Preliminary indoor thoron measurements in high radiation background area of southeastern coastal Orissa, India

Abstract

This paper presents the preliminary results of radon and thoron measurements in the houses of Chhatrapur area of southeastern coast of Orissa, India. This area is one of the high radiation background radiation areas in India, which consists of monazite sand as the source of thoron. Both active and passive methods were employed for the measurements. Radon and thoron concentrations were measured in the houses of Chhatrapur area using twin cup radon dosemeters, RAD7 and radon-thoron discriminative detector (Raduet). Thoron progeny concentration was also measured in the houses using deposition rate measurements. Radon and thoron concentrations in the houses of study area were found to vary from 8 to 47 Bq m(-3) and the below detection level to 77 Bq m(-3), respectively. While thoron progeny concentration in these houses ranges between 0.17 and 4.24 Bq m(-3), preliminary investigation shows that the thoron concentration is higher than radon concentration in the houses of the study area. The thoron progeny concentration was found to be comparatively higher, which forms a base for further study in the area. The comparison between the results of various techniques is presented in this paper.

Long-term measurements of residential radon, thoron, and thoron progeny concentrations around the Chhatrapur placer deposit, a high background radiation area in Odisha, India

“…The thickness of the films was adjusted to absorb the energy of alpha particles from radon, thoron and their progenies except for 212 Po (8.78 MeV). Since the Raduet and thoron progeny deposition detector are inexpensive and easy to use, they are often used in a large-scale survey (e.g., Chen et al, 2012;Janik et al, 2013;Kudo et al, 2015;McLaughlin et al, 2011;Ramola et al, 2010Ramola et al, , 2012.…”

“…In this area, surveys on radon and thoron concentrations in dwellings were carried out and they revealed that thoron concentration is higher than radon concentration (e.g., Ramola et al, 2010Ramola et al, , 2012Sulekha Rao and Sengupta, 2010). Sulekha Rao and Sengupta (2010) also attempted to calculate the dose due to inhalation of thoron (including its progeny) based on measurements of thoron gas.…”

“…However, this evaluation may have a large uncertainty because concentration of thoron gas is not necessarily representative of its progeny concentration (Tokonami, 2010;Yonehara et al, 2005). Moreover, although Ramola et al (2010) reported the thoron progeny concentration, their measurement had been conducted for only three months which may be insufficient to evaluate annual dose.…”

Comparative analysis of radon, thoron and thoron progeny concentration measurements

“…In the past, Rn studies were more common than those of Tn, but recent studies in Serbian [1–3], Chinese [4, 5], Indian [6] Canadian [7–9], Japanese [10], Korean [11, 12], Hungarian [13], Slovenian [14], Irish [15, 16] and USA [17] dwellings have show that Tn can be a significant contributor to the radiation exposure. The contributions of Rn and Tn and its progeny (TnP) to radiation exposure are quite different.…”

Low-dose Radiation Induces Antitumor Effects and Erythrocyte System Hormesis

“…Since the hypothesis of hormesis was reported in 1982 by Luckey, people have had some new understand on this problem Ramola et al, 2010Ramola et al, , 2012Walsh & Kaiser, 2011;Rautela et al, 2012). The epidemiology showed that the incidence of tumor was not increased in those people who were workers in A-test place, victims receiving low dose radiation in explosion of atom-bomb and atomic accidents, medical staff in radiology department and patients receiving radiation treatment.…”