The social distribution of health in an urbanised world
The global movement towards urban living has brought a number of social, economic and health benefits. Urbanisation has benefited many local economies and businesses, with urban areas being economically more prosperous than their rural counterparts due to economies of scale, pooling of talent and skills and availability of multiple services and technologies. Conditions of housing and sanitation in cities have improved markedly as has average household income, levels of education and broader opportunities for women to participate in the labour force. Throughout the twentieth and twenty-first centuries, there have been significant improvements in indicators of health and life expectancy among urban populations.
Why then a concern about urban health inequities? In all countries, rich and poor, there is an unequal social distribution of health both within countries (the urban-rural divide) and within cities (the social gradient). Even though health is, on average, better in urban than in rural areas, this masks urban disadvantage, where health can be as bad as or worse than in rural areas. A 2007 analysis of child health outcomes in 47 developing countries found that the risk of stunting and mortality was on average 1.4 times higher in urban than rural areas while, in nine of the 47 countries, urban children from lower socioeconomic households had higher rates of mortality. In sub-Saharan African cities, children living in informal settlements are more likely to die from entirely preventable respiratory and waterborne illnesses than those living in rural areas. In Kenya, for example, not only are there marked inequities in under-five mortality rates within the city of Nairobi, but the rate is far worse in Nairobi’s slums and informal settlements than in Kenya as a whole and its rural areas.
Urbanisation itself is re-shaping population health problems, particularly among the urban poor, towards non-communicable diseases and injuries. As the degree of urbanisation and national income increases, so too does the prevalence of diabetes, heart disease, obesity, mental health problems, alcohol and drug abuse and violence. In low- and middle-income countries the prevalence of hypertension is increasing, with rates being higher in urban than in rural settings. Obesity has become increasingly more prevalent among socially disadvantaged groups and often sits cheek-by-jowl with underweight among poor populations in many cities throughout the world.
Within poor countries, poor people suffer a higher burden of morbidity and mortality from traffic injuries. In rich countries, children from poor socioeconomic classes suffer more injuries and deaths from road crashes than their counterparts from high-income groups. Crime and violence are more pronounced in urban areas, especially in slums, than in rural settings. Homicide rates are high and still growing in some cities, and robbery poses a major problem in many urban centres, not least because it contributes to general feelings of fear and insecurity.
The social and environmental determinants of urban health inequities
The Global Research Network on Urban Health Equity (GRNUHE) followed a ‘social determinants’ approach to health, exemplified by the World Health Organization’s Commission on Social Determinants of Health, headed by Professor Sir Michael Marmot. This approach notes that health is a result not only of biology but also of the interconnected material, psychosocial and political conditions in which people are born, grow, live, work and age. Following a social determinants approach has implications for the policies and programmes aimed to reduce these inequities. Under this approach, urban health equity depends vitally on pursuing processes of political empowerment so that individuals and groups can better represent their needs and interests and, in so doing, can challenge and change the unfair distribution of material and psychosocial resources.
In urban terms, the social determinants approach suggests that improving living conditions in such areas as income, housing, transport, employment, education, social support and health services is central to improving the health of urban populations. In reality, however, the restructuring of cities by the global marketplace, while conferring benefit for some, has led to rapid and often unplanned urbanisation, outpacing the ability of governments to build essential infrastructure and services and provide basic needs for living. While urban areas pose a major opportunity to improve health equity, to date current urban restructuring has contributed to a growing gap between the living conditions of rich and poor in cities.
While city populations have tended to become wealthier than their rural counterparts, they have become increasingly unequal. For the majority of developing countries in Africa, Asia and Latin America, inequalities in urban areas generally exceed the inequalities in rural areas (Figure 2). These relative inequalities in social matters affect the social distribution of health outcomes. Work by Richard Wilkinson and Kate Pickett, The Spirit Level: Why Equality is Better for Everyone (2009), although based on data from high-income countries and not at the city level, demonstrates a marked correlation between income inequality and health inequities within nations.
In addition to the social causes of urban health inequities is global environmental change. There is now widespread recognition that the disruption and depletion of natural environmental systems, including climate change, has profound implications for the health of people globally. These environmental disruptions encompass climate and atmospheric change, pollution and ecotoxicity, depletion of resources and loss of habitats, species and bidoversity. The combination of these changes is already affecting the health of the population in some parts of the world and, as these trends continue, the number of people affected will grow.
A ‘social and environmental determinants’ model of urban health equity
During 2009 and 2010, GRNUHE, which was financially supported by the Rockefeller Foundation, reviewed the evidence on what could be done to address the social determinants of material, psychosocial and political empowerment of urban populations, especially in low- and middle-income countries, and thereby improve health of the urban poor and the socio-economic gradient in urban health. They developed a model that focused on the interplay between the urban physical form, its social conditions and infrastructure, the added pressure of climate change and the role of governance to determine maximum and equitable health benefits from urbanisation.
They found that there is a reciprocal relationship between urban social conditions and the built environment. For example, poorly planned cities and suburbs coupled with inefficient public transit and road systems result in long and expensive commutes for low-income workers. Long commutes can fray family and community ties, reduce the opportunity for social gatherings or leisure and recreation, create conditions that make crime and violence (and the fear that accompanies them) more likely or reduce access to basic amenities and services. They also note that urban planning can either contribute to or help mitigate climate change, depending upon how energy-efficient and carbon-intensive the city’s built form and transportation systems are. The nature of the physical environment can also make it easier or more difficult for people and communities to adapt to climate change. Similarly, the effects of climate change and other forms of environmental degradation can exacerbate health inequities that are rooted in social and economic conditions, because people who are more socially disadvantaged are more likely to live in hazardous areas and have less access to adaptive technologies such as air conditioning, for example.
When these aspects of urban life – the natural and built environments and social and economic conditions – are well integrated, the product is both improved health and greater health equity and, even more broadly, higher and more equitable levels of human development. This is to the benefit of urban citizens, their communities, local businesses and large employers, the city and indeed the nation as a whole.
This is a simple message, but one not yet established in cities around the world. A social and environmental determinants approach implies that much of the policy and practice that affects urban health equity lies outside the health sector. In addition to health ministers, national and city ministers for planning, housing, transportation and the environment have a crucial role to play. Effectively communicating the potential for all sectors to impact on urban health and health equity is crucial in order to incorporate health impacts into urban governance.
All three of the interacting aspects of urban life in the centre of our model are, in turn, nested within the broader concept of urban governance. ‘Good’ – or, in our case, ‘healthy’ – urban governance is concerned with the equitable distribution of power and resources, and with ensuring an appropriate balance among the competing demands of the various stakeholders in the city for the health of all. This requires a form of governance that engages and empowers the citizenry, especially the most disadvantaged and least powerful people and communities. As environmental sustainability is becoming embedded in national and city governance, so too must health if we are to reduce urban health inequity. That urban health inequities and inequities in social and environmental determinants exist and appear to be widening, particularly in cities in low- and middle-income countries, suggests that there remains much to be done to secure greater health benefits from the opportunities of urbanisation around the world.
This work was made possible through funding provided by the Rockefeller Foundation and undertaken as a contribution to the Global Research Network on Urban Health Equity. The views presented herein are those of the author and do not necessarily reflect the decision, policy or views of her institution.