Air

Please send any additional queries to licensing@epa.ie using the subject heading ‘Medium Combustion Plant’.

Tropospheric, or ground level ozone, is not emitted directly into the air, but is created by chemical reactions between oxides of nitrogen (NOx) and volatile organic compounds (VOC). This happens when pollutants emitted by cars, power plants, industrial boilers, refineries, chemical plants, and other sources chemically react in the presence of sunlight.

Sunshine and heat help ozone to form, so ozone pollution is most likely to be a problem on warm, sunny days.

Another unusual thing about ozone is that it reacts with nitric oxide (NO) which is usually found in towns and cities near roads. As a result, ozone pollution is more of a problem in the countryside than in our cities.

The main source of Sulphur Dioxide in Ireland is burning coal and oil to heat homes and industries and to produce electricity.

It is an irritant gas which attacks the throat and lungs. Prolonged exposure can lead to increases in respiratory illnesses like chronic bronchitis. It contributes to the formation of acid rain, which damages vegetation and buildings.

Levels in Ireland are low to moderate. Overall levels have decreased over recent years due to increased use of low-sulphur "smokeless" coal, increased use of natural gas instead of solid fuels and reduced industrial emissions through IPC licensing.

The main source of Carbon Monoxide in Ireland is traffic. It is absorbed into the bloodstream more readily than oxygen, so the relatively small quantities in inhaled air can have harmful effects.

Prolonged exposure can cause tissue damage and individuals suffering from cardiovascular disease are particularly at risk. Levels in Ireland are low.

PM are a complex mixture of solid and liquid particles of organic and inorganic substances suspended in the air. typically measured as PM₁₀ and PM_2.5 with diameters of 10μm (microns) or 2.5μm. PM is a common proxy indicator for air pollution.

It affects more people than any other pollutant. While particles  with a diameter of 10 microns or less, (≤ PM₁₀) can penetrate and lodge deep inside the lungs, the even more health-damaging particles are those with a diameter of 2.5 microns or less, (≤ PM_2.5). PM_2.5  can penetrate the lung barrier and enter the blood system. Chronic exposure to particles contributes to the risk of developing cardiovascular and respiratory diseases, as well as of lung cancer.

The major components of PM are sulfate, nitrates, ammonia, sodium chloride, black carbon, mineral dust and water. These particles can consist of direct emissions such as dust, emissions from combustion engines, from the burning of solid fuels or natural sources such as windblown salt, plant spores and pollens. These direct emissions are known as primary PM.

PM can also be produced indirectly by formation of aerosols through reactions of other pollutants such as Nitrogen Oxides (NO_X) and Sulphur Dioxide (SO₂); these are known as secondary PM. In Ireland, the main sources are solid fuel burning and vehicular traffic.

Air quality measurements are typically reported in terms of daily or annual mean concentrations of PM₁₀ particles per cubic meter of air volume (m³). Routine air quality measurements typically describe such PM concentrations in terms of micrograms per cubic meter (μg/m³). Concentrations of fine particles (PM_2.5 or smaller), are also reported.