Measurements of activity concentrations of naturally occurring radionuclides in soil samples from Punjab province of Pakistan and assessment of radiological hazards

Abstract

The natural level of radioactivity in soil is one of the major causes of external gamma rays exposure. It was considered imperative to measure gamma-ray activity concentrations due to naturally occurring, potentially hazardous radionuclides from 232Th, 226Ra and 40K in soil samples from Punjab, the most populated province of Pakistan. The activity concentrations were measured in soil samples collected from all 34 district headquarters of Punjab province using a P-type coaxial high purity germanium (HPGe)-based gamma-ray spectrometer having a relative efficiency of 60%. The mean activity concentrations for 232Th, 226Ra and 40K were found to be 41 +/- 8, 35 +/- 7 and 615 +/- 143 Bq kg(-1), respectively in soil samples from all 34 district headquarters of Punjab. The mean values of radium equivalent index (Ra(eq)) and total annual external gamma radiation dose were found to be 141 +/- 27 Bq kg(-1)and 0.38 mSv, respectively. Since these estimated radiological impact assessment factors are lower than the recommended values there seems to be no potential radiological health hazard associated with the soils from the district headquarters in the Punjab province of Pakistan. Geological studies show that most of the soils in Punjab have developed on the extensive fluviatile deposits of five rivers and a stable ratio of natural activity concentrations is observed in soil samples of the areas under study.

CONCENTRATIONS OF 226Ra, 232Th, AND 40K IN THE SOILS OF BANGALORE REGION, INDIA

“…The 226 Ra concentration reported for these two regions is almost four times higher than that observed in the present study. It may be noted that, upon comparison of the results of the present study with those of Punjab and Bahawalpur provinces of Pakistan (Tahir et al 2005 andMatiullah et al 2004, respectively), it is clear that the mean values of all three radionuclides are very much comparable.…”

“…The absorbed dose rate observed in the present study is also almost two times than that of Spain (Baeza et al 1994), but is very much less than that of Turkey (Merdanoglu and Altinsoy 2006). (Tahir et al 2005). This provides a useful guideline in regulating the safety standards on radiation protection for the general public.…”

“…The use of materials whose Ra eq exceeds 370 Bq kg Ϫ1 is discouraged to avoid radiation hazards (Beretka and Mathew 1985). The annual effective dose for a Ra eq of 370 Bq kg Ϫ1 corresponds to the dose limit of 1 mSv for the general population (Tahir et al 2005). In the present work, the Ra eq was calculated using the equation given by Tahir et al (2005) and the values are presented in column 5 of Table 3.…”

“…The annual effective dose for a Ra eq of 370 Bq kg Ϫ1 corresponds to the dose limit of 1 mSv for the general population (Tahir et al 2005). In the present work, the Ra eq was calculated using the equation given by Tahir et al (2005) and the values are presented in column 5 of Table 3. The Ra eq varied in the range 53.4 -345.3 Bq kg Ϫ1 with a mean value of 151.1 Bq kg Ϫ1 , which is well within the permissible limit of 370 Bq kg Ϫ1 .…”

Measurement of soil radioactivity levels and radiation hazard assessment in southern Rechna interfluvial region, Pakistan

“…It may be noted that value of 226 Ra was very close to the measured world average of 50 Bq kg −1 as reported in UNSCEAR (2000). Some Pakistani areas like Lahore (Akhtar et al 2005), Punjab Province (Tahir et al 2005), and Southern Punjab (Fatima et al 2008) have lower 226 Ra levels than that of southern Rechna interfluvial region.…”