Relative dose / exposure to air pollutants between modes of transport, while commuting to work in Dublin

Abstract

Research was carried out into the relative exposure of commuters to air pollutants in Dublin between four modes of transport. These differences were determined experimentally by simultaneously sampling the personal exposure of commuters to VOCs and PM2 5 in cars, buses, on bicycles and on foot. Over 400 samples were recorded from January 2005 to June 2006 along two different commuter routes (Route 1 and 2) and the resulting dataset revealed statistically significant differences between exposure concentrations in the modes of transport. The Car commuter was found to have the highest exposure to VOCs followed by the bus, cyclist and pedestrian, while the bus had the highest exposure to PM2.5 followed by the car, cyclist and pedestrian. Using a numerical lung model to predict the internal deposition and absorption of these harmful pollutants revealed that for PM2 5 the cyclists had the highest uptake due to their elevated breathing rates, followed by the bus, pedestrian and car. For VOCs the car was found to have the highest uptake, owing to its high exposure concentration and long duration of exposure, followed by the cyclist, pedestrian and bus. Samples were recorded using mobile sampling equipment and analysed using gas chromatography for VOCs and gravimetric analysis for PM2 5.