Ambient Air Quality

Air quality in Ireland is assessed by measuring concentrations of pollutants at a number of locations around the country and comparing the results with air quality standards and limit values that have been established at EU level.  Many of these measurements are made in real-time, updated hourly and can be viewed on-line at

Sulphur dioxide

Sulphur dioxide is formed when coal and oil containing sulphur is burned.  Such burning takes place in power stations to generate electricity, in homes and offices for heat, and in vehicles for transport.

Sulphur dioxide is dangerous because high concentrations of the gas, even for a short period, can cause breathing difficulties for people suffering from asthma. Longer-term exposure to high concentrations, along with high levels of particulate matter, can aggravate heart problems, respiratory illness and can damage the lungs' defenses.

Together, sulphur dioxide and oxides of nitrogen are the main causes of acid rain.  These gases are converted to acids by water vapour in the air and fall as rain with a low pH.  This rain makes the streams and lakes acidic and releases heavy metals from the soil. It also damages forests and speeds up the corrosion of buildings and monuments. 

Trends in annual mean SO2 concentrations 2002 - 2012
Air Quality in Ireland 2012 (EPA, 2013)

The graph above shows the trend in average annual sulphur dioxide levels from a number of monitoring stations around the country for the years 2002 – 2012. Zone A is Dublin, Zone B is Cork and Zone D is the remainder of the country. The results are compared against a limit value for ecosystem damage and show that levels are low and have generally declined over the past number of years. This decline is due, in part, to the ban on bituminous coal in the larger cities and towns of Ireland, to the switch away from coal towards oil and gas and to the reduction in the sulphur content of fuel oil in order to comply with EU directives. More air quality charts and an interactive air quality map can be found on the EPA's website under Air Quality.

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