Available online at www.sciencedirect.com Radiation Measurements 36 (2003) 363–366 www.elsevier.com/locate/radmeas Study of uranium, radium and radon exhalation rate in soil samples from some areas of Kangra district, Himachal Pradesh, India using solid-state nuclear track detectors D.K. Sharma, Ajay Kumar, Mukesh Kumar, Surinder Singh ∗ Department of Physics, Guru Nanak Dev University, Amritsar 143 005, India Received 21 October 2002; received in revised form 26 February 2003; accepted 29 April 2003 Abstract LR-115 plastic track detectors have been used for the measurement of radon exhalation rate and radium concentration in soil samples collected from some villages of Kangra district, Himachal Pradesh, India. Uranium concentration has also been determined in these soil samples using ssion track technique. Radium concentration in soil samples has been found to vary from 11.54 to 26:71 Bq Kg -1 , whereas uranium concentration varies from 0.75 to 2:06 ppm. The radon exhalation rate in these samples has been found to vary from 15.16 to 35:11 mBq Kg -1 h -1 (502.12 to 1162:64 mBq m -2 h -1 ). c  2003 Elsevier Ltd. All rights reserved. Keywords: Uranium; Radium; Radon exhalation; Track detector 1. Introduction Uranium, the heaviest radioactive toxic element is found in almost all types of soils, rocks, sands and water. Uranium is the ultimate source of 226 Ra and 222 Rn. Radon isotopes are decay products of radium in the uranium decay series. As an inert gas radon can diuse through the soil and enter the atmosphere. Henshaw et al. (1990) has claimed that indoor radon exposure is associated with the risk of leukaemia and certain other cancers, such as malenoma and cancers of the kidney and prostate. If uranium-rich material lies close to the surface of earth there can be high radon exposure hazards (Archer et al., 1973; Sevc et al., 1976; UNSCEAR, 1993). Radium is a solid radioactive element under ordinary conditions of temperature and pressure. It decays to radon emitting -particles followed by -radiations. It is the con- centration of radium which governs how many radon atoms are formed. How many of the produced radon atoms leave, i.e. emanate from the mineral grain or matter and enter the ∗ Corresponding author. Tel.: +91-183-225-7007; fax: +91- 183-225-8820. E-mail address: surinder51@yahoo.com (S. Singh). pore spaces, depends on; where the radium atoms are situ- ated in the grain, the texture and size of the grain, the per- meability of the grains, temperature and pressure (Fleischer, 1980, 1982; Tanner, 1980; Anderson et al., 1983). The mea- surements of radon thus necessitate the need for uranium and radium estimation in the parent source for public health risk measurements. Uranium, radium and radon exhalation studies have been carried out in Hamirpur, Kullu and Una districts of Himachal Pradesh (Kumar et al., 2001; Singh et al., 1998, 2001a, b). In the present investigation, the survey was carried out rst time for the measurements of uranium, radium and radon exhalation rate from some soil samples of Kangra district, Himachal Pradesh. 2. Experimental methods To understand the migration and exhalation of radon in naturally occurring soils of dierent areas of district Kan- gra, Himachal Pradesh, India, soil samples were collected from 18 dierent villages covering an area of approximately 60 km 2 . Geologically district Kangra lies between 31 ◦ 40 ′ – 32 ◦ 25 ′ east longitudes and 70 ◦ 35 ′ –77 ◦ 5 ′ north latitudes. 1350-4487/03/$-see front matter c  2003 Elsevier Ltd. All rights reserved. doi:10.1016/S1350-4487(03)00152-5