Radon is a serious public health issue in Ireland, according to the Radiological Protection Institute.
According to its annual report, four thousand homes across the country have high radon levels.
Radon is a cancer-causing gas, and the report reveals that the vast majority of our exposure to radon comes from sources found naturally in the environment.
The Institute is calling for a national radon strategy, and says there is also a need for a radioactive waste policy.