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.