This paper reports the measurements of indoor radon and thoron concentrations in selected Northern Indian dwellings (differing in ventilation rate). These were carried out using single entry pin hole based radon thoron dosimeters. In order to correlate the indoor levels with source term, the radon and thoron exhalation rates from soil samples collected from the same dwellings were also measured. Active measurement techniques with scintillation radon monitor and scintillation thoron monitor were used for exhalation measurements from soil sample. For thoron exhalation rate measurements, a small volume chamber was used. The indoor radon and thoron concentration in different rooms varied from 14 to 97 Bq/m3 and 23 to 189 Bq/m3, respectively. The radon mass exhalation and thoron mass emanation rates of soil samples varied from 28.2 to 91.2 mBq/kg/h and 3.42 to 12.1 mBq/kg/h, respectively. A weak correlation was found between indoor concentration and soil exhalation rates for these dwellings. Indoor radon concentrations from various rooms in the dwellings were lower than the limit (100 Bq/m3) recommended by WHO (2009).
UNSCEAR: United Nations Scientific Committee on the Effects of Atomic Radiation. Ionizing radiation: exposure due to natural radiation sources, New York: UNSCEAR, 2000.
2.
ZeebHShannounF. WHO handbook on indoor radon – a public health perspective, Geneva: World Health Organization, 2009.
3.
DentonGRWNamaziS. Indoor radon levels and lung cancer incidence on guam. Proc Environ Sc2013; 18: 157–166.
4.
SahooBKSapraBKGawareJJKanseSDMayyaYS. A model to predict radon exhalation from walls to indoor air based on the exhalation from building material samples. Sci Total Environ2011; 409: 2635–2641.
5.
StoulosSManolopoulouMPapastefanouC. Assessment of natural radiation exposure and radon exhalation from building materials in Greece. J Environ Radioact2003; 69: 225–240.
6.
NazaroffWWNeroAVJr. Radon and its decay products in indoor air, New York: John Wiley and Sons, 1988.
7.
KumarAChauhanRPJoshiMSahooBK. Modeling of indoor radon concentration from radon exhalation rates of building materials and validation through measurement. J Environ Radioact2014; 127: 50–55.
8.
StojanovskaZBossewPTokonamiSZunicZSBochicchioFBoevBRistovaMJanuseskiJ. National survey of indoor thoron concentration in FYR of Macedonia (continental Europe e Balkan region). Radiat Meas2013; 49: 57–66.
9.
SzaboKZJordanGHorváthASzaboC. Mapping the geogenic radon potential: methodology and spatial analysis for central Hungary. J Environ Radioact2014; 129: 107–120.
10.
SahooBKSapraBKKanseSDGawareJJMayyaYS. A new pin-hole discriminated 222Rn / 220Rn passive measurement device with single entry face. Radiat Meas2013; 58: 52–60.
11.
GuptaMChauhanRPGargAKumarSSonakawadeRG. Estimation of natural radioactivity in some soil and sand sample. Indian J Pure Appl Phys2010; 48: 482–486.
12.
ChauhanRPChauhanPPundirAKambhojSBansalVSainiRS. Estimation of dose contribution from 226Ra, 232Th and 40K and radon exhalation rates in soil samples from Shivalik foot hills in India. Radiat Prot Dosim2013; 158: 79–86.
13.
GuptaMChauhanRP. Estimation of low level radiation dose from some building materials using gamma spectroscopy. Indoor Built Environ2011; 21: 465–473.
14.
ChauhanRPKantKSharmaSKChakarvartiSK. Measurement of alpha radioactive air pollutants in flyash brick dwellings. Radiat Meas2003; 36: 533–536.
15.
UjicPCelikovicIKandicAZunicZ. Standardization and difficulties of the thoron exhalation rate measurements using an accumulation chamber. Radiat Meas2008; 43: 1396–1401.
16.
PetropoulosNPAnagnostakisMJSimopoulosSE. Building materials radon exhalation rate: ERRICCA intercomparison exercise results. Sci Total Environ2001; 272: 109–118.
17.
GawareJJSahooBKSapraBKMayyaYS. Development of online radon and thoron monitoring systems for occupational and general environments. BARC Newsletter2011; 318: 45–51.
18.
GawareJJSahooBKSapraBKMayyaYS. Indigenous development and networking of online radon monitors in the underground uranium mine. Radiat Protect Environ2011; 34: 37–40.
19.
ChenJRahmanMMAtiyaIA. Radon exhalation from building materials for decorative use. J Environ Radioact2010; 101: 317–322.
20.
SahooBKNathwaniDEappenKPRamachandranTVGawareJJMayyaYS. Estimation of radon emanation factor in Indian building materials. Radiat Meas2007; 42: 1422–1425.
21.
SharmaNVirkHS. Exhalation rate study of radon/thoron in some building materials. Radiat Meas2001; 34: 467–469.
22.
TuccimeiPMoroniMNorciaD. Simultaneous determination of 222Rn and 220Rn exhalation rates from building materials used in Central Italy with accumulation chambers and a continuous solid state alpha detector: influence of particle size, humidity and precursors concentration. Appl Radiat Isot2006; 64: 254–263.
23.
SahooBKMayyaYS. Two dimensional diffusion theory of trace gas emission into soil chambers for flux measurements. Agric Forest Meteorol2010; 150: 1211–1224.
24.
CsigeISzabóZSzabóC. Experimental technique to measure thoron generation rate of building material samples using RAD7 detector. Radiat Meas2013; 59: 201–204.
25.
SumeshCGKumarAVTripathiRMNairRNPuranikVD. Impact of flow rate on sensitivity of semiconductor type thoron monitor. Radiat Meas2013; 59: 241–245.
26.
MayyaYS. Theory of radon exhalation into accumulators placed at the soil–atmosphere interface. Radiat Prot Dosim2004; 111: 305–318.
27.
Al-MasriMSShwiekani. Radon gas distribution in natural gas processing facilities and workplace air environment. J Environ Radioact2004; 99: 574–580.
28.
SathishLASundareshanSRamachandranTV. Radon and thoron levels in dwellings of Bangalore City, India: a review. Phys Rev Res Int2012; 2: 36–69.
29.
RavishankarRChandrasekaranAVijaygopalPVenkatramanBSenthilkuamrGEswaranPRajalakshmiA. Natural radioactivity in soil samples of Yelagiri Hills, Tamil Nadu, India and the associated radiation hazards. Radiat Phys Chem2012; 81: 1789–1795.
30.
Bala P, Mehra M and Ramola RC. Distribution of natural radioactivity in soil samples and radiological hazards in building material of Una, Himachal Pradesh. J Geochem Exploration 2014. http://dx.doi.org/10.1016/j.gexplo.2014.02.010 (accessed 28 April 2014).
31.
TannerABRadon migration in the ground: a review. In: AdamsJASLowderWM (eds). The natural radiation environment, Chicago, IL: The University of Chicago press, 1964, pp. 161–190.
32.
TannerAB. Radon migration in the ground: a supplementary review – in the natural radiation environment, Springerfiled, VA: National Technical Information Service, 1980, pp. 5–56.
33.
MorkoskaLPhilipsC. Dependence of radon emanation coefficient on radium distribution and internal structure of the materials. Geochim Cosmochim1992; 57: 1782–1797.
34.
GreemanDRoseA. Factors controlling the emanation of radon and thoron in soils of the easthern USA. Chem Geol1995; 129: 1–14.
35.
Kumar A and Chauhan RP. Measurement of indoor radon–thoron concentration and radon soil gas in some North Indian dwellings. J Geochem Exploration 2014. http://dx.doi.org/10.1016/j.gexplo.2014.04.006 (accessed 30 April 2014).
36.
Mehta V, Kumar A, Singh SP, Chauhan RP and Mudahar GS. Measurement of indoor radon, thoron and their progeny levels in dwellings of Union Territory Chandigarh, India: correlation with radon exhalation rates. Indoor Built Environ 2014. DOI: 10.1177/1420326X14535792 (accessed 27 May 2014).
