Posted on 8 March 2011
Scientists from the University of York’s Environment Department, working in collaboration with City of York Council, monitored exposure to the air pollutant nitrogen dioxide (NO2) on both on and off-road cycle routes in the city over a two-month period.
In York we found that using off-road cycle routes led to a significant reduction in the concentration and exposure to nitrogen dioxide compared to on-road routes
The study, published in the Journal of Environmental Monitoring, shows the mean concentration was reduced by 29 to 41 per cent, while the total dose of NO2, (taking into account the duration of the cycle journeys), was reduced by seven to 35 per cent when cycling on off-road routes in York.
Nitrogen dioxide is a major urban pollutant, mainly emitted from vehicles. High doses of the pollutant can inflame the lungs, while prolonged exposure to lower doses can reduce the ability of the lung to function, especially in people with weak respiratory immune systems, such as asthmatics and senior citizens.
The research, carried out with the City of York Council Environmental Protection Unit, provides a simple and cost effective method for other local authorities to quantify the exposure of cyclists to the air pollutant NO2. York researchers extended the authority’s existing diffusion tube network which is used to routinely monitor air pollution across the city.
Tom Bean of the University of York’s Environment Department said: “Our study aimed to develop and apply a simple monitoring method that could be routinely used by transport and air quality planners in local authorities to estimate the difference in exposure of cyclists to NO2 between on-road and off-road routes.
“Other local authorities could readily conduct similar studies by extending their existing diffusion tube networks. In York we found that using off-road cycle routes led to a significant reduction in the concentration and exposure to nitrogen dioxide compared to on-road routes, proving that the provision of additional off-road cycle routes has benefits beyond improved road safety.”
York is regarded as one of the best cycling cities in the UK and was recently awarded Cycling City status.
Mike Southcombe, Environmental Protection Manager for City of York Council, said: “I welcome this report, but off road cycling may not be practical in all parts of the city, therefore the aim must be to reduce traffic pollution throughout York. The Environmental Protection Unit of City of York Council is developing a Low Emission Strategy to reduce harmful emissions from traffic and other sources and carbon dioxide emissions.”
The University of York researchers cycled three typical commuter routes each morning. For each journey, an on-road and off-road route version of the journey was used, giving six routes in total. Measurements of NO2 concentrations were taken at regular intervals along all six routes.
York has an existing network of over 300 NO2 diffusion tubes in and around the city as part of the City of York Council’s air quality monitoring strategy. For the purposes of the study, 50 additional tubes were added to fill gaps along the six cycle routes.