Jul 22, 2010
Urban planning could cut air-pollution woes
Living next to a busy road could knock years off your life. This is the unpalatable conclusion reached by Michael Brauer of the University of British Columbia in Vancouver, Canada, who assesses the links between traffic pollution and people’s health. But it isn’t all bad news. His research also shows that clever urban planning can help to make the air sweet again.
Air pollution has a major impact on our health. When coal-fires were banned in Dublin, Ireland in 1990, the number of deaths from respiratory diseases decreased by more than 15% and deaths from cardiovascular diseases by more than 10%. Today most cities in developed countries insist on ‘smokeless’ fuel being burnt in homes, but still air pollution is a major threat, particularly near congested roads.
Over the last six years Brauer and colleagues have been evaluating the air pollution in the Seattle and Vancouver area, and its relationship to human health. They’ve mapped people’s exposure to eight major pollutants – CO, NO, NO2, SO2, ozone, PM2.5, PM10 and black carbon – according to post code, and used medical records to analyse the link with health.
Their results showed that “mums-to-be” who lived within 50 m of a major road were 26% more likely to have a low-birth-weight baby and had a greater chance of a premature birth, compared with women living more than 50 m from a major road. “This then puts children at increased risk for a large number of health problems throughout their lives,” explains Brauer. What’s more, children living near busy highways were 13% more likely to develop asthma, 6% more likely to develop bronchiolitis and around 8% more likely to experience middle-ear infections.
And it isn’t just babies and children who are at risk. Brauer and colleagues have also found a strong link between traffic pollution and death from cardiovascular disease. “We show that people who move away from high-traffic roads reduce their risk of cardiovascular-disease death compared with people who do not,” Brauer told environmentalresearchweb. Specifically their study revealed that people who move from within 50 m of a major highway reduce their risk by 45%.
So what can be done to improve the situation? Working with urban planners, Brauer argues that encouraging people to get out of their cars, and designing transport systems that separate cars from walking areas and cycle routes, can make a huge difference. By characterising neighbourhoods with high numbers of walking and cycling routes, and low levels of air pollution, Brauer and his colleagues are identifying layouts that work and hope to be able to replicate this pattern elsewhere. “Urban and transportation planning needs to become smarter designing cities for people, not just cars,” says Brauer, who has been a keen cyclist all of his life.
To aid this progression Brauer and colleagues have developed a web-based cycle trip planner for the people of Vancouver. “This allows users to select cycling routes based on preferences such as fewer hills, more green space and less air pollution,” explains Brauer.
Thinking on a bigger scale Brauer is also involved in a project studying the global burden of disease from air pollution. Using conventional measurements, satellite data and chemical transport models, researchers are estimating how air pollution varies across the globe. “From this assessment it is quite clear that the places where air pollution has the greatest impact on health high concentrations intersecting with high population density are in China, India and South-East Asia,” says Brauer. Meanwhile, megacities in Africa are of growing concern.
Without a doubt air pollution is a big problem around the world but there are easy ways to reduce the burden. Within cities, careful urban and transport planning, such as setting roads back from pavements, improving accessibility for cyclists and pedestrians, having dedicated truck routes and congestion charging can make an immense difference. Meanwhile, controlling household and industrial emissions is important too. And the good news is that these measures make economic sense. “Air quality management is very good value for money,” says Brauer.
About the author
Kate Ravilious is a contributing editor to environmentalresearchweb.