The radioactive gas radon (²²²Rn) is the predominant terrestrial ionizing radiation that leads to natural radiation exposure. Its occurrence is controlled by the presence of generally weak concentration levels of uranium disseminated in all soils and rocks at the surface, besides other factors such as local geological and atmospheric features that control its release and dissipation into the surrounding air. Inhalation of air containing excess radon is considered harmful on account of radiological hazard posed by its short-lived chemically reactive radioactive decay products. The present work deals with radon estimation in top-soil airs in the Bakreswar geothermal area of West Bengal, India. This region is characterized by several geological faults and very high heat-flow of approximately 230 mW/m². Radon measurements were made at several locations scattered around Bakreswar and Tantloi. Radon exhalation rate from soil was also observed continuously for 24 hours at three different locations on three sides of the hot spring Agnikunda, and inhalation doses estimated for indoor radon at each of these three locations.

Keywords: Environment Pollution; Health Hazard; Radioactivity; ²²²Rn;