The Road to Equity
How the built environments in low-income neighbourhoods in Montréal are harmful to health
By Miriam Gladstone
Ninety glowing green happy faces light up the screen. Underneath, the ten miniature red frowns alert me that the patient sitting in front of me has a 10% risk of having a cardiovascular event – such as a heart attack, stroke or heart failure - within the next 10 years. This tool, named the Framingham Risk Calculator, calculates risk of cardiovascular events using a variety of individual factors, such as smoking status, total cholesterol, and gender. It is widely utilized by clinicians to help patients identify and target their modifiable risk factors for cardiovascular disease. Although the Framingham Risk Score was created based on data from a large observational cohort study and has been widely verified, it fails to acknowledge one significant risk factors for cardiovascular disease – poverty.
Cardiovascular disease is the second most common cause of death in Montréal (1), and the risk of heart disease and stroke varies across regions in Canada such that regions with lower average income have significantly higher rates (2). Interpreting these statistics begs the questions – what factors are contributing to this inequity and to what extent can an individual in a low-income neighbourhood “modify” their risk factors? A large percentage of increased health risk can be attributed to characteristics, such as smoking or obesity, that may be more prevalent in these communities. However, a complex interplay exists between individuals and the built environment in which they live which influences not only inequities in cardiovascular health, but overall in wellbeing (3).
To begin with, exposure to air pollution is a recognized risk factor that increases cardiovascular disease and is becoming more important with the progression of climate change (4). Although every individual living within a large city is exposed to pollution, neighbourhoods in Montréal with a higher proportion of low-income individuals or visible minorities have been found to contain higher concentrations of pollutants, such as nitrogen dioxide, carbon monoxide and particulate matter 2.5 (5,6). Specifically, Montréal’s central neighbourhoods which have a closer proximity to major highways have higher air pollution (5). Families who are disadvantaged may not have the financial means to move to a different house with cleaner air, or to ‘escape the city’ to a rural chalet, thus exposing them and their family continuously to pollution and a heightened risk of cardiovascular disease.
Furthermore, low-income individuals may be more frequently found to live in urban heat islands. Urban heat islands are areas of a city that are significantly warmer than surrounding areas due to a of a lack of green space and a high prevalence of surfaces that retain heat, such as pavement and buildings. Living in an urban heat island has been found to be associated with increased cardiovascular disease mortality, especially in households without access to air conditioning (7). Neighbourhoods in Montréal which had a higher proportions of low-income individuals and visible minorities are more likely to have fewer public vegetation spaces, which are essential for mitigating heat islands (8). Living in impoverished communities may increase risk of cardiovascular events due to higher exposure to heat deserts.
Finally, proximity to major roads likely impacts the health of low-income populations. Neighbourhoods in Montréal with a below average income are more likely to be found near to major roads and have higher exposure to high traffic than high income neighbourhoods (5,9). Living close to major roads subjects these populations to noise levels over 65 decibels A, which is associated with loss of sleep, cognitive difficulties in children, hypertension, development of heart disease, and hearing loss (10). Not only does proximity to major roads lead to noise pollution, but the neighbourhood’s built environment may also be prohibitive to performing physical activity. Children and adults living poor neighbourhoods in Montréal have been found to have greater risk of pedestrian and cycling injuries (9). In fact, intersections in the poorest areas in Montréal had on average 6 times more pedestrian injuries than those in the wealthiest census tract (9). Increasing physical activity is an essential and often recommended intervention for individuals at risk of cardiovascular disease. However, walking, running and biking may be life-threatening if the built environment is not conducive to these activities. Without safe places to exercise, individuals may be more prone to obesity, diabetes, and cardiovascular disease.
In conclusion, inequities in disease in Montréal exist, likely in part, not only due to individual choices, but also secondary to the built environments and city policies which are detrimental to the health for low-income communities. Physicians often counsel their patient to quit smoking, which is indeed an important risk factor for cardiovascular disease. However, modifying their patient’s daily exposure to pollutants and heat deserts requires more than individual choices. It requires advocacy for urgent creation of safer housing and green spaces within low-income communities. Similarly, although physical activity is an essential component of cardiovascular fitness, without creating walkable neighbourhoods in marginalized areas, inadequate infrastructure for physical activity puts individuals at high risk of collisions should they attempt to walk or bike. Inevitably, positive changes to these built environments will also promote and encourage individuals to make other healthier choices, thus improving the physical and mental health of low-income communities in intangible ways. Politicians must not only prioritize building safe communities that empower and encourage individual actions, but also create social policies that mitigate poverty in Montréal in order to decrease risk of cardiovascular disease in low-income populations and begin to equalize inequities. In sum, keeping these upstream determinants of health in mind when addressing cardiovascular health will help physicians to not only prevent disease, but truly heal communities.
Works Cited
1. Institut de la statistique du Québec. Causes de décès (liste abrégée) selon le sexe, Québec, 2000-2021 (in French only) [Internet]. 2022 Apr. Available from: https://statistique.quebec.ca/en/document/causes-of-death/tableau/causes-of-death-abridged-list-deaths-by-cause-and-sex#tri_es=10778&tri_sexe=1
2. Dai H, Tang B, Younis A, Kong JD, Zhong W, Bragazzi NL. Regional and socioeconomic disparities in cardiovascular disease in Canada during 2005–2016: evidence from repeated nationwide cross-sectional surveys. BMJ Glob Health. 2021 Nov 30;6(11):e006809.
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