The nature of urban living poses some distinctive health challenges. People are crowded together, which means that contagious diseases spread more quickly. Concentration of activities and people makes disposal of wastes and effluents a larger and more difficult task than in the countryside. The sheer scale of vehicle movements in cities also poses greater risks of accidents. In addition, there is evidence that urban living impacts on lifestyles in a negative way in health terms. Not only is urban employment likely to be less physically demanding than its rural equivalent, but access to tobacco, drugs, alcohol and unsafe sex is also greater. Urbanization is also associated with a shift towards calorie-dense diets, characterized by high levels of fat, sugar and salt.
On the other hand, urbanisation is a force that can generate economic growth to fund better health care. In a world that is rapidly urbanising, the way cities develop will have a major impact on global health for the next generations.
The challenge of the slums
Many of the negative ways that urban living impacts upon health are intensified by slum living. Overcrowding is most intense in the slums, clean water and adequate sanitation are often lacking.A WHO/UN Habitat report noted “Pneumonia and diarrhoeal diseases are the leading causes of childhood death globally, and can be a particular problem in urban settings due to crowding, indoor air pollution and poor access to health care in urban slums. For similar reasons, children in urban areas are susceptible to death from malaria and vaccine-preventable illnesses such as measles.” The WHO researchers found that in Africa, Asia and the Americas “children from the poorest urban families are roughly twice as likely to die as children from the richest urban families… In each of the 42 low- and middle-income countries for which data (from 2000 onwards) are available, the poorest urban children are twice as likely as the richest urban children to die before the age of five years.”
Aspirations and obesity
At the same time, there is a growing middle class in rapidly urbanising countries, as I have noted in previous blogs. Their aspirations are towards an urban lifestyle based on car ownership and low density suburban housing. In India there was a 38-fold increase (3 to 115 million) in the number of registered motor vehicles between 1981 and 2009. A report by UN-Habitat records that in India “built-up areas grew faster than the population in nearly all of the largest cities, especially during the 2000–11 period in Greater Mumbai, Bangalore, Pune, Jaipur, and Kolkata.” Similar urban trends can be observed in other parts of the developing world. A further piece ofresearch for the World Bank revealed that while bicycle was the most common mode of travel to work for rural dwellers, for urban residents it was a private car.The researchers found that those who used any mode of active travel to work were significantly less likely to be overweight or obese than those who travelled by private vehicle.
A role for planners
In summary, there are clear linkages between urban living and health at both ends of the wealth spectrum. Slum environments make the poor ill and kill some of their children. Threats of eviction create stress and insecurity for the millions living in informal and hence illegal settlements, not to mention the problems people face when they are actually evicted and their homes are bulldozed. Meanwhile the car-dependent lifestyles of the burgeoning suburbs are creating the problems of obesity and related diseases that have become a familiar feature of health profiles in the developed world.
The pace of urbanisation and the long-lasting nature of urban development mean that the global health maps of the future are being made today. Yet we know how to plan healthy cities. In the centenary since the RTPI was formed the practice of town planning undoubtedly contributed to the significant improvements in public health and life expectancy. The tragedy is that across so much of the developing world the statutory planning systems have failed to adapt to the challenges of rapid urbanisation and too often have become part of the problem rather than the solution. A new urban planning is needed, reconnected to its roots in public health.