Another Olympic legacy in the air

Wednesday 22nd Aug 2012 by theWeather Club

With one hugely successful Olympic Games behind us and the Paralympics about to get underway, scientists are busily working around London in the biggest air monitoring exercise in the city's history. Weather conditions could make a crucial difference to whether pollution rises to significantly high levels during the games, and the National Centre for Atmospheric Science (NCAS) is running an experiment to investigate how weather, chemistry and the amount of traffic all interact to affect air pollution.

The games will act as a real-life experiment allowing scientists to investigate how changes in traffic density and traffic flow affect air pollution. By improving our ability to forecast air pollution, the effect of future changes to traffic patterns as a way of reducing pollution exposure can be assessed, potentially leading to an Olympic legacy of cleaner air for people in the capital, and cities further afield.

Dr Janet Barlow, is taking part in the project as part of the team from the University of Reading. She said that while the wet summer weather might have been unwelcome, it has been helping to keep the air relatively clean. However, Met Office forecasts for warmer and more changeable weather in the weeks ahead suggest pollution could still be an issue for athletes, visitors and native Londoners alike. She continued: "The current sunny weather is a welcome departure from all the rain we've been having, but it brings with it its own problems.” In particularly hot weather levels of ozone can exceed European and The Department for Environment, Food and Rural Affairs (Defra) safety thresholds. These are the threshold values for protection of human health, beyond which Defra advises adults and children with lung problems, and adults with heart problems, who experience symptoms, to consider reducing strenuous physical activity, particularly outdoors.

The measurements are being taken as part of the three-year Clean Air for London (ClearfLo) project, and participants are hopeful that the Games will provide crucial data that could help planners to cut pollution across the city in the future. "One of the aims of the ClearFlo project is to be able to provide more accurate air pollution forecasts in the future, with less uncertainty about forecast pollution levels and information available for individual neighbourhoods, rather than just regions."

As part of the monitoring exercise, six shipping containers of equipment have been set up in the playground of a to monitor pollutants like ozone, which can exacerbate breathing and heart problems and which can build up when fumes from traffic exhausts react in hot, sunny weather. Particulates - tiny particles that can penetrate the lungs - are also being measured on the ground and by lasers scanning the London skies. This temporary laboratory collected data from 23rd July to 17th August.

Equipment on the top of the BT Tower also provided vital measurements of conditions above ground helping to give a unique 3D picture of air flow, moisture and chemistry and how they control air pollution at street level "London is such a busy city that it's not often that we get a chance to measure the effect of major changes to traffic patterns on air pollution," Dr Barlow said. "It would be wonderful if our work this summer contributed to cleaner air for millions of Londoners. That would be an Olympic legacy to really be proud of."