Radon transport to indoor air in groundwater plants as a by-effect of different water treatments

Radon released from groundwater into indoor air is the main radiation safety problem for water treatment plants. This study investigated the release of radon from different water treatment processes and the effect of ventilation on the indoor radon concentration at six waterworks. In addition to various aeration processes, groundwater pretreatments, such as activated carbon and pre-ozonation, were demonstrated to be associated with the indoor radon concentration. This study revealed that accurate assessment of radon exposure at water treatment plants is very difficult because of the large and sudden temporal variations in the radon concentration and smaller local variations that follow the steps of the water treatment process and ventilation. Based on the study, concrete proposals are also presented for improving radiation safety and the reliability of measurements.