Ireland's State of the Environment Report 2024

46 Chapter 2: Air Sulphur dioxide . SO 2 is the major contributor to acid deposition, which is associated with the acidification of soils and surface waters and the accelerated corrosion of buildings and monuments (Figure 2.10). Emissions of SO 2 are derived from the sulphur in fossil fuels such as the coal and oil used in combustion activities. Ireland is currently compliant with the emission reduction commitment for SO 2 for the period 2020-2029 and is also projected to be compliant with the 2030 reduction commitment. Figure 2.10  Sources of sulphur dioxide emissions in Ireland 19.6% 17.1% 58.7% 1.7% 2.6% 0.3% OTHER Source: EPA, 2024a Fine particulate matter. Ireland is currently compliant with the emission reduction commitment for PM 2.5 for the period 2020-2029 and is projected to also be compliant with the 2030 reduction commitment. However, the narrow margin between compliance and non-compliance in 2030 is of concern and further abatement above and beyond that currently proposed may be required. Figure 2.11 sets out the sources of PM 2.5 emissions in Ireland. Figure 2.11  Sources of fine particulate matter emissions in Ireland 13.2% 12.5% 7.9% 1.1% OTHER 4.1% 49.1% 12.2% Source: EPA, 2024a 4. National ambient air quality monitoring network The EPA’s ambient air monitoring network of 115 stations provides data for the assessment of Ireland’s air quality and supports reporting required under EU legislation. In this context, Ireland is divided into four zones for ambient air quality monitoring and management under the EU directives: zone A, Dublin city; zone B, Cork city; zone C, large towns with a population over 15,000; and zone D, the remainder of the country. The following section summarises the assessment of monitoring results for particulate matter, NO 2 , O 3 and other pollutants in these zones. Particulate matter Particulate matter in air consists of very small particles that have a significant negative impact on health. Primary particulate matter is emitted into the atmosphere from human activities (e.g. burning solid fuel, vehicle exhaust discharges, tyre and road surface wear and construction works) and natural events (e.g. sea salt from sea spray). Secondary particulate matter is formed in the atmosphere from precursor compounds (e.g. NH 3 emissions arising from agricultural activities).