Activity concentration and dose estimation of 226Ra, 232Th, 40K and 137Cs in drinking water of selected areas of Punjab, Pakistan.

Radioactivity of naturally occurring (²²⁶Ra, ²³²Th and ⁴⁰K) and anthropogenic (¹³⁷Cs) radioactive nuclides was measured in 29 potable ground and surface water samples of Punjab, Pakistan. The results showed average activity concentrations for ²²⁶Ra, ²³²Th, ⁴⁰K and ¹³⁷Cs as 1.09, 0.55, 16.17 and 0.40 Bql^-1, respectively. ¹³⁷Cs was detected in only a few samples. The obtained results showed that, in general, activity concentrations of radionuclides (²³²Th and ¹³⁷Cs) in drinking water samples did not exceed WHO recommendations. ²²⁶Ra in the majority of samples exceeded WHO drinking water guidelines. The estimated committed effective dose due to intake of the water for three age-groups considered (<1 y, 2-7 y and -17 y) was below the ICRP permissible limit (0.1 mSvy^-1) except for ²²⁶Ra and ⁴⁰K. [ABSTRACT FROM AUTHOR]