Particulate Matter, a term used to describe all the suspended aerosols and particles in the atmosphere, has been identified as one of the most problematic pollutants across Ireland. Diesel vehicles in particular are known for their significant contribution to overall emissions of particulate matter in the atmosphere, and therefore constitute a significant threat to public health and the environment.
In 2008 the Irish Government instigated a new annual vehicle taxation system whereby vehicles purchased would be taxed based on their CO2 emissions intensity rather than their engine capacity. This resulted in a major increase in the number of diesel passenger vehicles in the Irish fleet, due to the lower CO2 emissions of diesel engines. However, a recent investigation of national emissions in the road transport sector in Ireland has highlighted that private diesel passenger vehicles now contribute the largest proportion of total emissions in both CO2 and particulate matter of all vehicle categories. This finding has a major implication for the directionof CO2 emission control policy in the transport sector in Ireland, and the growth of passenger diesel car numbers in recent years needs to be addressed, as this vehicle category represents a significant pressure on the quality of the urban environment in Ireland. In order to determine the impact of the growing levels of diesel particulate emissions in Ireland on the population and public health, exposure and health impact assessments must be carried out to determine exposure both in transport microenvironments and also in critical indoor locations such as the home and workplace.
Determination of the proportion of total particulate matter concentration in urban areas, which has originated from diesel vehicle emissions using source apportionment techniques, is invaluable in assessing the impact of diesel emissions on population exposure in Ireland. This project will generate evidence on the impact of diesel road transport vehicles in Ireland on the exposure of the population and subsequent health impacts, through field measurement and modelling of personal exposure to PM2.5. The first aim of the project is to estimate the contribution of PM2.5 that can be attributed to emissions from diesel vehicles in Dublin city. The second aim of this project is to determine the exposure of the population to emissions from diesel vehicles in the urban environments. The third aim of this project is to develop models to predict future emissions of PM2.5 in order to assess the impact of future policy, vehicle technology and travel demands on emissions from diesel vehicles. The evidence generated in this project will be of relevance to the implementation of a number of existing policies both nationally and internationally, and will inform the development of new policy in the areas of sustainable transport, public health and climate change.