Local authorities around the State have largely ignored a warning to have their mains water supplies tested for the presence of radioactive radon gas.
No more than eight of the 70 to 80 authorities written to last November responded to the warning issued by the Radiological Protection Institute of Ireland.
The institute yesterday said it had not the resources to test all or even a large fraction of the estimated 150,000 private water supplies across the State for radon gas. This follows a call yesterday from the Green Party for extensive national testing for radon gas in drinking water supplies.
On Monday the institute published a report showing that a small fraction of homes in Co Wicklow were using private wells contaminated with unacceptably high levels of radon gas. This raised the possibility that wells in many other counties known to have high radon levels in soils could also exceed drinking water radon levels set by an EU directive.
It has emerged, however, that four months ago the institute advised all local authorities to have their mains water tested for radon levels. Very few have so far asked the institute to carry out tests according to Dr Tony Colgan, principal scientific officer at the institute.
"We offer our measurement services to anyone who wants measurements made," he said yesterday. "We advised every county council and local authority to have tests done."
The tests were advised for any local authority that had a mains supply sourced from ground water. High radon levels were not an issue with supplies coming from surface waters such as lakes and rivers where the radioactive gas can escape into the air.
No more than eight authorities had responded so far, he said, although not all authorities relied on ground water mains supplies. None of the mains water samples tested so far had levels anywhere near the EU's "action level" of 1,000 becquerels per litre of water, Dr Colgan said. "In all the samples we analysed so far we haven't found any sample above 100 becquerels per litre."
The county council paid for all the pilot tests on 166 water supplies in the Co Wicklow study, he said. No further tests had been requested, however.
There were an estimated 150,000 borehole wells across the State, he said. The resources of the RPII were "not sufficient to do a national study" unless the Department of the Environment and Local Government decided to fund a special study.
The Green Party yesterday called for "extensive testing for radon nationally" following the release of the institute's drinking water study.
Evidence of unacceptably high radon levels in Wicklow drinking water was "very disturbing" according to Mr Sean Power TD, chair of the Dáil Committee on Environment and Local Government.