Cul-de-sac communities can be bad for your health.
Icons of suburban development and land-use since World War II, these communities contribute to higher rates of air pollution and obesity than neighborhoods with well-connected street grids, according to a recent Harvard Business Review report.
The article cited a study (PDF format, 332 kb) of King County, Wash. conducted by Lawrence Frank, Bombardier Chair in Sustainable Transportation at the University of British Columbia, that found a 26 percent reduction in vehicle miles per day for those who live in high-density areas.
Lower emission levels of volatile organic compounds (VOCs) and oxides of nitrogen (NOx) were found in dense residential areas with high street intersection density and mixed residential/commercial layouts.
VOCs and NOx can combine to form ozone, which has been linked to respiratory illness.
The researchers found a 21 percent decrease in NOx per person per day between the highest street-intersection density neighborhoods and the lowest.
There is about a 24 percent lower carbon dioxide emission rate per capita in King County areas with optimal land-use versus those rated with the worst.
The climate-changing gases have been linked to lower fresh water levels from Cascades Range snowpack, and may affect future salmon populations in the area.
But increased time spent in a vehicle also means less time to walk or exercise.
A second report (PDF format 16.3 mb) by Frank and his colleagues focused on Atlanta.
It found that “every additional hour spent in a car each day translated into a six percent greater chance of being obese.” The data was obtained from a survey of about 18,000 individuals.
The Atlanta study also showed a five percent decrease in the chances of being obese for each additional kilometer walked everyday, whether by choice or as a part of routine.
Residents in Atlanta were 2.4 times more likely to get the recommended level of daily activity to maintain health in highly “walkable” areas, according to the report.
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