Increased exposure to traffic-related air pollution may reduce the benefits of living in a walkable community, according to a new Canadian study published in the journal Environment International.
Walkability reflects how well neighborhoods offer opportunities for individuals to walk while performing daily tasks like grocery shopping, running errands, or commuting to work.
The study, led by St. Michael’s Hospital in Toronto and the Institute for Clinical Evaluative Sciences (ICES), a non-profit research institute, was based on nearly 2.5 million adults from 15 Ontario municipalities.
The findings challenge the notion that living in walkable neighborhoods always improves the overall health and well-being of Canadians.
“Previous research has shown that individuals living in more walkable neighborhoods are more physically active, with downstream health benefits like lower rates of overweight and obesity, hypertension and diabetes,” said study co-lead Dr. Gillian Booth, a scientist at St. Michael’s Hospital’s MAP Centre for Urban Health Solutions and ICES.
“But our findings confirm that walkability and air pollution are highly intertwined, potentially diminishing any health benefits derived from living in walkable, urban communities.”
The findings show that people living in unwalkable neighborhoods are at greater risk of diabetes or hypertension than those living in the most walkable communities. However, any observed benefit for those living in walkable areas appears to decrease — or in some cases, disappear — as the level of air pollution increases.
“Individuals living in highly walkable neighbourhoods tend to be more likely to choose active forms of transportation, like walking or bicycling, as an alternative to driving,” said Nicholas Howell, a recent Ph.D. graduate in the St. Michael’s Li Ka Shing Knowledge Institute and co-leader of the research. “So they may be more exposed to air pollution based simply on the amount of time they spend outside.”
The researchers say these findings suggest that policies aimed at encouraging the development of walkable neighborhoods should consider strategies to reduce residents’ exposure to air pollution.
“Initiatives to create walkable communities while decreasing sources of car pollution may have promise to reap even greater health benefits and have stronger impact on the health of Canadians,” said Howell.
Previous research has also linked air pollution exposure to a range of cognitive issues, including memory problems and dementia.
Researchers used participant data from the Cardiovascular Health in Ambulatory Care Research Team (CANHEART) cohort, a population-based cohort drawn from databases including nearly all adults living in Ontario.
Source: St. Michael’s Hospital