Efficacy of mathematical models in predicting the concentration of indoor radon in areas with highlevels of natural background radiation

Background: indoor levels of 222rn in some residential areas in ramsar are ashigh as 31,000 bq/m3, resulting in mean internal exposures up to 71 msv/y.the main goal of this study was to develop a simple mathematical model forpredicting radon concentrationfrom gamma radiation level in dwellingslocated in high background radiation areas (hbras) and a nearby normalbackground radiation area (nbra) of ramsar. materials and methods: thelevels of gamma background radiation and indoor radon were measured in350 dwellings located in normal and high background radiation areas (210dwellings from hbras and 140 dwellings from nbras). moreover, data aboutthe most important environmental factors such as temperature and humidityas well as the inhabitants’ nutrition were collected. results: the mathematicalrelationship between the gamma radiation level and indoor radonconcentration in nbras and hbras is introduced in this study. the findingsobtained in this study clearly indicate that in normal and high background radiation areas of ramsar the majority of confounding factors such as the type of building materials and ventilation in different houses are almost identical. therefore, the level of gamma radiation can be used as a strong predictive tool for radon concentration. conclusion: as radon concentrationin indoor air strongly varies with time, the simple mathematical methodsdeveloped in this study, can help health physicists and environmentalscientists have an estimate of the mean radon level in these areas.