Keywords: thoron exposure, caves, makrofol-E detectors, tour guides, Brazil, low radiation, thoron concentrations, dose rate
Thoron exposure among tour guides in southern Brazilian show caves
An assessment of thoron concentration was carried out in the most visited caves of the natural state park in Brazil, 'Parque Estadual do Alto Ribeira' (PETAR), by using Makrofol E nuclear track detectors placed in twin chambers. PETAR, a natural park, was created in 1958 and is located in the southern region of Sao Paulo State. Detectors were placed in the caves most visited by tourists. Tour guides were evaluated for committed effective doses caused by thoron inhalation, giving results between 0.005 and 0.017 mSv•y-1.