Elevated air pollution could diminish health benefits of living in walkable communities: study

25/06/2019

Researchers suggest healthy active lifestyles could be maintained with policies to limit traffic-related pollution

The benefits of living in a walkable neighbourhood could be diminished by increased exposure to traffic-related air pollution, suggests a study led by St. Michael’s Hospital and ICES, a non-profit research institute that uses population-based health information to produce knowledge on a broad range of healthcare issues.

The research, published today in Environment International, and based on nearly 2.5 million adults from 15 Ontario municipalities, challenges the notion that living in walkable neighbourhoods always improves the overall health and well-being of Canadians.

Walkability reflects how well neighborhoods afford opportunities for individuals to walk while performing daily tasks like grocery shopping, running errands, or commuting to work.

“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 research team found that living in unwalkable neighbourhoods was associated with a higher likelihood of having diabetes or hypertension than living in the most walkable communities. But, any observed benefit for those living in walkable areas appeared to decrease — or in some cases, disappear — as the level of air pollution increased.

“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 PhD graduate in the St. Michael’s Li Ka Shing Knowledge Institute and co-lead of the research. “So they may be more exposed to air pollution based simply on the amount of time they spend outside.”

The researchers said these results suggest that policies aimed at encouraging the development of walkable neighbourhoods should consider strategies to mitigate 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.

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.

ICES is an independent, non-profit research institute that uses population-based health information to produce knowledge on a broad range of healthcare issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting healthcare needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy. In October 2018, the institute formerly known as the Institute for Clinical Evaluative Sciences formally adopted the initialism ICES as its official name. For the latest ICES news, follow us on Twitter: @ICESOntario

St. Michael’s Hospital provides compassionate care to all who enter its doors. The hospital also provides outstanding medical education to future healthcare professionals in 29 academic disciplines. Critical care and trauma, heart disease, neurosurgery, diabetes, cancer care, care of the homeless and global health are among the hospital’s recognized areas of expertise. Through the Keenan Research Centre and the Li Ka Shing International Healthcare Education Centre, which make up the Li Ka Shing Knowledge Institute, research and education at St. Michael's Hospital are recognized and make an impact around the world. Founded in 1892, the hospital is fully affiliated with the University of Toronto.

St. Michael's Hospital with Providence Healthcare and St. Joseph's Health Centre now operate under one corporate entity as of August 1, 2017. United, the three organizations serve patients, residents and clients across the full spectrum of care, spanning primary care, secondary community care, tertiary and quaternary care services to post-acute through rehabilitation, palliative care and long-term care, while investing in world-class research and education.