An evaluation of the radon concentration in North Carolina ground water supplies

Water samples from 225 North Carolina ground water supplies were analyzed to determine the presence of 222Rn. The results are reported in pCi/l. and range up to a maximum of 46,600. Approximately 33 % of the water supplies analyzed were found to have concentrations greater than 2000 pCi/l. A review of health studies concerning the radiation dose received via drinking water containing radon revealed that most authors have considered the stomach to be the critical organ. These studies indicated that a 222Rn concentration in water in the range of 3000-7000 pCi/l delivers to the stomach the 0.5 rem/yr dose limit recommended by the ICRP for the general population. One study indicated that the inhalation dose resulting from the diffusion of radon from drinking water into the home atmosphere may be even more restrictive than the ingestion dose to the stomach. It is suggested that a standard be set and applied for radon concentrations in water. Radon is poorly soluble in water and may be removed by aeration or other methods to prevent citizens from receiving unnecessary doses. (author)