Diagnosing the city’s ailments

Spacing asked Toronto's Medical Officer of Health, Dr. David McKeown, to draw the connections between urban planning and public health. As it turns out, the way we design our cities can be as vital to our health and well-being as an apple a day.

Spacing: What is the link between the work that you do and the public realm?

McKeown: The city shapes our health in a number of different ways. Toronto's Board of Health has always been concerned about the urban environment. This year we're celebrating our 125th anniversary. My predecessor 100 years ago was concerned about issues such as housing and slum conditions, so there's been a long-standing connection between the built environment of the city and the health of the people who live in the city.

Spacing: What factors do you look for when you're evaluating the health of a neighbourhood?

McKeown: There are a number of health issues that are closely tied to the urban environment in which people live. One is the set of health problems associated with air pollution, and this is something we've been working on for a long time. The ways in which cities are built determine the extent to which motor vehicles are used and influence the intensity of our energy use, both of which cause air pollution. Cities that are made up of dense, complete communities that favour active transportation are healthier for a couple of reasons. Active transportation (such as walking or cycling) generates much less air pollution, but it's also healthier from the perspective of physical activity. Research we've done has shown that pollution from the use of motor vehicles in Toronto accounts for about 440 premature deaths every year, so urban environments that favour active transportation, favour people getting out of cars and onto the streets, are healthier.

Spacing: What's the biggest threat to Toron-tonians' health?

McKeown: There's no one answer to that question. If you look at what causes people to die prematurely, or be admitted to the hospital, clearly cardiovascular disease and cancer are the big killers in our society and that's true of Canada as a whole. If you look at what kills and injures people early in life — for young people, it's largely injuries — that's another aspect of health that's influenced by urban design. Take community safety, for example, and whether or not there are people around. Safe cities are cities that are full of people — remember Jane Jacobs' "eyes on the street?" The way our streets are designed can also have an impact on pedestrian injuries. Streets that are pedestrian-friendly are safer and will have fewer people in the emergency room and hospitals.

Spacing: What public health issues are you planning to investigate in the year ahead?

McKeown: One thing we'll be working on is the whole issue of climate change adaptation. The city has a climate change action plan and is now developing a climate change adaptation strategy, which will look at what we can do to minimize the impact of climate change that will occur over the next several decades — because even though we're trying to take several steps to reduce climate change, it's already starting to happen. One of the health implications that is of particular interest is the impact of extreme temperatures, particularly extreme heat. We already have a heat alert program, under which we monitor climate conditions. When the temperature rises to the point that we expect to see an increase in premature death, then we issue an alert, and certain response systems, such as the opening of cooling centres, take place. As climate change progresses, we expect the number of heat alerts issued to increase. Some of the things that will help us to adapt are in the urban planning area. You're familiar, I'm sure, with the urban heat island effect? Planning policies which try to avoid dark, hard surfaces, which promote things like green roofs, which promote an expansion of the urban forest, all of those things are helpful in reducing the heat island effect and reducing the risk for vulnerable people due to extreme heat.

Spacing: There are many groups doing advocacy work around the issues you have mentioned here. Do you find people respect your advice more because you're a doctor?

McKeown: I do think that we value health in our society, and where there is strong evidence that our health is being influenced or affected by an urban planning issue or by an environmental issue, that does get people's attention. Our engagement on public policy issues carries some weight because we bring a health perspective to the debate. But we are often working in collaboration with neighbourhood and non-governmental organizations or other health groups in pushing for healthier public policy. Many of these are complex issues and the health perspective can be very important, but it's not the only one.