Air Quality and Volcanic Ash - Mace Head observations

Date released: Apr 20 2010

The monitoring, assessment and management of air quality in Ireland is carried out, by the EPA, in accordance with the requirements of the EU Air Quality Framework Directive.

To assess air quality, the EPA measures a range of air pollutants which can impact on human health and the environment.  Two of these, SO2 (sulphur dioxide) and PM10 (dust) are in the volcanic plume, and measurements of these will increase if the plume reaches the ground.

Through its research programme, the EPA supports research and observation systems at Mace Head.  Dilute signals, which may be associated with the volcanic eruption in Iceland, have been observed at Mace Head including:
• increased levels of particulate sulphate and
• observations of a high altitude dust layer.

The increases observed at Mace Head are relatively small and they have not impacted on standard air quality measurements carried out by the EPA. In the past 24 hours, hourly measurements of PM10 - of which sulphate is a small part - varied from 14 to 40.  This is a normal daily variation, therefore the EPA’s PM10 monitors would not record this as an unusual increase.

As a precautionary measure, the EPA has increased its air quality monitoring activity for the duration of the ash cloud event and is monitoring the situation on an hourly basis. Data from monitoring stations is transmitted to the EPA website in real-time and can be viewed at