In the study area, 37 villages were chosen for ana- lysis of radon concentration in water samples. From each village four water samples were taken and ana- lysed for radon concentration. The water samples were collected from individual home wells normally operated with hand pumps. The water directly from the tap is used by the residents. Before the samples were taken, the water was pumped out 5–10 min until fresh water comes from deep in the well. The water samples were taken in 250-ml vials. In the present research, as a sample was collected, it was analysed immediately on the entire sampling site. The time difference between taking the sample and analysing it was few minutes, so no decay of radon in the water occured.