ABSTRACT

The activity concentrations of the natural radionuclides, namely ²³⁸Ra, ²³²Th and ⁴⁰K, are measured for soil samples collected from some locations of the Malwa region of Punjab. An HPGe detector, based on high-resolution gamma spectrometry system is used for the measurement of activity concentrations. The activity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K in the soil from the studied areas varies from 23.3 Bq kg^–1 (Jagraon) to 43.6 Bq kg^–1 (Ludhiana), 104 Bq kg^–1 (Raikot) to 148 Bq kg^–1 (Kauli) and 290 Bq kg^–1 (Rajpura) to 394 Bq kg^–1 (Sarhind) having an overall mean value of 32 Bq kg^–1, 126 Bq kg^–1 and 348 Bq kg^–1 respectively. The radium equivalent activity (Ra_eq) in these soil samples ranges from 200 Bq kg^–1 (Jagraon) to 264 Bq kg^–1 (Kauli) having a mean value of 237 Bq kg^–1. Corresponding indoor and outdoor annual effective doses range from 0.45 to 0.59 mSv and 0.11 to 0.15 mSv and average 0.53 and 0.13 mSv. The external hazard index (H_ex) for soil samples of the study area are lower than unity; therefore, according to the Radiation Protection 112 (European Commission, 1999) report, soil from these regions is safe and can be used as a construction material without posing any significant radiological threat to population.