Photo: Urban planning is a health issue

The built environment's impact on physical activity has great significance for health (Credit: caribb via Flickr).

By Dr. David L. Mowat

The origins of public health care lie far back in history, but organized public health care as we know it was born in the mid-19th century, when the Industrial Revolution caused migration to cities, overcrowding and epidemics. The Sanitary Movement introduced safe water and proper waste disposal. Later, zoning was introduced to protect people from the toxins that industrial production produced.

Today, chronic disease is a major cause of death, and much of it is the result of obesity. Throughout the developed world, more people are overweight or obese than ever before, including close to half of Canadians. This increases risks for many illnesses, including cardiovascular disease. Most troubling is the increase in the prevalence of diabetes. Nearly 7.6 per cent of Canadians have this disorder. Concerns about these preventable illnesses have led to increasing interest in influencing the built environment to reduce the burden of ill health due to chronic diseases. This also marks a return to public health care's urban roots.

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Suburban sprawl

The built environment in North America is increasingly characterized by sprawling, car-dependent suburban living. People work far from their homes, children are bused or driven to school, cars are used to run most errands and opportunities for social interaction are limited. The consequences include poor air quality, deficient social capital and an increased incidence of injuries. Heat-absorbent asphalt and concrete surfaces and a lack of tree cover can also cause higher temperatures, which can increase health risks, especially for the elderly. The built environment's impact on physical activity, however, has the most significance for health.

Environments to support walking

A growing body of evidence links the built environment to health outcomes (pdf). The evidence points to the relationship between neighbourhood design and the extent to which neighbourhoods support walking ("walkability") with health outcomes. For example, work in Toronto shows that low-density suburbs have low walkability and a higher prevalence of diabetes. Low-density suburbs also typically have a larger environmental footprint.

When we think about physical activity, recreation often comes to mind. But getting from A to B — utilitarian physical activity — has a greater potential impact on health than recreational physical activity. Supporting this type of activity requires a fundamental change in the built environment.

We know what a healthy built environment looks like. It includes a range of services — such as transit, shops, parks and community facilities — that can be reached on foot or by bike within 10 minutes. Some employment will be available within easy travelling distance. The streets are set out in a rectilinear, connected pattern rather than crescents and cul-de-sacs. Roads are relatively narrow and houses and shops are close to the street, with parking at the rear. There is a mix of housing types (fewer single detached, more townhouses and apartments above retail). These characteristics are associated with the "New Urbanism" movement. All of this requires densities to be considerably higher than those that currently prevail in our suburbs.

Getting there

Urban planners have, over many years, developed a vision of a high-quality built environment. It includes the elements that research has shown to be related to good health. However, public health and planning professionals have only recently come together to further this vision. One critical need is for evidence-based, objective tools and policies that can guide developers in designing health-supporting communities and assist planners in assessing plans. Healthy Canada by Design is an initiative involving public health departments in major cities, the Canadian Institute of Planners, the Heart and Stroke Foundation and others to provide such practical assistance.

This work is complex and involves many interests. For example, the design of roads is influenced by transportation engineers. Adding bike lanes and bus lanes may widen roads unless lane widths are adjusted. School boards may build one large school instead of several neighbourhood schools, or may not provide bike racks. This affects the level of activity required to travel to and from school.

Concerted action

A built environment that supports health is no different than a built environment that is aesthetically pleasing, that provides good recreational opportunities, that is environmentally sustainable, that minimizes the costs of infrastructure and that enhances economic prosperity by reducing traffic congestion. We all have much to gain by working together to produce better places to live, work and play.

Dr. David MowatDr. Mowat is the Medical Officer of Health for the Region of Peel, Ontario. He chairs the Built Environment Working Group of the Urban Public Health Network (representing medical officers of health of Canada's eighteen largest cities).

May 24, 2011

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