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To appear in: Applied Radiation and Isotopes Received date: 9 January 2015 Revised date: 3 April 2015 Accepted date: 9 April 2015 Cite this article as: Asha Rani, Sudhir Mittal, Rohit Mehra and R C Ramola, Assessment of natural Radionuclides in the soil samples from Marwar region of Rajasthan, India, Applied Radiation and Isotopes, http://dx.doi.org/10.1016/j.apradiso.2015.04.003 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Assessment of Natural Radionuclides in the soil samples from Marwar region of Rajasthan, India Asha Rani1, *Sudhir Mittal2, Rohit Mehra3, R C Ramola4 1

Department of Applied Science, Ferozepur College of Engineering and Technology, Farozshah,

Ferozepur-142052, Punjab, India 2

Department of Applied Sciences, Punjab Technical University, Jalandhar-144601, Punjab, India

3

Department of Physics, Dr. B.R.Ambedkar National Institute of Technology, Jalandhar-144011,

India 4

Department of Physics, HNB Garhwal University, Badshahi Thaul Campus, Tehri Garwal-249

199, India *E-mail: [email protected] Keywords: Gamma ray spectrometry, Raeq activity, Annual effective dose, Internal hazard index, External hazard index. Abstract In the present investigation, 226Ra, 232Th and 40K analysis has been carried out in the soil samples collected from different locations of Jodhpur and Nagaur districts of Northern Rajasthan, India using gamma ray spectroscopy. The measured activity concentration ranges from 13±8 to 36±9 Bq kg-1, 40±9 to 71±11 Bq kg-1 and 294±125 to 781±159 Bq kg-1 with the mean value of 24±9 Bq kg-1, 55±11 Bq kg-1and 549±141 Bq kg-1 for

226

Ra,

232

Th and

40

K, respectively. The radium

equivalent activity of all the soil samples ranges from 114 to 157 Bq kg-1 with an average value of 141 Bq kg-1, which is lower than the safe limit 370 Bq kg-1 as set by the Organization for

Economic Cooperation and Development. The total absorbed dose of all the investigated samples varies from 56 to 77 nGy h-1 with an average value of 68 nGy h-1. The overall annual effective dose ranges from 0.34 to 0.47 mSv with the average value of 0.41 mSv. The corresponding values of external and internal hazard index of all the soil samples ranges from 0.32 to 0.43 and 0.37 to 0.53 with an average value of 0.39 and 0.45 respectively. It was observed that the soil of Jodhpur and Nagaur districts is suitable for construction purpose without posing any health hazard.

1. Introduction The natural radionuclides are usually found in soil, rocks, plants, water and air (Ibrahiem et al., 1993; Malance et al., 1996). The information about these natural radionuclides concentration levels and their effect on the environment is of great importance in several fields of science and engineering. Therefore it is useful to know the distribution of source rock materials containing higher levels of natural radionuclides in soil. The naturally occurring radionuclides present in soil include

226

Ra,

232

Th and

40

K (Rani et al., 2005; Menon et al., 1982). Gamma radiation

emitted from these naturally occurring radionuclides, represents the main source of irradiation on human body and contribute to the total absorbed dose via. Ingestion, inhalation and external irradiation (Steinhausler, 1992). The presence of radionuclides above a certain permissible level in soil becomes a health hazard. Their exposure is associated with the risk of leukemia and certain other cancers such as melanoma, cancers of kidney and prostate (Henshaw et al., 1972). As a consequence the soil radioactivity is usually important for the purpose of establishing base line data for further radiation impact assessment, radiation protection and exploration (Ramli et al., 2005).

The concentration of natural radionuclides in soil varies from one region to another region in the World. Recently it has been reported that the activity concentration of natural radionuclides found in the soil samples of Hanumangarh, Sriganganagar, Churu and Sikar districts of Rajasthan was higher than the permissible limit (Duggal et al., 2013). Jodhpur and Nagaur are adjoining districts to the reported areas. Hence the study on the measurement of activity concentration of natural radionuclides in these adjoining districts assumes significance. Such a study will be helpful in determining whether the soil of these adjoining regions can be used for construction purpose without posing any health hazard. However literature survey shows that no attempt has been made towards the measurement of activity concentration of natural radionuclides in the Jodhpur and Nagaur districts. In the present study the activity concentration of natural radionuclides

226

Ra,

232

Th and

40

K in the soil samples from Jodhpur and Nagaur

districts of Rajasthan, India has been investigated.

2. Geology of the area Rajasthan is located in North West of India. It lies between 23°30´ and 30°11´ north latitude and 69°29´ and 78°17´ east longitude. Figure 1 shows the geographic location of Rajasthan in India, as well as the location of the sampling sites. Jodhpur district the study area in the present work is located in western part of Rajasthan and is bounded by 26°00´ to 27°37´ latitude and 72°55´ to 73°55´ longitude. It shares common border with five districts namely Bikaner, Jaisalmer in north and northwest, Banner and Pali in South West and South East and Nagaur in East-North East. The area is covered by Hillocks rocks, Luni-Jawa Plains, Sukri and Jojri rivers. The rocks of the area contain sandstone, limestone and granite. The major mineral occurrence of the district is Jasper, Dolomite and Ball clay. The

geological configuration of Jodhpur district is represented by rocks ranging from Pre-Cambrian to recent in age. The lithounits consist of igneous, sedimentary and metamorphic units. Nagaur district falls almost in the central part of Rajasthan. The district is bounded by the latitudes 26°02´ to 27°37´ and longitudes 73°05´ to 75°24´. This area comprises a part of great Thar desert and a large part of it is covered by windblown sand. The boundary of this region is shared by seven districts of Rajasthan viz.-Jaipur, Ajmer, Pali, Jodhpur, Bikaner, Churu and Sikar. This district is well known over the world owing to the presence of Makrana marble. It is covered by the Delhi super group rocks, Erinpura granite, Malani igneous suite, Marwar super group rocks and Jogira fuller's Earth/Kuchera Khajuwana series rocks. The lake that contains the highest content of salt i.e Sambhar lake is located in Nagaur District. The minerals which occur in this region are limestone, lignite, gypsum and marble. The type of soil found in these two districts is clay, clay loam, sandy loam and sandy soil. 3. Materials and methods 3.1 Sample Collection and Preparation In order to measure the activity concentration of natural radionuclides the soil samples were collected from 20 different locations of Jodhpur and Nagaur districts of Marwar region of Rajasthan on random basis. The samples were collected at a depth equal to or greater than 0.75m from the ground level so as to get the natural soil. The organic material, pebbles, roots and vegetables presented in the soil were removed manually. All these soil samples were crushed in to fine powder by using mortar pestle. Thereafter the samples were dried in an electric oven at 110°C and sieved through 150 µm sieve. Each dried sample of 250g was sealed in an airtight PVC container of 250 ml capacity and kept isolated for about 4weeks, so as to ensure radioactive

equilibrium among the daughter product of radon (226Ra), thoron (232Th) and their short lived decay products. 3.2 Gamma ray spectrometry The activity concentration of natural radionuclides

226

Ra,

232

Th and

40

K were measured in soil

samples by using a gamma ray spectrometer. The prepared samples were placed in a shielded gamma ray spectrometry unit for a counting time of 3hours in order to get accurate results. The measurement of natural radionuclides in soil samples was carried out by using NaI(Tl) gamma radiation detector of size 63mm × 63mm with a multichannel analyzer. The activity concentration of

40

K was determined from the 1460 keV photo peak; the activity of

the 1764 keV gamma line of

214

Bi; and that of

232

226

Ra from

Th from the 2610 keV gamma line of

208

Tl

(Henshaw et al., 1972). This spectral analysis was performed with the aid of computer software SPTR-ATC (AT-1315). The peak energies of gamma spectra were measured with respect to the 662 keV photo peak of137Cs. The detector was calibrated with standard sources of 238U, 232Th and 40

K; these sources have been selected as per IAEA guidelines (2003). The detection limits are 3,

3 and 30 Bq kg-1 for

226

Ra, 232Th and

40

K respectively. The activity concentrations of the soil

samples were calculated from the intensity of each line in the spectrum, taking into consideration the mass, the geometry of the samples, the counting time and the efficiency of detector. 3.3 Radium equivalent activity It is well known that natural radionuclides

226

Ra,

232

Th and 40K are not uniformly distributed in

soil. The non-uniform distribution of these naturally occurring radionuclides is due to nonequilibrium between

226

Ra and its decay products. For uniformity in exposure estimates, the

concentration of radionuclides have been defined in terms of Radium equivalent activity (Raeq)

having units Bq kg-1. This permits the comparison of specific activity of materials containing different amounts of 226Ra, 232Th and 40K by the following relation (Yu et al., 1992): Raeq= CRa + 1.43 CTh + 0.07 CK,

(1)

where CRa, CTh and CK are activity concentrations of

226

Ra,

232

Th and

40

K in Bq kg-1,

respectively. While defining Raeq activity, it has been assumed that 370 Bq kg-1 of

226

Ra or 259

Bq kg-1 of 232Th or 4810 Bq kg-1 of 40K produce the same dose rate. 3.4 Calculation of air-absorbed dose rate For a uniform distribution of radionuclides 226Ra, 232Th and 40K, the absorbed dose rate in air at a height of 1m above the ground surface was calculated by using a conversion factor of 0.0414 nGy h-1/Bq kg-1 for

40

K, 0.461 nGy h-1/Bq kg-1 for

226

Ra and 0.623 nGy h-1/Bq kg-1 for

232

Th,

respectively. The conversion factors used to calculate the absorbed dose rate in air per unit activity concentration in Bq kg-1 are given as UNSCEAR (2000): D (nGy/h) = 0.461 CRa+ 0.623 CTh + 0.0414 CK,

(2)

where CRa ,CTh and CK are the activity concentration of Radium, Thorium and Potassium in the sample. 3.5 Calculation of annual effective dose In order to calculate the annual effective dose equivalent UNSCEAR gives a conversion factor of 0.7 Sv/Gy, to convert the absorbed dose rate to the effective does equivalent with indoor and outdoor occupancy of 80% and 20%, respectively is given by UNSCEAR (1993). The annual effective dose rates are determined by the equation: Indoor (mSv) = (Absorbed Dose) nGy/h * 8760 * 0.8 *0.7 Sv/Gy * 10-6,

(3)

Outdoor (mSv) = (Absorbed Dose) nGy/h * 8760 * 0.2 *0.7 Sv/Gy * 10-6,

(4)

3.6 External and internal hazard index (Hex and Hin) As local soil of the area is used for the construction of houses. Therefore the soils will contribute to the external gamma dose rates in these houses. The external hazard index (Hex) is calculated by the following relation (Beretka et al., 1985): Hex = CRa/370 + CTh/259 + CK/4810, where CRa, CTh and CK are the activity concentration of

(5) 226

Ra,

232

Th and

40

K in Bq kg-1,

respectively. When the value of Hex is less than unity then the radiation received by occupants will be less than 1.5 mGy y-1. The maximum value of Hex equal to unity corresponds to upper limit of Raeq (370 Bq/kg). The internal exposure to 222Rn and its radioactive descendant is controlled by the internal hazard (Hin), which is calculated by the relation (Quindos et al., 1987): Hin = CRa/185 + CTh/259 + CK/4810,

(6)

For safe use of soil Hin should be less than 1.

4. Results and discussion The measured values of natural radioactivity concentration for

226

Ra,

232

Th and

40

K from

different location of Jodhpur and Nagaur districts of Rajasthan, India are given in table 1. Only one measurement was taken for each sample and activity concentration of natural radionuclides 226

Ra,

232

Th and

40

K was simultaneously measured. The worldwide average activity

concentrations for 226Ra, 232Th and 40K reported by UNSCEAR (2000) are 35 Bq kg-1, 30 Bq kg-

1

and 400 Bq kg-1 respectively. The drinking water samples from the same area are also being

analyzed for radioactivity and the results of water samples will be further analyzed to evaluate the internal exposure from water samples. From table 1 it is clear that the activity concentration of 226Ra, 232Th and 40K in the soil samples ranges from 13±8 to 36±9 Bq kg-1, 40±9 to 71±11 Bq kg-1 and 294±125 to 781±159 Bq kg-1 with over all mean value of 24±9 Bq kg-1, 55±11 Bq kg-1and 549±141 Bq kg-1 respectively. The range of activity concentration for 232Th and 40K in soil of these areas are higher where as for 226Ra is lower than the worldwide figures reported by UNSCEAR (2000). The variation in the concentrations of these naturally occurring radionuclides depends on geological condition such as formation of rocks and transport process (Choubey et al., 1999). The high activity of due to the use of fertilizer rich on potassium. Since

40

40

K is

K is only one of the natural isotopes of

potassium. In table 2, a comparison of activity concentration of 226Ra, 232Th and 40K from different locations is presented. From which it can be seen that the activity concentration for the soil samples of Bangladesh (Nine Southern districts), Pakistan (Lahore) and Brazil (Rio Grande do Norte) is in close agreement with the present work. However for Nigeria, Uttrakhand and Malwa region of Punjab the activity concentration is higher where for Cyprus and Canada the activity concentration is lower than the reported values in the present investigation. In the present study the activity concentration of

226

Ra and

232

Th in the soil samples is lower whereas for

40

K is

higher than the previous reported values of Rajasthan as tabulated in table 2. The radium equivalent activity (Req) of the soil samples tabulated in table 1 ranges from 114 to 157 Bq kg-1 with the average value of 141 Bq kg-1. This value is less than 370 Bq kg-1 which is accepted for safe use as recommended by the OEDC (1979). No uniform trend in the variation of terrestrial radioactivity has been found from the studied area.

The air absorbed dose rate calculated from activity concentration is tabulated in table 3. From which it can be seen that air absorbed dose rate ranges between 6 to 17 nGy h-1, 25 to 41 nGy h-1 and 12 to 30 nGy h-1 with the mean value of 11 nGy h-1, 34 nGy h-1, 23 nGy h-1 for 226Ra, 232Th and 40K, respectively. The total absorbed dose rate varies from 56 to 77 nGy h-1 with an average value of 68 nGy h-1, which is found to be less than the Global and Indian average value of 86 nGy h-1 and 90 nGy h-1 respectively as reported by UNSCEAR (2000). The annual effective indoor and outdoor gamma dose rates calculated in the study area ranges from 0.27 to 0.38 mSv and 0.07 to 0.09 mSv with respective mean values of 0.33 mSv and 0.82 mSv. The total annual effective dose rate ranges from 0.34 to 0.47 mSv with an average value of 0.41 mSv. The worldwide average annual effective dose rate is approximately 0.5 mSv. From table 3 it is clear that in the present soil samples the average annual effective dose rate is less than worldwide annual average value. From the measured activity concentration of

226

Ra,

232

Th and

40

K, the health hazard index was

calculated to estimate external and internal radiation exposure. The calculated values of external (Hex) and internal hazard (Hex) indices lie in the range from 0.32 to 0.43 and 0.37 to 0.53 with the average value of 0.39 and 0.45 respectively. These values are less than unity, according to the Radiation Protection 112 report given by European commission, (1999). Hence the soil from these regions is safe and can be used as a construction material without any radiological hazard to the population. 5. Conclusion 1. The measured activity concentrations of

232

Th and

40

K in soil samples of Marwar region of

Rajasthan are higher than the World figures reported in UNSCEAR (2000). However the concentrations for 226Ra are found to be lower than the World figures.

2. The total absorbed dose rate determined in the soil samples of the studied area is less than the recommended safe limits reported by UNSCEAR report. 3. The indoor and outdoor effective dose rates due to natural radioactivity of soil samples are found to be lower than the value recommended by worldwide average annual effective dose. 4. The results obtained from the external and internal hazard for the studied soil samples are lower than unity which is safe according to Radiation Protection 112 (European Commission, 1999) report. 5. The soil of selected regions of Jodhpur and Nagaur districts can be used as a construction material without posing any significant radiological threat to the inhabitants.

Acknowledgment The authors are highly thankful to the resident of the study area for their cooperation during the fieldwork, and Department of Physics, H.N.B. Garhwal University, Badshahi Thaul Campus, Tehri Garhwal, India for their support in providing the necessary equipments for gamma-ray spectrometry. References Akhtar, N., Tufail, M., Ashraf, M., Iqbal, M., 2005. Measurement of environment radioactivity for estimation of radon exposure from saline soil of Lahore, Pakistan. Radiation Measurement. 39, 11-14. Arogunjo, A. M., Farai, I. P., Fuwape, A., 2004. Dose rate assessment of terrestrial gamma radiation in the Delta region of Nigeria. Radiation Protection Dosimetry. 108, 73-77.

Beretka, J., Mathew, P. J., 1985. Natural radioactivity of Australian building materials, industrial water and by-products. Health Physics. 48, 87-95. Choubey, V. M., Bist, K. S., Saini, N.K., Ramola, R. C., 1999. Relation between soil-gas radon variation and different lithotectonic units, Garhwal Himalaya, India. Appl. Radiat. Isot. 51, 587592. Chowdhury, M. I., Kamal, M., Alam, M. N., Yeasmin, S., Mostafa, M. N., 2006. Distribution of naturally occurring radionuclides in soils of the Southern districts of Bangladesh. Radiat. Prot. Dos. 118 (1), 126-130. Duggal, V., Rani, A., Mehra, R., Ramola, R. C., 2013. Assessment of natural radioactivity levels and associated dose rate in soil samples from Northern Rajasthan,India. Radiation Protection Dosimetry 158 (2). pp 1-6. Doi: 10.1093/ rpd / nct199. EC (European Commission), 1999. Radiation protection 112. Radiological protection principles concerning the natural radioactivity of building materials. Henshaw, D. L., Eotough, J. B., Richarbson, J.B., 1972. Radon as a causative factor in induction of myeloid leukaemia other cancer. Lancet. 355, 1008-1015. IAEA (International Atomic Energy Agency), 2003. Guidelines for radioelement mapping using gamma ray spectrometry data. Vienna, Austria. (http://www-pub.iaea.org/mtcd/publications/pdf/te_1363_web.pdf). Ibrahiem, N. M., Abdel-Ghani, A. H., Shawky, S.M., Ashraf, E.M., Farouk, M.A., 1993. Radiological Study on Soils, Foodstuff and Fertilizers in the Alexandria Region, Egypt. Health Phys. 64, 620-627.

Kiss, J. J., De Jong, E., Bettany, J. R., 1988. The distribution of natural radionuclides in native soils of Southern Saskatchewan, Canada. Journal of Environment Quality. 17, 437-445. Malanca, A., Gaidolif, L., Pessina, V., Dallara, G., 1996. Distribution of 226Ra,

232

Th and 40K in

soils of Rio Grande do Norte, Brazil. Journal of Environment Radioact. 30, 55-67. Mehra, R., Singh, S., Singh, K., Sonkawade, R., 2007.

226

Ra,

232

Th and

40

K analysis in soil

samples from some areas of Malwa region, Punjab, India using gamma ray spectrometry. Environ. Monit. Assess. 134, 333-342. Menon, M. R., Mishra, U. C., Lalit, B. Y., Shukla, V. K., Ramchandran T. V., 1982. Uranium , thorium, potassium in indian rocks and ores. Proceeding of the Indian Academy of Sciences (Earth,Platenary sciences). 91, 127-136. Nageswara Rao, M. V., Bhati, S. S., Rama Seshu, P., Reddy, A. R., 1996. Natural Radioactivity in Soil and Radiation Levels of Rajasthan. Radiation Protection Dosimetry. 63(3), 207-216. OECD (Organization for Economic Cooperation and Development), 1979. Exposure to radiation from the natural radioactivity in building materials. Reported by a group of experts of OECD Nuclear Energy Agency, Paris, France. Quindos, L. S., Fernandez, P. L., Soto, J., 1987. Building materials as source of exposure in houses. Indoor Air 87. 2, 365. Quindos, L. S., Fernandez, P. L., Soto, J., Rodenas, C., Gomez, J., 1994. Natural radioactivity in Spanish soil. Health Phy. 66, 194-200. Ramli, A. T., Wahab, A., Hussein, M. A., Khalik Wood, A., 2005. Environmental 232

238

U and

Th concentration measurements in an area of high level natural background radiation at

Palong, Johor, Malaysia. J. Environ. Radioactivity. 80, 287-304.

Ramola, R. C., Gusain, G. S., Badoni, M., Prasad, Y., Prasad, G., Ramachandran, T. V., 2008. 226

Ra, 232Th and 40K contents in soil samples from Garhwal Himalayas, India and its radiological

implications. J. Radiol. Prot. 28, 379-385. Rani, A., Singh, S., 2005. Natural radioactivity levels in soil samples from some areas of Himachal Pradesh, India using γ-ray spectrometry. Atmos. Environ. 39, 6306-6314. Steinhausler, F., 1992. The Natural radiation environment: Future Perspective. Radiation Protection Dosimetry. 45: 1/4, 19-23. Tzortzis, M., Svoukis, E., Tsertos, H., 2004. A comprehensive study of natural gamma radioactivity levels and associated dose rates from surface soils in Cyprus. Radiation Protection Dosimetry Journal. 109, 217-224. UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiation), 2000. Sources and effects of ionizing radiations, United Nations, New York. UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiation), 1993. Sources and effects of ionizing radiations. United Nations, New York. Yu, K. N., Guan, Z. J., Stoks, M. J., Young, E. C., 1992. The assessment of natural radiation dose committed to the Hong Kong people. J. Environ. Radiaoact. 17, 31-48.

FIGURE CAPTIONS Figure 1. The map showing samples locations in Northern Rajasthan

TABLE CAPTIONS

Table1. The values 226Ra, 232Th and 40K activity concentration using gamma-ray spectrometry and Raeq activity in soil samples of Jodhpur and Nagaur districts of Northern Rajasthan. Sr. No.

Sample

Radium

Thorium

Potassium

Radium

Location

Concentration

Concentration

Concentration

Equivalent

(Village)

in soil

in soil

in soil

Activity

CRadium (Bq kg-1)

CThorium (Bq kg-1)

CPotassium (Bq kg-1 )

Raeq (Bq kg-1)

Jodhpur 1

Sherguarh

25±8

50±10

609±150

139

2

Kvinda

21±8

45±10

718±147

136

3

Ossian

25±8

53±10

781±159

155

4

Tinwari

26±9

59±11

560±142

150

5

Mathania

25±9

66±11

525±135

157

6

Basni(Jodhpur)

36±9

57±11

551±141

156

7

Kakani

18±8

40±9

555±137

114

8

Dhangeavas

25±9

58±11

672±151

156

9

Pipar City

13±8

42±9

703±145

122

10

Bilada

21±9

51±10

595±152

136

11

Kuchera

31±9

61±11

402±131

146

12

Gogelave

23±9

60±11

475±143

142

13

Nagaur

30±9

66±11

452±134

156

14

Mundawa

23±9

71±11

294±125

145

Nagaur

25

Mehrta Road

21±9

49±10

478±134

125

16

Somana

20±9

50±10

496±128

126

17

Ladnun

21±9

59±11

549±144

144

18

Didwana

24±9

55±10

534±140

140

19

Makrana

21±9

49±10

622±146

135

20

Nawa City

27±9

53±10

405±128

131

13±8 - 36±9

40±9 - 71±11

294±125 -

114 – 157

Range

781±159 Average

24±9

55±11

549±141

141

Table 2. Comparison of natural radioactivity levels in soil samples under investigation with those in other countries. Activity concentration (Bq kg-1) Region

Reference 226

Ra

232

Th

40

K

Northern Rajasthan (Jodhpur and

294±125-

13±8-36±9

40±9-71±11

42

81

833

25.8

49.2

561.6

Nagaur Districts),

781±159

Present Work

India Bangladesh (Nine Southern

Chowdhury et al. (2006)

districts) Pakistan (Lahore)

Akhtar et al. (2005)

Spain

39

41

578

Quindos et al. (1994)

29.2

47.8

704

Malanca et al. (1996)

Cyprus

7.1

5

104.6

Tzortzis et al. (2004)

Canada

19

8

480

Kiss, J. et al. (1988)

9.2±0.7 -

18.4±0.4 -

20.1±4.3 -

82.3±2.4

109±9.3

943.1±5.3

Brazil (Rio Grande do Norte)

Nigeria

BDL -

Uttrakhand, India

Malwa region of Punjab, India

9±6 – 384±53

131±18

18.37 - 53.11

57.28 - 148.28

30 - 78

43 - 106

Rajasthan, India

Arogunjo et al. (2004)

471±96 -

Ramola R.C. et al.

1406±175

(2008)

211.13 413.27

50 -137

Mehra et al. (2007)

Nageswara Rao M.V et al. (1996)

Table 3. Air-absorbed dose rates and annual effective dose at various locations in Jodhpur and Nagaur districts of Northern region of Rajasthan Sr.

Absorbed dose (nGy h-1)

Sample

Annual effective

Location

Hazard Indices

dose (mSv)

no.

Hex (Village)

226

Ra

232

Th

40

Hin

Indoor Outdoor

K

Total

Jodhpur 1

Sherguarh

12

31

25

68

0.33

0.08

0.39

0.45

2

Kvinda

10

28

30

68

0.33

0.08

0.38

0.44

3

Ossian

12

33

32

77

0.38

0.09

0.43

0.50

4

Tinwari

12

37

23

72

0.35

0.09

0.41

0.48

5

Mathania

12

41

22

75

0.34

0.09

0.43

0.50

6

Basni(Jodhpur)

17

36

23

76

0.37

0.09

0.43

0.53

7

Kakani

08

25

23

56

0.27

0.07

0.32

0.37

8

Dhangeavas

12

36

28

76

0.37

0.09

0.43

0.50

9

Pipar City

06

26

29

61

0.30

0.07

0.34

0.38

10

Bilada

10

32

25

67

0.33

0.08

0.38

0.43

11

Kuchera

14

38

17

69

0.34

0.08

0.40

0.49

12

Gogelave

11

37

20

68

0.33

0.08

0.39

0.45

13

Nagaur

14

41

19

74

0.36

0.09

0.43

0.51

14

Mundawa

11

44

12

67

0.33

0.08

0.40

0.46

15

Merta Road

10

31

20

61

0.30

0.07

0.35

0.40

16

Somana

09

31

21

61

0.30

0.07

0.35

0.40

17

Ladnun

10

37

23

70

0.34

0.09

0.40

0.46

18

Didwana

11

34

22

67

0.32

0.08

0.39

0.45

19

Makrana

10

31

26

67

0.33

0.08

0.38

0.43

Nagaur

20

Nawa City

12

33

17

62

0.30

0.08

0.36

HIGHLIGHTS    

Natural radionuclides were studied in soil samples of Jodhpur and Nagaur districts. All the samples were characterized by using NaI(Tl) Gamma ray spectrometry. External and internal hazard for the studied soil samples were within safe limit. The soil of studied area can be used as a construction material.

0.43

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