Urban health and well-being

From their earliest beginnings, cities have brought both benefits and risks to the health of their inhabitants. Although some of the hazards have been banished, others remain — and new ones have emerged. By Stephanie Pain

Transporting people around the cities of the future is a public-policy challenge, but it's also an opportunity to improve the health of urban populations.

Water is a necessity for any city, but too much of it can threaten lives and infrastructure. As climate change looms, new approaches can help to turn a threat into a resource.

Exposure to nature makes people happy and could cut mental-health inequalities between the rich and poor.

Deprivation leads to stress, and stress to bad health. A park, and the science behind it, aims to break that chain.

Pollution poses a significant challenge to food production in urban environments, says Andrew A. Meharg.

The growth of slums in the developing world's rapidly expanding cities is creating new opportunities for infectious disease to flourish and spread.

Cities are complex environments. Planning interventions that borrow principles from theoretical physics could help to improve peoples' lives.

Flood losses in coastal cities will rise due to increasing populations and assets. Research now quantifies average losses in the 136 largest coastal cities. Estimated at approximately US$6 billion in 2005, average annual losses could increase to US$52 billion by 2050 on the basis of projected socio-economic change alone. If climate change and subsidence are also considered, current protection will need to be upgraded to avoid unacceptable losses.

Primary and secondary organic aerosols emitted by road vehicles are hazardous to health and climate, with diesel trucks and cars considered the main offenders. Platt et al.show that, despite constituting a small fraction of the fleet, two-stroke scooters can dominate vehicular pollution in some cities.

An enduring paradox of urban economics is why cities support levels of enterprise, such as patents and inventions, higher than the countryside. Here Pentland et al. suggest that the density of social ties provides a greater flow of ideas, resulting in increased productivity and innovation.

Climate modelling is used to show that for cities across North America, geographic variations in daytime urban heat islands—that is, the temperature differences between urban and adjacent rural areas—are largely explained by variations in the efficiency with which those areas convect heat to the lower atmosphere.