Indoor radon concentrations in workplaces and dwellings in North-Western Greece

Measurements of indoor radon concentrations were performed in 44 workplaces and 87 dwellings in the region of Epirus, north-western Greece, using electret and alpha-track detectors. Radon concentrations followed a log-normal distribution with an arithmetic mean of (92 ± 54) Bq m-3 in workplaces and (86 ± 52) Bq m-3 in dwellings. In all cases, radon levels were below 400 Bq m-3, which is the action level proposed by the European Commission. Comparing summer and winter measurements, no statistically significant seasonal variation was established. However, radon concentrations measured in basement and ground floor levels were significantly higher (p < 0.001) than those measured in the first and upper floors. A mean annual effective dose of 0.64 and 1.63 mSv y-1 was estimated for occupational and residential exposure, respectively. The reported data contribute to the assessment of radon distribution and dose estimate at the national level