EPA - Ireland's Environment, An Integrated Assessment - 2020

Chapter 3: Air Quality In terms of ambient air quality, the main source of nitrogen oxides in Ireland is road transport. Diesel vehicles produce more nitrogen oxides than petrol vehicles, particularly older diesels vehicles. Other sources of nitrogen oxides in Ireland include non-road mobile machinery, for example heavy plant machinery, agricultural machinery, industry including energy production, and construction activities. Measurements indicated an exceedance of the nitrogen dioxide EU limit value at one of the monitoring locations in Dublin during 2019. Figure 3.9 details the annual average concentrations of nitrogen dioxide across the country from 2009 to 2019. Levels of nitrogen dioxide from transport decreased from 2009 to 2012; this may have been a result of decreased economic activity and favourable meteorological conditions. The highest nitrogen dioxide levels currently are associated with urban areas with the heaviest traffic. Two new air monitoring stations focusing on emissions from road traffic were installed in Dublin in 2018 (St John’s Road West near Heuston Railway Station) and 2019 (Pearse Street) (Topic Box 3.3). The annual average nitrogen dioxide level at the St John’s Road West site was 43 μg/m 3 – an 8 per cent exceedance of the nitrogen dioxide EU limit value of 40 μg/m 3 in Dublin for 2019 (EPA, 2020). Levels of nitrogen dioxide in other zones were below the EU limit value at the locations monitored. Under EU legislation, an Air Quality Action Plan is required from local authorities in the Dublin area to outline measures to reduce levels. As part of this process, the DECC and Department of Transport, Tourism and Sport have established the Urban Transport-Related Air Pollution Steering Group to address nitrogen dioxide and other traffic-related air pollution in Dublin. Figure 3.9  Annual mean nitrogen dioxide concentrations from 2009 to 2019 (Source: EPA) 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 Annual mean μg/m 3 Year 0 5 10 15 20 25 30 35 40 45 50 ANNUAL LIMIT VALUE Zone A traffic (Dublin) Zone A background (Dublin) Zone B traffic (Cork) Zone C (Large Towns) Zone D (Rural) 73