Dose assessment due to natural gamma radiation levels and radioactive nuclides in the environment of Dasarlapally, Nalgonda District, Telangana State, India

ABSTRACT

Gamma radiation levels in the indoors and outdoors of Dasarlapally, a village in the environs of uranium mineralised area, were measured with μR- survey metre and Thermoluminescence Dosimeters (TLDs). The measured gamma radiation absorbed dose in the study area varied between 1744 and 2663 µGy y⁻¹ with an average of 2327 ± 505 µGy y⁻¹. The ratio of indoor to outdoor gamma radiation levels was found to be varied from 0.92 to 1.54 with an average of 1.09. The soil samples were analysed for radioactive elements ²²⁶Ra, ²³²Th and ⁴⁰K using gamma ray spectrometer and found that the concentration of radioactive nuclides, radium and thorium, is three times and five times higher than global average, respectively, whereas the potassium activity is lower than the global. The external absorbed dose rate due to radioactive nuclides present in the soil and associated hazard index parameters were also calculated.

KEYWORDS:

• Uranium
• gamma radiation
• absorbed dose
• radioactive elements
• TLDS

Article highlights

• Natural gamma radiation levels were estimated in the environs of proposed uranium mining site with two different techniques.

• The estimated average gamma radiation levels and radionuclides (radium and thorium) are relatively higher than national and global average

• The ratio of thorium to radium is found to be 1.42. It is an indication that the contribution of thorium to the inhalation dose is significant.

• In the present study, the internal index value is found to be little higher than unity.

Acknowledgements

This work was supported by Atomic Energy Regulatory Board (AERB), through a research project sanctioned vide Lr. No. AERB/ CSRP/ Proj. No. 60/14/2015, dated: 12/05/2015. One of the authors, Mr. G. Suman, gratefully acknowledges the financial support provided by AERB in the form of fellowship to carry out this work. The authors are profoundly thankful to Prof. K. Rama Reddy for his endless and invaluable support.

Authors’ contribution

All authors were concerned for the field studies, involved in the formal analysis of data, interpretation of results, supervision and drafting of the original manuscript.

Disclosure statement

The author(s) declared no conflict of interest with respect to the research, authorship, and financial benefit in publication of this article.