Determine the Contaminations of Radon in the Drinking Water Using NTDs (CR-39) and RAD7 Detectors

This presented study was performed to determine the contaminations of radon in twenty-five drinking tap water samples in Penang/Malaysia. The concentration of 222Rn, specific activity of 226Ra, radon emanation factor, equilibrium radon concentration, annual effective dose and mass exhalation rate were measured in drinking water samples available under study by using two methods, passive method (NTDs (CR-39) and active method (RAD7 monitoring). Also, the pH and electrical conductivity of the samples were measured. The results showed that the maximum concentration of radon was found in sample 7 to be 98.154 Bq m−3 and the minimum concentration of radon was found in sample 4 to be 39.715 Bq m−3 with an average of 66.521 Bq m−3. The maximum concentration of radium was found in sample 7 to be 1266.036 × 10−3 Bq kg−1, and the minimum concentration of radium was found in sample 4 to be 530.729 × 10−3 Bq kg−1 with an average (899.999 × 10−3 Bq kg−1). The results obtained from the passive technique (CR-39) and active technique (RAD7) were in good agreement together (66.521, 63.533) Bq m−3, because the passive method and active method are simple and reliable analytical methods. An average annual effective dose (0.770 mSvy−1) was found to be below the value (3–10 mSvy−1) that was reported by the ICRP (1993), therefore, there is no evidence of health problems. Significant strong positive correlations found (r = 1, Pearson Correlation, p < 0.000) in concentrations of radon, radium and annual effective dose. All the results obtained were within the international levels as given by UNSCEAR (United Nations Scientific Committee on the Effect of Atomic Radiation).