Chapter 4: The Chief Public Health Officer's report on the state of public health in Canada 2008 – Environment and housing

Social and Economic Factors that Influence Our Health and Contribute to Health Inequalities

Environment and housing

Where a person lives matters since both natural and built environments influence health. It creates the context for determinants of health such as income, employment, social networks and personal behaviours.

Physical environment

Although health related to the environment is primarily outside the scope of this report, the physical environment can also contribute to health inequalities (e.g. adequacy of housing, indoor air quality and water supply). Environmental challenges associated with changing conditions, particularly climate, are expected to place increased health burdens on society and the infrastructure now and towards the foreseeable future.

Outdoor air pollution causes health effects that include coughing, aggravation of asthma and other respiratory diseases, as well as the exacerbation of cardiovascular disease. This results in increases in emergency room visits, hospital admissions and premature death as air quality degrades. Research indicates even low concentrations of these pollutants can result in adverse health effects.²⁵¹ An increase in air pollutants contributes to an increase in morbidity and premature mortality. Health Canada estimates that, in eight Canadian cities, air pollution is responsible for 5,900 excess deaths per year.²⁵²

Particulate matter and ozone are two key components of smog. In southern Ontario and southern Quebec, an indicator of exposure to ground-level ozone concentration has increased by about 17% and 15% respectively between 1990 and 2005, while there has been no discernible change in the indicator for particulate matter over the same time period. No trends were discernible for either pollutant in other parts of the country.²⁵¹

For the majority of Canadians, water quality is considered to be safe, with 85% of Canadians receiving their water supply from treated municipal water works.²⁵³ Nevertheless, there are still challenges to be addressed, particularly in small and remote communities and on First Nations reserves.²⁵⁴

Built environment

The majority of Canadians (80%) live in urban areas.¹³³ These built environments can influence physical and mental health through factors such as community design, adequate housing, access to safe water, good sanitation, safe neighbourhoods, and adequate access to education, recreational services, public transit and child care.^{7, 167, 261} In essence, the built structure provides the setting for many of the social determinants of health.²¹⁶

In Canada, the built environment is undergoing significant change and one of the greatest challenges is urban sprawl. Urban growth now typically includes the creation of low-density, decentralized communities that include suburban residential, strip retail and employment development.

While city centres (cores or central business districts) have traditionally provided the greatest source of employment, reliance on suburban employment has now grown as the growth of cities has increased outward. For example, although, the number of jobs in Canada’s city centres has increased, the number of jobs in Canada’s suburbs has increased four times as much.258 Decentralized residential and employment areas have also led to the development of extensive road networks and greater reliance on vehicle commuting. The number of Canadians who drive to work increases with distance away from the city centre: at 5 kilometres from the centre, 58% of the population drive; and at 20 kilometres away, 80% drive.259 This increase in vehicle use and commuting has resulted in higher incidences of vehicular injury in suburban areas, as well as higher rates of heart and respiratory diseases and obesity, and elevated stress related to both commuting among congested traffic and increased noise levels.260, 261

Urban land uses can positively and negatively influence health behaviours. For example, ‘walkability’ measures the extent to which an urban environment supports residents moving between places using an active, safe and more environmentally friendly form of transit such as walking or biking. However, walkability is dependent on whether the community design includes recreational pathways and sidewalks, safe levels of lighting, and compatible land uses that ensure pleasant safe spaces for both recreational and transit activities.²⁶¹ In more ‘walkable’ neighbourhoods, people tend to have increased physical activity levels which may lead to lower rates of obesity.²⁶² Similarly, the built environment can influence access to affordable and nutritious foods. There is evidence that compared to higher-income neighbourhoods, low-income neighbourhoods often have limited grocery stores (particularly those selling fresh produce), offer nutritious foods at a higher cost and have a greater concentration of fast food services – all of which may contribute to poorer eating habits among residents.

The built environment can also provide opportunities for social interaction through an array of social networks and organizations. Generally, the larger the urban centre, the greater the number and complexity of social networks. Social engagement in the community builds trust, efficacy and a sense of belonging that is associated with improved mental and immunological health.¹¹⁷ Urban centres tend to be less culturally and socially homogeneous and have diverse populations. Within these cities, communities comprised of close networks of people of similar cultural and social perspectives offer the benefits of community such as social support.²⁶⁵ Research has shown, for example, that recent immigrants can better integrate into Canadian cities that have communities with strong social and cultural support networks.²⁶⁶

Although urban areas provide many opportunities for social contact with others, they can also create anonymity and isolation.²⁶⁵ Regardless of neighbourhood density, many urban dwellers say that they do not know their neighbours, a number of elderly residents live alone, and those who are not connected with the greater community can experience isolation.^{265, 267}

Housing

Housing, or lack thereof, is a critical component of an individual’s environment. In Canada, 13.7% of Canadians report being unable to access acceptable housing. The term acceptable housing used here refers to housing that is affordable (costing less than 30% of before-tax income), does not require major repairs and is not overcrowded.²⁷³ The Canada Mortgage and Housing Corporation reports that ‘affordability’ is the least frequently met of these criteria for acceptability.²⁷⁴

Health outcomes related to housing are complex, as housing can directly and indirectly impact health. Inadequate housing may produce direct effects in extreme climates. Respiratory disease/poor lung function and allergies related to moulds from cold, damp or poorly ventilated houses may develop.²⁷⁸ Other health conditions can arise related to exposure to specific toxic substances like lead and asbestos from substandard plumbing and insulation, environmental tobacco smoke and residential radon from contaminated soil.²⁷⁹

Overcrowding and poorly ventilated houses can also increase susceptibility to disease. The number of people per dwelling has been known to greatly impact the physical and mental health of inhabitants, including raising the risk of acquiring tuberculosis.²⁷⁸ This is especially true for many Canadian Aboriginal populations and for immigrants from some countries where older generations infected with tuberculosis in childhood may experience disease reactivation later in life that can infect others in the home.²⁸⁰ Both groups experience a higher rate of overcrowding than the general population and also account for the highest rates of new and relapsed cases of tuberculosis in Canada.^{209, 281} Among Aboriginal populations in 2006, rates of new and relapsed cases of tuberculosis were at 27.4 per 100,000 compared to only 5 per 100,000 in the overall population. Among immigrants, rates of new and relapsed tuberculosis cases were 14.8 per 100,000.²⁰⁹

Homelessness is also a health issue. It is difficult to measure how many people in Canada are homeless as homelessness is a continuum with a variety of short and long term experiences.²⁸² The most recent number often cited – 150,000 people – is believed to be an underestimate.²⁸³ Some of these people become homeless as a result of inadequate income, living in a community with inadequate housing, or having a mental illness, which may hinder opportunities for employment and income.²⁸⁴ While homelessness can affect a broad range of people, approximately one third of the homeless are between the ages of 16 and 24 years.²⁸⁵ A third of street youth report trading sex for shelter, money and substances, particularly cigarettes (80% of street youth smoke daily) and have higher rates of STIs and blood-borne infections than youth in the general population. A lack of housing contributes to a vicious circle influencing eligibility for income supports, community benefits, voter registration and employment options that could bring about changes in living conditions. As well, about half of youth living on the street have been involved with the child welfare system at some point during their lifetime. An equal share were abused as children and left home as a result. Many street youth dropped out or were expelled from school. In 2003, for both male and female street youth, the main source of income was social welfare.²⁸⁶