Changes to city design can have 'significant' impact on health: study

Case studies in major cities across the world including London, Boston and New Delhi suggest that changes to city design and transport can have "significant" impact on health including reductions in non-communicable diseases which India is presently reeling under.

A new Series, published in 'The Lancet' quantifies the health gains that could be achieved if cities incentivised a shift from private car use to cycling and walking and promoted a compact city model.

"These changes could achieve significant reductions in non-communicable diseases such as cardiovascular disease and diabetes as well as increasing physical activity and reducing pollution.

"Importantly, in cities with high levels of private car use such as Melbourne, London and Boston, promoting walking and cycling must be matched by improvements to infrastructure that separate motorised transport to protect cyclists and pedestrians from road injuries," the authors said.

The new series on urban design, transport and health was led by the University of Melbourne (Australia) and the University of California, San Diego (USA). The study said that over half of the world's population live in cities and rapid urbanisation is only expected to increase in the coming years.

"By 2050, large cities in the USA, China and India are predicted to see their populations increase by 33 per cent, 38 per cent and 96 per cent respectively. Population growth in cities means increasing demands on transport systems," it said.
It said that private car use has increased dramatically in Brazil, China and India leading to declines in physical activity, increases in air pollution and increased rates of road death and serious injury, all of which combine to increase overall levels of chronic disease and injury.

Series lead Professor Mark Stevenson of University of Melbourne designed a 'compact cities model' where land-use density was increased by 30 per cent, average distance to public transport reduced by 30 per cent and diversity of land-use increased by 30 per cent. The model was applied to six cities - Melbourne, London, Boston, Sao Paulo, Copenhagen and Delhi.

Health gains were predicted in all cities with the greatest effect on reducing rates of cardiovascular disease while all cities saw increases in physical activity and reductions in air pollution from transport emissions.

The study said that in Melbourne, the model led to an estimated reduction of 19 per cent in the burden of cardiovascular disease and 14 per cent in the burden of type 2 diabetes, in London, the model led to a reduction of 13 per cent in the burden of cardiovascular disease and 7 per cent in type 2 diabetes.

Series author Billie Giles-Corti of University of Melbourne in Australia said that with the world's population estimated to reach 10 billion people by 2050, and three quarters of this population living in cities, city planning must be part of a comprehensive solution to tackling adverse health outcomes.

"City planning was key to cutting infectious disease outbreaks in the 19th century through improved sanitation, housing and separating residential and industrial areas.
"Today, there is a real opportunity for city planning to reduce non-communicable diseases and road trauma and to promote health and wellbeing more broadly," he said.

The authors identify key interventions that, when combined, encourage walking, cycling and public transport use, while reducing private car use. These also include having shops and services within walking distance, a mix of employment and housing across the city, reducing the availability and increasing the cost of parking amongst others.

It said that several cities have made progress in increasing walking and cycling including London, Stockholm and Bogota. "City planning policies can affect health, both positively and negatively. Sadly, it is clear that many city leaders around the world are not applying the lessons of research to make cities as healthy as possible.

"A continuing challenge is to improve the communication of this evidence to city leaders and find incentives for them to seek out and apply the evidence," said series author professor James Sallis, University of California, San Diego, USA.