Measurements of Indoor Radon Levels in India using Solid State Nuclear Track Detectors: Need for Standardisation

M.C. Subba Ramu; A.N. Shaikh; T.S. Muraleedharan; T.V. Ramachandran

doi:10.14429/dsj.42.4386

M.C. Subba Ramu Environmental Assessment Division. Bhabha Atomic Research Centre,Bombay
A.N. Shaikh Environmental Assessment Division. Bhabha Atomic Research Centre,Bombay
T.S. Muraleedharan Environmental Assessment Division. Bhabha Atomic Research Centre,Bombay
T.V. Ramachandran Environmental Assessment Division. Bhabha Atomic Research Centre,Bombay

DOI: https://doi.org/10.14429/dsj.42.4386

Keywords: Nuclear tracks detectors

Abstract

Solid-state nuclear track detectors are being used to obtain the time integrated concentration levels of indoor radon/thoron and their daughters. This technique is preferred for taking such measurements in dwellings. Such measurements are important as the radiation dose to human beings due to indoor radon constitutes more than 50 per cent of the total dose including that received from the natural sources. Normalisation is necessary to obtain a representative value of the effective dose equivalent to the population. Indoor measurements carried out by several laboratories all over the country show that the indoor radon levels vary from 1.5 to about 2000 Bq m/sup -3/, while the normal level is in the range of 10 to 60 Bq m/sup -3/. It is rather difficult to compare the levels since the exposure conditions, the period of measurements and the calibration techniques used are not standardised. The present paper discusses the measurements of indoor radon in India by various groups and the important problems associated with the standardisation of these measurements. The standardisation procedure and the calibration set-up developed at this laboratory are also presented.

Author Biographies

M.C. Subba Ramu, Environmental Assessment Division. Bhabha Atomic Research Centre,Bombay

Environmental Assessment Division. Bhabha Atomic Research Centre,Bombay

A.N. Shaikh, Environmental Assessment Division. Bhabha Atomic Research Centre,Bombay

Dr AN Shaikh is working as Scientific Officer at Bhabha Atomic Research Centre, Bombay, since 1968. He has worked in the fields of radiation and environmental protection in general ,and radiation standards, air pollution, experimental tobacco carcinogenic analysis, trace elements measurement, neutron activation analysis, x-ray flouresence , radon measurements, and SSNTDs in particular. He has about 50 publications to his credit.

T.S. Muraleedharan, Environmental Assessment Division. Bhabha Atomic Research Centre,Bombay

Environmental Assessment Division. Bhabha Atomic Research Centre,Bombay

T.V. Ramachandran, Environmental Assessment Division. Bhabha Atomic Research Centre,Bombay

Dr TV Ramachandran joined BARC in 1971. He has worked on investigations on fresh fallout debris, and on naturill and fallout radioactivity measurements in soils, building materials, food stuffs and other environmental samples like coal, fly-ash and bottom ash from the thermal power plants for their radioactivit y content using gamma spectrometry. He was associated with the commissioning of the low level counting laboratory for the analysis of very low active samples. He has also participated in the MONEX carried over the ocean as well as in the tenth Indian Antarctic Expedition. He is presently working on the measurement of indoor radiation
levels in dwellings using SSNTD technique for obtaining the national average background indoor radiation level for the country as well as in the separation of radon and thoron measurements. He has standardised the measuring techniques and the methods of measurements for the same . Dr Ramachandran has more than 130 publicat ions to his credit.