This is the urban century. At some point over the last year or so, the United Nations Population Division estimated, the world crossed a threshold: more than half of its population lives in cities. By 2050, some forecasts suggest, 70% of the world’s population will live in cities, some of those enormous metropoles with dozens of millions of inhabitants.
The face of urbanization is vastly more diverse than what is regularly portrayed. Some of the remotest places on Earth are also the most urbanized: parts of Tarawa Teinainano (South Tarawa, the capital of the Pacific island nation of Kiribati) have a population density of 10,200 people per square km – this puts them third in the world, after Macau and Monaco, but before Singapore (7,797 people per square km).
Some of the most sparsely populated countries on Earth are also home to some of the most densely populated places. Australia (3.17 people per square km overall, putting us at number 233 in the global ranking) is building a Sydney precinct called Green Square with a projected density of 22,000 people per square km– that’s ahead of Macau.
Places urbanize because they offer opportunities – for jobs, excitement, beauty, education, greater partner choice, and for some the chance to disappear in anonymity. These are potentially healthful choices. The urban space offers better health care to those that need it; however, cities are also the environments that create many of the conditions that make people require extensive high-tech care and cure. In fact, since the beginning of the modern urbanization trend, induced by the 19th century industrialization, health problems were a mainstream concern and pathogenicity was associated with urban areas.
It is no surprise that the emergence of the modern city has coincided with the development and growth of the science and art of public health. The cholera epidemic in the City of London in the first half of the 19th century compelled John Snow to deploy a world first version of a geographic information system and start the first public health revolution.
Public health and urban health have evolved considerably. In their different iterations they have espoused a great diversity of priorities – from good sanitation (sewerage systems), access to green spaces (Mont Royal, Central Park), and transportation systems to distributed healthcare facilities.
Most of these urban public health perspectives have drawn on technocratic, often engineering, insights. For public health, the legacy has become an incredible body of increasingly complex epidemiological analyses. Many journals of urban health fill their pages with classical number crunching.
The numbers are testament to the enormous challenges in urban health in the 21st century. Even healthful behaviours like cycling can do harm in the wrong urban context. Cycling through smog, it is reported, causes vastly more damage than the health gains through exercise.
But numbers are not solutions.
In the mid-1980s the World Health Organization started its global Healthy Cities programme. In a foundation document Len Duhl and Trevor Hancock listed eleven qualities those Healthy Cities should strive to attain – indeed, the solutions:
- A clean, safe, high quality physical environment (including housing quality)
- An ecosystem which is stable now and sustainable in the long term
- A strong, mutually supportive and non-exploitative community
- A high degree of public participation in and control over the decisions affecting one’s life, health and well-being
- The meeting of basic needs (food, water, shelter, income, safety, work) for all the city’s people
- Access to a wide variety of experiences and resources with the possibility of multiple contacts, interaction and communication
- A diverse, vital and innovative city economy
- Encouragement of connectedness with the past, with the cultural and biological heritage and with other groups and individuals
- A city form that is compatible with and enhances the above parameters and behavior
- An optimum level of appropriate public health and sick care services accessible to all
- High health status (both high positive health status and low disease status)
The focus of Healthy Cities is on establishing healthy processes to attain those ambitions. Quantitative (epidemiological) research is required, but crafting those processes depends on strong sets of values among communities, advocates, social movements, politicians, and indeed – academics.
Thirty years on, and well into the Urban Century, we compiled a book that documents the hundreds of successes to date, the vision for Healthy Cities that endures, and the challenges that are ahead of us. Most of all we find that a good city for health is driven by this strong set of values like equity, participation, democracy, transparency and sustainability.
Healthy Cities are not shaped by epidemiology. They are shaped by humanity.