Evaluation of drinking water radioactivity content and radiological risk assessment: A new methodological approach

The presence of radionuclides in drinking water constitutes a health risk for humans, because the consumption of such water increases the likelihood of incurring cancer. In our laboratory a new methodological approach was developed, in order to evaluate the radioactivity content and to assess the radiological risk, through the calculation of the Indicative Dose (ID) due to ingestion, in the case of exceeding gross alpha (the most common situation of exceeding the parameter values for the screening ones). In this study, liquid scintillation counting (LSC) was employed to measure the activity concentration of gross alpha and beta in drinking water samples from springs and boreholes. The objective was to evaluate the ID if the gross alpha/beta activities acceeded the stipulated limit. Selective extraction of uranium was performed after which the sample were counted using the liquid scintillator. The resultant spectrum was then deconvoluted using the Peakfit Software. 238U (ppb) concentration and of the 226Ra specific activity were determined using ICP-MS and LSC, respectively.