People, Place and Health

Exploring the Intersection between the Built Environment and Health Behaviours

Joanna Grenon, Greg Butler and Randy Adams, all from the Centre for Health Promotion, Health Promotion and Chronic Disease Prevention Branch, Public Health Agency of Canada

New research is taking a more multidisciplinary look at the built environment to understand the complex interactions between area-level physical characteristics, social determinants of health, and health behaviours and outcomes. For example, results are showing that characteristics of the built environment may affect our risk of obesity and chronic diseases, such as heart disease and type 2 diabetes, by supporting or hindering such health behaviours as physical activity and healthy eating. This article explores these relationships and discusses how changes to the built environment may have a positive influence on health.

The Built Environment, Then and Now

Every place has a natural environment, characterized by climate and terrain. The built environment reflects how we shape these places for human habitation. The design of buildings, the location of stores, factories, offices and schools are all part of the built environment, as are the location and design of roads, sidewalks, bike lanes and footpaths.

Early communities tended to be very compact, because walking was the primary mode of transportation. Over time, new transportation technology and concerns about quality of life have led to more dispersed urban environments. Because a community is a system, changes in one of its dimensions can lead to unintended consequences in others. Currently, there is concern in the health promotion field that built environments are being constructed in ways that make health enhancing behaviours, such as physical activity and healthy food choices, increasingly difficult to pursue.

Statistics Canada data from 2005 suggest that fewer people are living in compact neighbourhoods that support walking and cycling to work. For example, from 1992 to 2005, the proportion of workers with round-trip commuting distances of under 29 minutes fell (from 27% to 21%), while the proportion of those with commuting journeys of greater than 90 minutes rose (from 17% to 25%).¹

The Built Environment and Health Behaviours

Current levels of obesity are clearly recognized as a public health issue. As individual-level factors alone have been unable to explain the rising prevalence, investigators are studying the linkages to the neighbourhood environment and have found some evidence of an association between sprawling, single use, residential neighbourhoods and higher levels of obesity.^2,3,4 Neighbourhoods populated by people with low education levels have also been found to be positively associated with higher body mass index (BMI) values for both women and men,⁴ while inverse relationships between area-level socioeconomic status and obesity/overweight have been documented for both adults⁵ and children.^6,7

Access to healthy food
The built nutrition environment includes restaurants, grocery and convenience stores, as well as the sidewalks, roads and bus routes that provide access to them. The location, number and type of such structures can vary considerably from place to place--depending on economics, zoning policies and the demographic composition of the area. Zoning policies, for example, can affect the proximity of food outlets to residential areas and whether space constrained stores are permitted to increase fruit and vegetable offerings through sidewalk displays. The physical shape of neighbourhood lots can also influence the type of buildings that are erected. For instance, smaller, oddly shaped urban lots may lend themselves to convenience stores and fast food restaurants rather than the larger supermarkets that are more typically seen in suburban areas.

Research shows that most of the food eaten in Canadian households is prepared in the home,⁹ suggesting that access to retail food resources is an important prerequisite to healthy eating. Hence, urban areas where residents have limited access to healthy food because of physical and economic barriers have become known as "food deserts."⁸ Indeed, international studies have shown that living in such resource-deprived areas is associated with poor diet.¹⁰

Food deserts are characterized by the presence of few or no supermarkets, with small/convenience stores instead. Access to public transportation is generally limited and residents who live in such areas often do so out of necessity, rather than choice. Mapping of supermarkets by neighbourhood in Edmonton and Montréal has suggested that food deserts exist in these cities.^8,11 Figure 1, for example, shows how access to supermarkets in Montréal varies with a social deprivation index measured by five neighbourhood variables: percent of the population with low income, percent of lone-parent families, unemployment rate, education level, and the percent of the population who are recent immigrants.

Figure 1 Access to Supermarkets in Montréal Census Tracts Relative to Social Deprivation Index, 2001

Note: Values in bold are higher than the average for all census tracts. Classes are sorted by mean value of social deprivation index.
Adapted with permission from: Apparicio, P., et al. (2007).⁸

Active transportation
Physical activity encompasses more than exercise and leisure-time physical activity. It also includes what is referred to as "active transportation"--activities such as walking and cycling to school, to work and/or for errands that are incorporated into the normal activities of daily living.

Research has shown that the extent to which both forms of physical activity are practised is linked to the built environment. For example, there is evidence that the density of physical activity resources in the community is associated with physical activity prevalence.¹² Research also shows that integrated communities, with a variety of destinations accessible by safe and supportive walking environments, are associated with a higher prevalence of walking to work.¹³

Lost opportunities--The loss of physical activity from active transportation is often noted in studies about the built environment. This is concerning, because walking and cycling as a means of active transportation can provide a significant portion of a person's daily dose of physical activity (30-60 minutes for adults and 90 minutes for children, as recommended by Canada's Physical Activity Guide to Healthy Active Living). A study of children in the United Kingdom found that walking to and from destinations was one of the most important sources of their daily activity. Results also showed that, among older children, the walk to and from school was responsible for more calorie expenditure than recreational games or physical education at school.¹⁴

Physical activity from walking and cycling has been shown to reduce disparities in adult physical activity levels.¹⁵ This may be due to the greater importance of walking and cycling for transport in the lives of people with lower incomes--activities that are not captured when only leisure physical activity is considered.¹⁶

Modifying the Built Environment . . .

. . . to support healthy eating
While grocery stores and restaurants are walkable destinations in many communities,¹⁷ a U.S. study found that, in some neighbourhoods, there are both real and perceived barriers to local shopping, such as the need to cross busy streets and the lack of pedestrian routes (see sidebar). Moreover, people's preferences and habits may be geared toward driving instead of walking so that they can shop at more than one location or at stores with a better selection that may be further from home.¹⁸ Locating retail food outlets close to residents may be more important in high walkability neighbourhoods, where residents can or must walk for such errands.¹⁹

Crossing the Road . . . or Not? A recent article in The Toronto Globe and Mail reported that residents of a Toronto seniors' complex were paying $4 to take a bus to the shopping mall across the street, because they couldn't cross the six-lane road in the time the traffic light took to change.22

Research in the U.K. studying the effects of introducing supermarkets to resource-deprived areas found some positive impacts on fruit and vegetable consumption.^20,21 The greatest effects were found among:

• people with poor diets (who increased fruit and vegetable consumption by 60%)
• those who had previously shopped at limited/discount stores
• and those living within 750 metres of the new store²¹

Studies point to the importance of understanding the attributes of place and tailoring the built environment to take into account its norms, composition and needs. Starting a community garden is one such application (see sidebar).

Produce from Gardens Community gardens have shown promising results in a study of Toronto neighbourhoods. Residents reported improved nutrition for themselves and their families, more opportunities for physical activity and increased social cohesion. Produce was described as fresher, more culturally appropriate and more cost effective than that in local grocery stores. However, some residents expressed concern about the quality of soil in reclaimed land and the impact of urban air pollution on the safety of the produce.23

. . . to promote physical activity
In a built environment that is increasingly dominated by the automobile, opportunities for active transportation are becoming squeezed out. At the same time, lower income Canadians (particularly seniors, adolescents and families headed by single mothers) are less likely to have access to an automobile and, hence, are more likely to be adversely affected by built environments that impede safe, active transportation.

A number of solutions need to be considered to ensure that women, men, boys and girls have better prospects for being physically active through built environments that support both active transportation and leisure-time physical activities:

• funding infrastructure that supports active transportation and its perceived safety--including bicycle parking at transit stations, shopping and work places; and well-lit and well-constructed sidewalks and bike lanes in the city, in suburbs and in rural areas
• providing recreation facilities in the workplace and/or community to permit men and women with limited opportunities for activity to exercise at lunch, or before or after work
• encouraging residential, commercial and recreational development near transit stations (often called Transit Oriented Development, or TOD), to reduce travel time and create further opportunities for integrating physical activity into daily life

Found opportunities--Changes in the built environment also offer the potential for improved safety and reduced risk of injury during active transportation. For example, making pedestrian and bike routes more visible, continuous and dominant can increase actual and perceived safety.

Summing It Up

Creating built environments that support healthy behaviours has a number of benefits for men, women, boys and girls, including improvements in population health as a result of regular physical activity and healthy eating. Both reduce the risk of chronic disease (e.g., heart disease, type 2 diabetes and some cancers), premature death and disability. Across sectors, additional benefits may be seen--such as those from an environmental perspective (e.g., reduced energy consumption, air pollution and greenhouse gas emissions) and those from a transportation perspective (e.g., reduced per capita vehicle use).

Modern zoning applications regarding the use of residential, employment and retail property have important implications for health. Consequently, there is an opportunity for various players--urban planners, transportation engineers, environmentalists, public health specialists and researchers--to work together on this area of intersecting interests to shape built environments that support healthier, happier populations living in more sustainable communities.