The Urban Health Desert

Air pollution. Asthma. Obesity. These are among the plights of the modern city. As the world's cities become home to a greater percentage of the population, better urban planning will be needed to reduce these negative health impacts, according to a new report from the University College London/Lancet Commission on Healthy Cities.

In some senses, we've done alright so far – sewage treatment facilities, for example, have greatly reduced water-borne disease in urban areas, and the concept of locating industrial facilities away from housing and schools has also cut down on the adverse health impacts these heavy polluters can cause in people. But as the report notes, those positive developments are not spread evenly throughout the increasingly urban world. And as cities continue to grow in both people and wealth, it's not a guarantee that these best practices will be put in place in time.

Economic growth and demographic change won't necessarily make an unhealthy city into a healthy one, argues the report. And even within cities, some areas – often the poor ones – will have worse health conditions than others. The disparity within cities can be greater than that between cities and rural areas. This, the report argues, is especially true in developing nations.

"The so-called urban advantage – a term that encapsulates the health benefits of living in urban as opposed to rural areas - has to be actively created and maintained through policy interventions," the report notes.

Like many health issues, finding solutions to urban health problems is almost as complex as the mix of factors that cause them and the differing urban scales in which they emerge. The health of people in cities is affected by a variety of urban processes – from urban form to design to infrastructure. As such, the report argues that urban planning must be a driver in the development and implementation of health-focused policies in order to reduce the factors that can create negative impacts on public health.

Maybe the most basic challenge the report stresses is that it is impossible to develop overarching plans that account for all the complex possibilities and interactions that could impact health. Instead, the authors argue that incremental approaches are necessary. A trial and error approach of implementing localized and small-scale projects will help to identify effective measures and offer starting points for scaling these ideas up. The report also emphasizes the importance of closely assessing these efforts to understand how and why things work or don't.

The report looks at case studies in sanitation and waste water management, urban mobility, building standards and indoor air quality, the urban heat island effect, and urban agriculture, and suggests that urban planners and cities should be learning from good examples at a variety of urban scales. The report points to successful community-driven sanitation projects in Mumbai slums, programs in Bogota that encourage physical activity and initiatives to cut urban heat by increasing plant and tree cover in London.

But for all these successes, there are still areas within Mumbai and Bogota and London where the populations are disproportionately affected by the lack of sewage facilities or where housing is disconnected from the public transit network or in a part of town surrounded by asphalt and concrete. Understanding how urban policies and practices can create or counteract these problems will be crucial for the development of healthy cities in the 21st century.

Written by Nate Ber@The Atlantic: Cities