2004 IRISH SCIENTIST YEAR BOOK

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Radiological Protection Institute of Ireland
Savio Sequeira & Leo McKittrick
Radon in private drinking water supplies in County Wicklow

Results of the Pilot Study in Wicklow

Radon gas comes from the radioactive decay of uranium which occurs naturally in the environment. Radon is soluble in water and thus may accumulate in water as it passes over rocks and through soil. The dissolved radon is transported in the water and can then find its way into domestic ground water supplies such as wells and boreholes. Ingestion of dissolved radon will result in a radiation dose to the lining of the stomach. In addition, radon released from the water into the air may also result in inhalation doses to the lungs. However, a definitive link between the ingestion of radon-bearing water and cancer has not been established, whereas the link between radon in air and lung cancer has been proven.

A European Commission Recommendation [EC, 2001/928/Euratom] proposes that surveys should be undertaken in Member States to determine the scale and nature of exposures caused by radon in domestic drinking water supplies. The Commission recommends 1000 Bq/l (becquerels per litre) as the radon concentration in private drinking water above which remedial action to reduce the concentration should be considered. To this end, a pilot study of radon in drinking water in County Wicklow was carried out in 2002. County Wicklow was selected for the study on the basis that high radon concentrations in air have been predicted in a significant number of dwellings in the County, the underlying geology is predominantly granite with an anticipated elevated uranium content, and there is a high usage of drinking water from private supplies, estimated at between 1200 and 5000.


Water samples being analysed for radon by liquid scintillation counting

Drinking water from over 150 houses that use water from boreholes as their primary supply in County Wicklow was analysed for radon. The results of the study, shown in the pie-chart, indicate that four houses (2.4% of the total) exceeded the EC Recommendation level of 1000 Bq/l. The Institute recommended remediation of these supplies to reduce the radon levels.

The study of radon in drinking water in Ireland is ongoing and the Institute now offers a routine service for this analysis.

Contact: Dr Savio Sequeira,
Radiological Protection Institute of Ireland, 3 Clonskeagh Square, Dublin 14; Tel: 01-2697766;
E-mail: [email protected] ; Web: www.rpii.ie