Title: Natural radioactivity and hazardous index of major South Indian river sediments

Authors: S. Murugesan; S. Mullainathan; V. Ramasamy

Addresses: Department of Physics, Sathyabama University, Chennai 600119, Tamil Nadu, India ' Department of Physics, A.V.C. College of Engineering, Mayiladuthurai 609305, Tamil Nadu, India ' Department of Physics, Annamalai University, Annamalai Nagar 608002, Tamil Nadu, India

Abstract: The activity concentrations of ²³⁸U, ²³²Th and ⁴⁰K have been determined by gamma ray spectrometry with an NaI(Tl) detector in sediments of Palar River, Tamil Nadu, India. The absorbed dose rate, radium equivalent concentration, external (H_ex) and internal (H_in) hazardous indices are calculated from criteria formula and compared with the international recommended limits. The Radioactive Heat Production (RHP) rate and Excess Lifetime Cancer Risk (ELCR) are also calculated. The observed dose rate from ERDM (Environmental Radiation Dosimeter) at 1 m above the ground level at each site of the river is measured and correlated with calculated absorbed dose rate. The distribution of quartz, feldspar, magnetic susceptibility and weight of the magnetic minerals is correlated with radioactivity results. From the observations, the weight of the magnetic minerals is an index to identify the sediments of low or high radiological risk.

Keywords: river sediments; Palar River; RHP rate; radioactive heat production; ELCR; excess lifetime cancer risk; quartz; magnetic susceptibility; natural radioactivity; hazardous index; India; absorbed dose rate; radium equivalent concentration; feldspar; radiological risks; low radiation.

DOI: 10.1504/IJLR.2015.071761

International Journal of Low Radiation, 2015 Vol.10 No.1, pp.14 - 33

Received: 27 Nov 2014
Accepted: 08 Jun 2015
Published online: 17 Sep 2015 *