Airing the city

Mothballs contribute to healthier urban ventilation Air quality in urban areas could be improved by changing street layout and building design - and naphthalene, an aromatic hydrocarbon used in mothballs, could help scientists work out how to do it. Built-up areas have pollution ‘hotspots’, caused when street-level emissions and heat are trapped by buildings. These hotspots can aggravate respiratory conditions such as asthma and contribute to a local greenhouse effect. Researchers from the University of Reading now plan to build model cities with buildings coated in naphthalene, which is carried on the air in a similar way to heat and pollution. And what will they do with these smelly models? Take them into a wind tunnel, of course - the EnFlo wind tunnel at the University of Surrey, to be precise - to do experiments on how pollution levels vary with changes in street layout and the size and shape of buildings. According to Janet Barlow of Reading’s Department of Meteorology, better understanding of heat and pollution ventilation rates could help architects and town planners “promote more sustainable, more comfortable and healthier urban environments”. Robert Shaw, policy officer for the Town and Country Planning Association (TCPA), agrees. Describing the study as “particularly useful”, he says it should complement existing TCPA-associated research into how urban areas can adapt to climate change. “Part of this will be considering the impacts of wind and how this will affect the way we plan in the future. This is something that planners ought to take very seriously, but they will need a steer from government.” The Engineering and Physical Sciences Research Council is funding both the Reading research and parallel work elsewhere on how vehicle emissions circulate in cities, as part of the delightfully-acronymed Dispersion of Air Pollution and Penetration into the Local Environment (DAPPLE) project. - Alison Winward

14 March 2004

Alison Winward