contrary to ideas about urban sprawl, a study from USC’s Lisa Schweitzer finds that air pollution exposure is worse in dense cities.
Public health researchers have encouraged urban planners to reduce sprawl in an effort to address poor air quality and the impacts of climate change. They argue that smarter, more compact development can reduce driving and the resulting levels of particulates and pollution.
However, a new study by Lisa Schweitzer of the USC School of Policy, Planning, and Development concludes that, contrary to current thinking, exposure to poor air quality is higher in compact U.S. areas than in sprawled locations.
According to Schweitzer, the amount of pollution or driving in a region is only part of the story.
Take the case of Los Angeles. There, compact developments have been built to ensure that residents have environmentally smart transit access. But some of those apartment buildings were built next to freeways, where pollutants can be at their peak. With their multifamily housing and low-income residents, these developments earned the title “Black Lung Lofts” from L.A. Weekly.
Schweitzer’s study illustrates that the problem can be worse in compact areas than in sprawl. It also finds that vulnerable populations like the poor, senior citizens and children have higher exposures to pollution in compact regions.
Compact development or infill is a good strategy, but location matters. High population density isn’t a problem if the air is, on average, as good as it is in Santa Monica. It only becomes a problem when the air quality is already poor — such as in Long Beach, where high population density will only increase the number of people exposed to high concentrations of particulate matter.
Schweitzer believes that policy and planning need to factor in recent studies from the engineering and climate science fields in order to acquire a better understanding of how pollution affects neighborhoods. Planners can’t treat compact development as a way to solve the respiratory health problems associated with poor air quality — while concentration and emissions go down with compactness, residential exposures go up.
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