Whether seeking new social connections, pursuing opportunities for jobs and education, or escaping a war zone, health and well-being are central to why people move from one place to settle in another. And when people move, they tend to gravitate toward big cities.
In fact, over 54% of the world’s population today lives in urban areas, a proportion that is expected to increase to 66% by 2050, according to the UN report “World Urbanization Prospects”.
Cities attract people because they provide important “opportunity spaces” where people can expand their contacts and chase better economic status or personal dreams, said Franz Gatzweiler at the IAP for Health Conference in Beijing, China on 28 September. But not every city is built to sustain these spaces for its people. And the result is a big health impact that scientists and policymakers can’t afford to ignore.
Gatzweiler is the executive director of the global programme “Urban Health and Well-Being: a Systems Approach” at the Chinese Academy of Sciences Institute of Urban Environment in Xiamen, China. The programme is sponsored by the International Council for Science (ICSU), the United Nations University, and IAP for Health. His talk was a highlight of the IAP for Health conference, where global leaders in healthcare and medicine met to discuss new and better ways to promote good health and well-being for a growing global population.
Understanding the role cities play is indispensible to the future health of urban populations. They provide a habitat, goods and services, structure in the form of rules and regulations, and cultural spaces – which in turn encourage innovation and ideas. But understanding the complexity and uniqueness of health problems in urban environments is beyond the scope of any one discipline. So Gatzweiler’s programme advocates for a “systems approach” that he says breathes life into the unused potential found in cities.
“The multi-dimensional spaces provided by the urban environment – or the systems in which people can thrive – have not been fully explored and made use of for human health and well-being,” he said. “The systems approach is a key to unlock these potentials of cities for human health and well-being.”
For example, one kind of unused potential occurs when infrastructure and social support are not available for a rapidly growing population. It’s called “dead capital” – assets such as slums or polluted industrial areas, which can’t be easily bought or sold. From a human perspective, dead capital also amounts to a space where people can’t fully develop their potential. They create illness and trap people in poverty.
When a rapid increase in population density outpaces the development of infrastructure, that dead capital becomes pervasive. Only a serious investment in infrastructure focused on improving people’s well-being can bring it back to life.
“What matters today,” he said, “is that although health has improved and is better than ever before, especially in cities, today’s symptoms of deteriorating urban health are again signs of failing to apply interconnected thinking, collective intelligence and action for urban health and well-being.”
But dead capital is just one major piece of an overwhelmingly complex puzzle. Gatzweiler said that part of the systems approach is that it provides a new perspective on the process of knowledge creation itself. It manages the complexity by seeking a diversity of many kinds of information rather than over-focusing on one form of useful data at the exclusion of others, and accepting that there will be unfillable gaps in that data.
“But the core of the concept is that after acquiring knowledge and understanding of how health in cities is improving or deteriorating, it requires societal engagement to address health issues in cities and to bring them to the attention of the public,” he adds. “Cities are not only complex, they are also self-organizing systems. As such, they are uncontrollable or unplannable by one central entity alone.”
People, he said, are part of the health problems they define to be relevant. And that makes the systems approach much more challenging. “It requires a society which is educated, aware and empowered – given the rights – to address issues of urban health.”
Cities also bring with them a set of their own specific health problems that need managing. The stress of urban life also weighs on the human mind’s abilities to manage emotions, causing more mental health problems. For example, one study published in Nature has shown that in stressed city-dwellers, a brain region called the amygdala involved in processing threats and fear was more active.
The risk of developing schizophrenia or depression is also higher in cities. “Our brains are not well-adapted for life in our urban environments,” Gatzweiler says.
But there are ways to curb the effects on city living on mental health. Researchers have begun to track the link between the availability of green spaces – such as parks – and better mental health. And now some urban policymakers have started to take notice of the importance of giving citydwellers' brains the space needed to relax. For example, the United Kingdom highlighted the 2011 restoration of Clissold Park in northeast London as an example of a health intervention.
To some degree, the problems are economic. As people receive more access to wealth and easily available food, their obesity rises too – and a four-decade analysis published in The Lancet projects that 20% of the world's population will be obese by 2025. Meanwhile, those with low incomes more commonly have to suffer through poor-quality health care.
The space constraints found in urban areas can cause declines in health, as environments deteriorate and become more polluted. Air pollution increases to cause deadly cases of lung cancer – urban air pollution is linked to up to 1 million premature deaths each year, and death from lung cancer in China happens at a higher rate in cities than in rural areas, even though a lower percentage of city dwellers are smokers.
In fact, these issues are particularly relevant to China, as the story of China’s rapid and strong development is a story of urban growth. The percentage of Chinese people living in cities grew from 18% in 1978 to over 50% in 2011, Gatzweiler noted. And current projections estimate that 1 billion Chinese people will live in cities by 2040, an increase of 400 million over the next 30 years. Twenty million migrant workers also arrive in China each year.
Now, China is already home to some of the most populous cities in the world – such as Shanghai, Beijing, Tianjin and Guangzhou. It is also seeing the development of megacity clusters – large cities that begin to encroach on each other – all of which suffer from the country’s notorious air pollution. These cities are seeing adverse health issues unfold first hand.
So China needs a new style of urbanization, Gatzweiler says, that is oriented around people and their well-being.
“A healthy city is one that is continually creating and improving those physical and social environments,” Gatzweiler said, quoting Trevor Hancock, a founder of the World Health Organization's Healthy City project. He added that healty cities expand community resources "which enable people to mutually support each other in performing all the functions of life and in developing to their maximum potential.”
Sean Treacy