Traffic lights expose drivers to more pollution13/02/15Health
UK: Researchers at the UK’s University of Surrey have found that although drivers spend just 2% of their journey time passing through intersections managed by traffic lights, this short duration contributes to about 25% of total exposure to polluting nanoparticles which contribute to respiratory and heart diseases.
The team monitored drivers’ exposure to air pollutants at various points of a journey. Signalised traffic intersections were found to be high pollution hotspots due to the frequent changes in driving conditions. With drivers decelerating and stopping at lights, then revving up to move quickly when lights go green, peak particle concentration was found to be 29 times higher than that during free flowing traffic conditions. As well as concentration, researchers found that as cars tend to be close together at lights, the likelihood of exposure to vehicle emissions is also significantly increased.
Lead author Dr Prashant Kumar, from the University of Surrey, said: “Air pollution was recently placed in the top ten health risks faced by human beings globally, with the World Health Organization linking air pollution to seven million premature deaths every year. Our time spent travelling in cars has remained fairly constant during the past decade despite the efforts to reduce it, and with more cars than ever joining the roads, we are being exposed to increasing levels of air pollution as we undertake our daily commutes.”
He added: “It’s not always possible to change your route to avoid these intersections, but drivers should be aware of the increased risks at busy lights. The best ways to limit your exposure is to keep vehicle windows shut, fans off and to try to increase the distance between you and the car in front where possible. Pedestrians regularly crossing such routes should consider whether there might be other paths less dependent on traffic light crossings. Local transport agencies could also help by synchronising traffic signals to reduce waiting time and consider alternative traffic management systems such as flyovers.”