One in four schools in a survey was affected by unacceptably high levels of the naturally occurring radioactive gas, radon, and the Department of Education and Science has been urged to take remedial action.
One school had levels of radon 13 times higher than the safety limit set by the Radiological Protection Institute of Ireland (RPII), above which remedial measures are advised.
The institute surveyed 685 schools in counties Carlow, Cavan, Kildare, Kilkenny, Louth, Meath, Monaghan, Westmeath, Wexford and Wicklow. The survey identified 175 schools where the levels of radon exceeded the safety limit.
The institute has requested urgent action by the Department of Education and Science to reduce the levels, according to its chief executive, Dr Tom O'Flaherty. "We are urging them to deal with the most affected schools very quickly."
While it was not necessary to consider taking students out of the worst affected schools, long-term exposure to radon is associated with an increased risk of developing lung cancer, he said. "There is a range of levels in the schools that are affected, and the timetable for doing remedial work would be related to the levels that are there."
"The work itself will not take that long," Dr O'Flaherty said, and would reduce radon levels to well below the action level.
The RPII measured for radon over a full school year in every occupied ground-floor room in each participating school. It measured for the gas in becquerels (bq) per cubic metre and applied an internationally recognised limit of 200 bq as its "National Reference Level".
The highest reading was 2,600 bq, but Dr O'Flaherty would not identify the county in which this occurred. Six of the schools had at least one reading above 1,000 bq, he said, but most readings were only marginally above the 200 bq level.
Samples taken in Co Wicklow identified a particular problem there with 35 of the 84 schools surveyed requiring remedial action. On a percentage basis, Co Carlow has a comparable problem with 17 schools of the 42 surveyed requiring action.
The Minister for Education and Science, Mr Martin, is scheduled to make an announcement in response to the institute's study within the next few days, according to a spokesman at the Department.
This is the first of three surveys of schools and included about 80 per cent of all schools in the 10 counties. Some failed to participate but these would now be contacted in follow-up surveys, Dr O'Flaherty said.
The other counties will be included in later surveys.
