Vehicles might be responsible for the air pollution in urban areas, but the traffic lights are making us inhale even more deadly gases, according to a new study. Researchers found out that traffic intersections managed by lights contribute to about 25% of total exposure to polluting nanoparticles that cause respiratory and heart diseases. While monitoring the exposure to air pollutants at various points of a journey, scientists from the University of Surrey, in UK, discovered that intersections are high pollution hot-spots because of the the frequent changes in driving conditions. Just because the cars are decelerating and stopping and then moving quickly when lights go green, the particle concentration is 29 times higher compared to free flowing traffic conditions.
Also, because the vehicles tend to be close together at lights, the exposure to emissions is significantly increased and, with limited options on the road, the only way people can protect themselves is by isolating in their cars. “Our time spent traveling in cars has remain 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”, said lead author, Dr Prashant Kumar, from the University of Surrey.
“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 try to increase the distance between you and the car in front where possible.” But not only the drivers are in danger in these areas. The same study notes that pedestrians regularly crossing such routes should look for other paths less dependent on traffic light crossings and suggests that transport agencies could help by synchronizing traffic signals to reduce waiting time and consider alternative traffic management systems such as flyovers.
Air pollution is placed in the top ten health risks faced by human beings, the World Health Organization linking it to seven million premature deaths every year. The results were published in the journal Atmospheric Environment.