Earth Syst Environ (2017) 1:4 DOI 10.1007/s41748-017-0005-y

ORIGINAL ARTICLE

Radioactivity in Building Materials of Pudukkottai Geological Region, Tamil Nadu, India

1 2 3 G. Sankaran Pillai • K. Jeevarenuka • P. Shahul Hameed

Received: 6 February 2017 / Accepted: 10 May 2017 / Published online: 23 May 2017 Ó Springer International Publishing Switzerland 2017

Abstract recorded low Raeq activity. Important radiological param- Background Since Pudukkottai district is naturally eters such as ADRA, Ic and Hin were also calculated. endowed with variety of building material resources such Conclusion The results indicated that there is no elevated as stones, bricks, sand etc. These building materials are radioactivity observed in the studied materials. Therefore, also exported to other district. So analysis of natural it is concluded that the building materials used in the above radioactivity in these building materials is important before mentioned district will not pose any hazard in terms of these put into construction purpose. radioactivity. Purpose WHO reported that indoor radon accumulation from soil and building materials is one of the major factors Keywords Natural radioactivity Á Pudukkottai Á Building for human lung disorders. The main objective of the pre- materials Á Gamma ray spectrometry Á Radium equivalent Á sent study is to measure Naturally Occurring Radioactive Hazard indices Materials (NORM) in building materials of Pudukkottai and to assess the possible radiological risk. Methods A total of 118 samples of building materials have 1 Introduction been investigated for 238U, 232Th, and 40K employing a 300 9 300 NaI(Tl) detector. The soil and rocks of the earth contain substances which

Results The mean Raeq activity of the building materials are naturally radioactive and provide natural radiation maintained the following descending order: Stone exposures. The most important radioactive elements which (299 ± 206 Bq kg-1) [ Soil (145 ± 54 Bq kg-1) Sand occur in the soil and in rocks are the long-lived primordial and Cement (117 ± 28 Bq kg-1) [ Brick (110 ± 26 isotopes of potassium (40K), uranium (238U), and thorium Bq kg-1). The present study identified seven stone quarries (232Th). Since these primordial radionuclides are ubiqui- recorded Raeq higher than the permissible limit tous in the earth crust, therefore, it is impossible to elimi- ([370 Bq kg-1) as set by UNSCEAR, 2008. All other nate radiation exposure altogether, i.e., man cannot building materials mined and used from this district possibly avoid natural radioactivity from the environment. These radioisotopes are occurring in almost all the building materials but in different concentration. Radon contributes about 55% of dose received by man (UNSCEAR 1993). & G. Sankaran Pillai The radiation level due to natural radioactivity is about [email protected] 2.4 mSv year-1 and the estimated worldwide average 226 232 40 1 Radiological Safety Division, Indira Gandhi Centre for activity of Ra, Th, and K in the earth’s crust to be Atomic Research, Kalpakkam 603 102, Tamil Nadu, India 32, 45, and 412 Bq kg-1, respectively (UNSCEAR 2008). 2 Department of Civil Engineering, Shivani Engineering It should be mentioned that human beings have poor College, Tiruchirappalli, 620 009, Tamil Nadu, India radiation resistant behavior (lethal dose = 4 Sv) as com- 3 Environmental Research Center, J.J.College of Engineering pared to other mammals. Therefore, additional exposures and Technology, Tiruchirappalli 620 009, Tamil Nadu, India have to be measured and compared with respect to the 123 4 Page 2 of 12 G. S. Pillai et al. natural radiation exposure. Furthermore, it is important to Radioactivity in commercial building materials of Kerala estimate the potential risk from radiation from the envi- was reported by Pereira et al. (2011). In Tamil Nadu, ronment. Since man spent about 80% in indoor environ- assessment of radioactivity in the building materials is ment, therefore, it is important to measure radioactivity scanty (Ravisankar et al. 2012; Pillai et al. 2016). However, level in building materials of any particular region. In US, data on radioactivity in construction materials of about 16,000–24,000 lung cancer deaths occurred in 2008 Pudukkottai district are totally lacking. Such data are vital among the nonsmokers due to indoor radon (Samet et al. in identifying building materials releasing radioactivity 2009). Kolb and Schismer (1978) reported that the external beyond the permissible limit and use of them for con- gamma radiation exposure was about 33% higher in indoor struction purpose could be avoided. The objective of the as compared to outdoor. Radioactivity of building materials present work is to investigate the natural radioactivity in Taiwan was studied by Chang et al. (1974) and con- distribution in building materials and related radiological cluded that wood frame houses contain very little risk assessment to general public of Pudukkottai. radioactivity and provide some shielding from natural sources in the underlying soil. However, the byproduct from the processing of phosphate rock such as gypsum and 2 Study Area and Sample Collection fly ash from thermal power plant recorded maximum levels of uranium and thorium. Pudukkottai (in tamil kottai means made by rocks) district Radioactivity in soil has been studied in many regions of lies between 78° 250 and 79° 150 east longitude and the world (Faanu et al. 2011; Taskin et al. 2009; Amrani between 9° 500 and 10° 400 of the north latitude. The dis- and Tahtat 2001; Kolo et al. 2012; Hameed et al. 2014; trict covers an area of 4663 km2 and had a population of UNSCEAR 2000) to obtain data on natural radioactivity, 1,618,345 in 2011 with a coastline of 42 km. Thirumayam which can be used to establish if and where local controls fort, Sittanavasal cave paginating, and Narthamalai rock are needed. Such data also enrich the global data bank on cut temples are some notable historical places in this dis- radioactivity that will allow a more accurate estimation of trict. At present, this district is composed of 11 taluks global average values of dosimetric quantities. Hewamanna (Fig. 1). This district is enriched with many stone quarries et al. (2001) studied radioactivity in clay bricks of Sri (Geological survey of India 2006). The stones were directly Lanka, El-Shershaby (2002) in granite of north eastern sampled from 21 stone quarries located in the district. As desert of Egypt, Kovler et al. (2002) measured natural many as 55 virgin soil samples, 22 cultivated soil samples radionuclides in building materials of Isreal, Stoulos et al. and 6 sand samples were collected. Besides these, the man (2003) in Greece, Xinwei (2005) in China, Ademola and made building materials such as bricks (8 no.) and fly ash- Oguneletu (2005) in Nigeria, Anjos et al. (2005) in Brazil based Portland cement (6 no.) were also sampled for the granites, Tsabaris et al. (2007) in albanian sediment, Tur- present study. The bricks are directly sampled from brick than (2008) in Turkey, and radioactivity of some domestic kiln, while commercially available various brands of and imported building materials from south Eastern Europe cement are collected directly from the market. Global by Krstic et al. (2007). Natural radioactivity distribution in Positioning System was used to locate the exact location of bricks of Pakistan, Greece, China, Algeria, Sri Lanka, and sampling stations (Garmin, e-Trex10, USA make). The Kuwait was already reported by Faheem and Mujahid samples were collected based on the IAEA (2004) guid- (2008), Papaefthymiou and Gouseti (2008), Xinwei (2005), ance. The collected building materials were powdered and Amrani and Tahtat (2001), Hewamanna et al. (2001), and sieved and a fine powder with a particle size less than Bou-Rabee and Bem (1996), respectively. Beretka and 2 mm was obtained. Then, the samples were packed and Mathew (1985) measured radioactivity in cements of sealed in an air-tight plastic container and stored for Australia. A similar kind of study was undertaken by Khan 30 days to attain radioactive equilibrium between Ra-226 and Khan (2001) in Pakistan. and its daughter products. These samples were analyzed for Urbanization and quality-of-life style lead to increase natural radioactivity measurement using gamma ray the mining and production of building materials. India is spectrometry. the second largest cement producer (6% share of world cement production) after China. In India, the work on the radioactivity in soil and other building materials is scat- 3 Materials and Methods tered. Mishra and Sadasivan (1971) surveyed natural radioactivity levels in soil. However, Kumar et al. (2003) Gamma ray spectrometry has been used for many years to reported natural radioactivity in construction material. measure the specific radionuclides activity in a given Kumar et al. (1999) also worked on natural radioactivity in sample. This technique is an important tool in the field of building materials and industrial by-products. environmental radioactivity measurements due to its high 123 Radioactivity in Building Materials of Pudukkottai Geological Region, Tamil Nadu, India Page 3 of 12 4

Fig. 1 Sampling stations for stone (St), Soil (So), and cultivated Soil (Cs) in Pudukkottai district resolution, large photo peak efficiency, and it can measure of 40K were noted directly by its own gamma line at different radionuclides in a single spectrum. This technique 1461 keV, whereas 238U and 232Th counts were recorded is working either scintillation [NaI (Tl) detector] or semi- from their daughter radionuclides, namely, 214Bi conductor (HPGe detector) principle. Both these detectors (1764 keV) and 208Tl (2614.6 keV), respectively. The have their own advantages and disadvantages. NaI(Tl) MDA was 2.03 Bq kg-1 for 226Ra, 4.7 Bq kg-1 for 232Th, detectors offer higher detection efficiency and it can be and 18.9 Bq kg-1 for K-40. The confidence level of the operated at room temperature, while HPGe provide supe- obtained result was 95%. rior energy resolution, but it can be performed only at liquid nitrogen temperature. HPGe detector measures the 3.1 Radium Equivalent (Raeq) individual counts of the radionuclides, while NaI(Tl) detector measures the counts by stripping spectrum. For the Radium equivalent (Raeq) activity has been used to express present study, a 300 9 300 NaI(Tl) detector was used for the the total activity of any given environmental matrices -1 measurement of natural radionuclides in building materials. (Beretka and Mathew 1985). The Raeq activity in Bq kg The detailed description of the detector was already doc- is calculated on the assumption 370 Bq kg-1 of 226Ra or umented by Pillai et al. (2015). The background spectrum 259 Bq kg-1 of 232Th or 4810 Bq kg-1 of 40K, which was obtained for 20,000 s. From that spectrum, the Mini- produces the same gamma dose rate: ÀÁ mum Detectable Activity (MDA) was calculated. The À1 Raeq Bq kg ¼ ARa þ 1:43ATh þ 0:077 AK; ð1Þ samples were also counted for 20,000 s. The gross counts

123 4 Page 4 of 12 G. S. Pillai et al.

Table 1 Activity concentrations of primordials in stones of Pudukkottai district

-1 -1 -1 Sampling station Station code Activity concentration (Bq kg )Raeq (Bq kg ) D (nGy h ) Ic Hex 226Ra 232Th 40K

Nartamalai St1 MDA 158 ± 16 1119 ± 39 314 143 1.82 0.85 Irumbali St2 38 ± 10 128 ± 10 468 ± 12 257 115 1.55 0.70 Perambur St3 32 ± 8 160 ± 24 424 ± 28 293 129 1.67 0.79 Kulathur St4 MDA MDA 92 ± 16 12 8 0.11 0.04 Melur St5 MDA 151 ± 15 1085 ± 38 302 137 1.75 0.81 Moodampatti St6 14 ± 4 165 ± 9 831 ± 35 314 141 1.79 0.85 Keeranur St7 MDA 133 ± 7 620 ± 28 239 107 1.32 0.65 Annavasal St8 27 ± 4 282 ± 12 865 ± 32 497 219 2.72 1.34 Rajagiri St9 52 ± 7 347 ± 15 981 ± 35 624 274 3.48 1.68 Kudumiyanmalai St10 15 ± 3 122 ± 9 1068 ± 3 271 125 1.67 0.73 Virallimalai St11 33 ± 5 293 ± 15 1092 ± 8 536 237 3.01 1.45 Nathampannai St12 37 ± 6 327 ± 18 873 ± 6 572 251 3.14 1.55 Iluppur St13 MDA 5 ± 796± 21 17 8 0.12 0.05 Gandarvakottai St14 MDA 32 ± 8 338 ± 36 74 34 0.46 0.20 Ganapathipuram St15 27 ± 3 233 ± 11 486 ± 16 397 173 2.15 1.07 Mudukkulam St16 MDA 281 ± 13 754 ± 7 462 202 2.40 1.25 Ponnamaravathy St17 39 ± 6 387 ± 16 786 ± 23 653 284 3.49 1.76 Kottaiyur St18 MDA 28 ± 9 312 ± 5 66 31 0.41 0.18 Valayampatti St19 6 ± 823± 793± 18 46 20 0.28 0.12 Peranur St20 MDA 157 ± 15 877 ± 6 294 132 1.65 0.79 Pilangudi St21 MDA 13 ± 797± 12 26 13 0.17 0.07 Range B2.03–52 B4.7–387 92–1119 12–653 8–284 0.11–3.49 0.04–1.76 Mean ± SD 16 ± 16 163 ± 121 636 ± 364 299 ± 206 133 ± 90 1.67 ± 1.11 0.8 ± 0.55

226 232 where AU, ATh, and AK are the activities of Ra, Th, The index Ic is correlated with the annual dose rate due to 40 and K, respectively. The safe value of Raeq in building the excess external gamma radiation caused by superficial -1 materials is reported to be less than 370 Bq kg to limit material. Values of index Ic B 2 correspond to a dose rate -1 the annual effective dose to 1 mSv for the general public criterion of 0.3 mSv year , whereas 2 \ Ic B 6 corre- (UNSCEAR 2008). sponds to a criterion of 1 mSv year-1. The material with

Ic [ 6 should be avoided, since these values corresponds to 3.2 Absorbed Dose Rate in Air (ADRA) dose rates higher than 1 mSv year-1 which is the highest value of dose rate recommended for population (Interna- External terrestrial gamma dose rate was calculated from tional Commission on Radiological Protection 2009). the concentrations of the radionuclides in building mate- -1 rial. ADRA in nGy h at 1 m above the ground level was 3.4 External Hazard Index (Hex) calculated using equation (UNSCEAR 2008): The external hazard index is another criterion to assess the ADRA ¼ 0:461ARa þ 0:623ATh þ 0:417AK: ð2Þ radiological suitability of a building material. Beretka and Mathew (1985) prescribed the following equation to assess 3.3 Gamma Index (Ic) the external hazard:

Hex ¼ CRa=370 þ CTh=259 þ CK=4810  1; ð4Þ Another radiation hazard index, called the gamma activity concentration index, Ic, has been defined by the European where CRa, CTh, and CK are the activity concentrations in Commission (EC 1999) and is given as below: Bq kg-1 of 226Ra, 232 Th, and 40K. For the safe use of a material in the construction of dwellings, the above crite- Ic ¼ ARa=300 þ ATh=200 þ AK=3000: ð3Þ rion was proposed (Hin B 1).

123 Radioactivity in Building Materials of Pudukkottai Geological Region, Tamil Nadu, India Page 5 of 12 4

Table 2 Activity concentrations of primordials in soils of Pudukkottai district

-1 -1 -1 Sampling station Station code Activity concentration (Bq kg )Raeq (Bq kg ) D (nGy h )Ic Hex 226Ra 232Th 40K

Viralimalai So1 14 ± 468± 10 446 ± 40 146 66 0.89 0.39 Kudumiyanmalai So2 13 ± 252± 9 430 ± 38 120 55 0.76 0.32 Rajagiri So3 5 ± 437± 9 187 ± 36 73 33 0.42 0.20 Annavasal So4 7 ± 443± 8 460 ± 32 105 48 0.66 0.28 Irumbali So5 8 ± 454± 7 480 ± 43 122 56 0.76 0.33 Nartamalai So6 8 ± 570± 11 446 ± 46 142 64 0.84 0.38 Kulathur So7 35 ± 7 177 ± 16 676 ± 46 340 151 1.98 0.92 Keeranur So8 9 ± 481± 10 652 ± 41 174 80 1.06 0.47 Parambur So9 8 ± 458± 9 372 ± 38 120 54 0.71 0.32 Melur So10 7 ± 453± 9 428 ± 38 116 53 0.71 0.31 Kunnandarkovil So11 5 ± 478± 10 552 ± 42 159 72 0.93 0.43 Moodampatti So12 8 ± 552± 8 420 ± 38 114 52 0.70 0.31 Mudukkulam So13 10 ± 448± 5 442 ± 8 109 52 0.71 0.30 Nathamadaipatti So14 9 ± 3 112 ± 10 540 ± 38 211 94 1.19 0.57 Gandarvakottai So15 5 ± 198± 1 382 ± 3 172 78 0.96 0.47 Thuvar So16 2 ± 135± 8 456 ± 36 88 41 0.56 0.24 Ambukovil So17 20 ± 552± 9 398 ± 32 126 58 0.82 0.34 Mangottai So18 24 ± 464± 8.9 447 ± 37 151 68 0.96 0.40 Karambakudi So19 9 ± 4 124 ± 10 538 ± 39 229 102 1.28 0.62 Ganapathipuram So20 14 ± 587± 11 383 ± 44 168 75 0.97 0.45 Vannarapatti So21 16 ± 557± 9 394 ± 42 128 59 0.81 0.35 Varapur So22 15 ± 368± 7 428 ± 3 145 66 0.89 0.39 Puthambur So23 MDA 45 ± 8 378 ± 33 93 44 0.57 0.26 Mullur So24 14 ± 469± 8 465 ± 37 149 68 0.91 0.40 Nathampannai So25 6 ± 5 113 ± 12 541 ± 46 209 94 1.18 0.57 Ponnamaravathy So26 24 ± 5 124 ± 10 516 ± 39 240 107 1.40 0.65 Thenur So27 18 ± 5 113 ± 13 470 ± 38 216 96 1.25 0.58 Sevalur So28 7 ± 458± 9 229 ± 35 107 48 0.60 0.29 Sundaram So29 21 ± 5 109 ± 12 550 ± 45 219 98 1.30 0.59 Sithur So30 7 ± 448± 5 270 ± 38 97 44 0.57 0.26 Peraiyur So31 7 ± 434± 9 470 ± 37 92 43 0.61 0.25 Kottaiyur So32 13 ± 458± 9 437 ± 39 129 59 0.80 0.35 Neivasal So33 8 ± 659± 8 400 ± 41 124 56 0.75 0.33 Allanvayal So34 7 ± 443± 7 420 ± 42 100 47 0.64 0.27 Valayampatti So35 7 ± 464± 9 399 ± 38 129 58 0.76 0.35 Kayampatti So36 13 ± 465± 9 454 ± 38 142 65 0.87 0.38 Thiruvarangulam So37 3 ± 24± 10 386 ± 41 95 20 0.91 0.76 Settivayal So38 12 ± 7 162 ± 9 483 ± 32 282 124 1.53 0.71 Kadalur So39 15 ± 5 144 ± 11 512 ± 35 262 116 1.46 0.35 Pachikottai So40 9 ± 463± 9 397 ± 36 131 59 0.77 0.33 Kalangudi So41 9 ± 458± 7 412 ± 32 123 56 0.75 0.29 Kurumbur So42 8 ± 552± 12 315 ± 42 107 49 0.64 0.28 Melapattu So43 8 ± 550± 11 309 ± 43 102 46 0.62 0.41 Keelavijayapuram So44 5 ± 472± 11 565 ± 47 152 69 0.91 0.36 Vengur So45 42 ± 637± 14 490 ± 46 61 62 0.99 0.31 Vellatumangalam So46 7 ± 654± 2 388 ± 33 114 52 0.69 0.33 Thanikadu So47 5 ± 462± 10 376 ± 39 123 56 0.72 0.49

123 4 Page 6 of 12 G. S. Pillai et al.

Table 2 continued

-1 -1 -1 Sampling station Station code Activity concentration (Bq kg )Raeq (Bq kg ) D (nGy h )Ic Hex 226Ra 232Th 40K

Arasur So48 20 ± 487± 9 508 ± 37 183 83 1.12 0.41 Kumulur So49 18 ± 473± 9 383 ± 33 152 69 0.93 0.41 Peranur So50 17 ± 572± 9 390 ± 42 150 68 0.91 0.43 Veelimar So51 17 ± 377± 8 413 ± 32 159 71 0.96 0.30 Pilangudi So52 MDA 56 ± 9 374 ± 39 110 51 0.65 0.44 Nemmelivayal So53 9 ± 485± 9 397 ± 36 162 72 0.93 0.24 Perumanathur So54 6 ± 439± 8 370 ± 34 89 41 0.56 0.26 Seyyamam So55 8 ± 443± 8 342 ± 28 96 44 0.60 0.56 Range B2.03–42 4–177 187–676 61–340 20–151 0.32–1.98 0.11–0.92 Mean ± SD 12 ± 870± 33 436 ± 86 145 ± 54 66 ± 24 0.87 ± 0.30 0.39 ± 0.15

Table 3 Activity concentrations of primordials in cultivated soils of Pudukkottai district

-1 -1 -1 Sampling station Station Code Activity concentration (Bq kg )Raeq (Bq kg ) D (nGy h )Ic Hex 226Ra 232Th 40K

Annavasal Cs1 7 ± 470± 9 511 ± 39 147 487.1 0.88 0.39 Kunnandarkovil Cs2 6 ± 557± 10 446 ± 43 121 256.6 0.73 0.33 Nartamalai Cs3 4 ± 368± 9 399 ± 36 132 385.4 0.76 0.36 Thuvar Cs4 18 ± 470± 9 542 ± 39 160 251. 1.01 0.43 Gandarvakottai Cs5 6 ± 469± 8 341 ± 32 130 412.3 0.74 0.35 Mangottai Cs6 MDA 153 ± 11 293 ± 37 242 252.6 1.24 0.66 Nathamppannai Cs7 8 ± 484± 9 247 ± 33 147 481.7 0.80 0.39 Sevalur Cs8 7 ± 450± 9 406 ± 88 110 232.2 0.67 0.30 Ponnamaravathy Cs9 21 ± 2 127 ± 2 531 ± 13 240 521.4 1.41 0.66 Peraiyur Cs10 6 ± 470± 10 467 ± 41 141 384.6 0.83 0.38 Kottaiyur Cs11 6 ± 442± 9 221 ± 37 83 332.3 0.49 0.22 Valayampatti Cs12 13 ± 399± 3 355 ± 8 179 352.7 1.03 0.49 Kalangudi Cs13 MDA 58 ± 10 504 ± 41 121 328.2 0.74 0.33 Thiruvarangulam Cs14 5 ± 485± 10 589 ± 11 168 259.8 1.01 0.46 Settivayal Cs15 9 ± 387± 8 202 ± 10 148 412.9 0.81 0.40 Vengur Cs16 7 ± 441± 9 256 ± 37 86 258.4 0.51 0.23 Melapattu Cs17 MDA 118 ± 10 259 ± 37 189 112.1 0.98 0.51 Kurumbur Cs18 6 ± 560± 8 299 ± 3 111 197.8 0.65 0.31 Peranur Cs19 7 ± 449± 9 304 ± 37 123 219.4 0.60 0.27 Kumulur Cs20 15 ± 199± 7 379 ± 2 183 221.6 1.06 0.50 Perumanathur Cs21 4 ± 351± 10 301 ± 48 100 310.1 0.58 0.27 Seyyamam Cs22 9 ± 598± 7 309 ± 9 172 548.7 0.95 0.47 Range B2.03–21 41–153 202–589 83–242 112.1–548.7 0.49–1.41 0.22–0.66 Mean ± SD 9 ± 477± 29 377 ± 121 145 ± 43 328.1 ± 115.2 0.84 ± 0.23 0.40 ± 0.12

4 Results and Discussion in Table 1, out of 21 stations, only 11 stations registered 226Ra activity which ranged from 6 Bq kg-1 (St19) to The activity concentrations of 226Ra, 232Th, and 40K mea- 52 Bq kg-1 (St9) with an average value of sured for 118 building materials collected from Pudukkottai 16 ± 16 Bq kg-1 and in the remaining ten stations regis- district were presented in Tables 1, 2, 3, 4, 5, and 6. As shown tered MDA (B2.03 Bq kg-1). On the other hand, the

123 Radioactivity in Building Materials of Pudukkottai Geological Region, Tamil Nadu, India Page 7 of 12 4

Table 4 Activity concentrations of primordials in sands of Pudukkottai district

-1 -1 -1 Sampling station Station code Activity concentration (Bq kg )Raeq (Bq kg ) D (nGy h )Ic Hex 226Ra 232Th 40K

Vellar River Sa1 5 ± 742± 5 342 ± 4 89 42 0.56 0.25 Agniyar River Sa2 10 ± 658± 4 297 ± 1 114 52 0.68 0.31 Koraiyar River Sa3 7 ± 238± 2 280 ± 8 82 38 0.52 0.23 Gundar River Sa4 10 ± 860± 1 398 ± 8 123 57 0.76 0.34 Pambar River Sa5 12 ± 668± 3 422 ± 9 139 64 0.86 0.38 Kuluvanar River Sa6 14 ± 176± 3 433 ± 6 153 70 0.94 0.42 Range 5–14 38–76 280–33 82–153 38–70 0.52–0.94 0.23–0.42 Mean ± SD 10 ± 357± 15 362 ± 65 117 ± 28 54 ± 12 0.72 ± 0.17 0.32 ± 0.08

Table 5 Activity concentrations of primordials in bricks of Pudukkottai district

-1 -1 -1 Sampling station Station code Activity concentration (Bq kg )Raeq (Bq kg ) D (nGy h )Ic Hex 226Ra 232Th 40K

Annavasal Br1 18 ± 565± 8 421 ± 35 143 65.13 0.89 0.39 Keeranur Br2 8 ± 452± 6 358 ± 26 110 50.03 0.67 0.30 Mudukkulam Br3 26 ± 632± 8 221 ± 25 89 40.56 0.62 0.24 Varapur Br4 18 ± 825± 9 225 ± 15 71 32.80 0.50 0.19 Peraiyur Br5 9 ± 558± 6 491 ± 32 130 59.66 0.80 0.35 Allanvayal Br6 8 ± 262± 9 402 ± 15 128 57.91 0.76 0.34 Settivayal Br7 14 ± 259± 9 356 ± 31 126 56.95 0.77 0.34 Perumanathur Br8 29 ± 628± 5 215 ± 36 86 39.28 0.62 0.23 Range 8–29 25–65 215–491 71–143 33–65 0.50–0.89 0.19–0.39 Mean ± SD 16 ± 848± 17 336 ± 105 110 ± 26 50 ± 12 0.70 ± 0.13 0.30 ± 0.07

Table 6 Activity concentrations of primordials in cements of Pudukkottai district

-1 -1 -1 Station Code Activity Concentration (Bq kg )Raeq (Bq kg ) D (nGy h )Ic Hex 226Ra 232Th 40K

Ce 1 29 ± 243± 574± 25 96 42.46 0.63 0.26 Ce 2 39 ± 357± 7 126 ± 30 130 57.7 0.85 0.35 Ce 3 24 ± 247± 494± 26 98 43.4 0.62 0.27 Ce 4 27 ± 154± 782± 27 111 48.51 0.68 0.3 Ce 5 28 ± 246± 443± 23 97 42.51 0.62 0.26 Ce 6 31 ± 287± 8 179 ± 30 169 74.33 1.01 0.46 Range 24–39 43–87 43–179 96–169 42–74 0.26–0.46 0.33–0.54 Mean ± SD 30 ± 656± 16 100 ± 52 117 ± 29 51 ± 13 0.73 ± 0.16 0.32 ± 0.08 concentration of 232Th was recorded in 20 stations, and the 226Ra in all the samples were within that of the world average concentration varied from 5 Bq kg-1 (St13) to 387 Bq kg-1 except the stations (St2, St9, St11, St12, and St17) (St17) with an average value of 163 ± 121 Bq kg-1 and the (UNSCEAR 2008). The activity concentrations of 232Th and concentration of 40K registered in all the stations which 40K in St4, St13, St14, St18, St19, and St21 were within that swung from 92 Bq kg-1 (St14) to 1119 Bq kg-1 (St1) with of the world average of 45 and 412 Bq kg-1 and that in the an average value of 299 ± 206 Bq kg -1. Of all the stone remaining stations exceeded the world average. It is evident samples measured in this study, the activity concentrations of from Table 2 that the activity concentration of 226Ra in soil

123 4 Page 8 of 12 G. S. Pillai et al. samples was varied from 2 Bq kg-1 (So16) to 42 Bq kg-1 and in the remaining 3 stations registered MDA (So45) with an average value of 12 ± 8Bqkg-1 and 232Th (B2.03 Bq kg-1). 232Th concentrations fluctuated from from 4 Bq kg-1 (So37) to 177 Bq kg-1 (So7) with an 41 Bq kg-1 (Cs16) to 153 Bq kg-1 (Cs6) with an average average value of 70 ± 33 Bq kg-1. The activity concen- value of 77 ± 29 Bq kg-1 and 40K from 202 Bq kg-1 tration of 40K fluctuated from 187 Bq kg-1 (So3) to (Cs11) to 589 Bq kg-1 (Cs14) with an average value of 676 Bq kg-1 (So7) with an average value of 377 ± 121 Bq kg-1. The activity concentrations of 238Uin 436 ± 86 Bq kg-1. Of all the samples measured in this all the samples were within the world average (UNSCEAR study, Kulathur (So7) and Vengur (So45) recorded the 2008). However, the activity concentrations of 232Th in all highest concentration of 226Ra. The activity concentration of the samples exceeded the world average except in two sta- cultivated soil samples is presented in Table 3. It was evident tions (Cs11 and Cs16). Similarly, the activity concentrations from Table 3 that out of 22 stations, 19 stations registered of 40K obtained for 15 stations within the world average. As 226Ra ranging from 4 Bq kg-1 (Cs4 and Cs21) to seen from Table 4, the activity concentration of 226Ra ranged 21 Bq kg-1 (Cs9) with an average value of 9 ± 4Bqkg-1 from 5 Bq kg-1 (Sa1) to 14 Bq kg-1 (Sa6) with an average

Fig. 2 Frequency distribution of 238U, 232Th, and 40K in building materials of Pudukkottai district 123 Radioactivity in Building Materials of Pudukkottai Geological Region, Tamil Nadu, India Page 9 of 12 4

-1 40 Ra-226 48 ± 17 Bq kg . The activity concentration of K from 1200 -1 -1 Th-232 215 Bq kg (Br8) to 491 Bq kg (Br 5) with an average K-40 value of 336 ± 105 Bq kg-1. Table 6 gives the values of the 1000 activity concentrations of primordial radionuclides in 226 800 cement samples. The activity concentration of Ra swung from 24 Bq kg-1 (Ce3) to 39 Bq kg-1 (Ce2) with an average 600 value of 30 ± 6Bqkg-1 and 232Th from 43 Bq kg-1 (Ce 1) to 87 Bq kg -1 (Ce6) with an average value of 400 -1 40 Activity (Bq/kg) Activity 56 ± 16 Bq kg . The activity concentration of K oscil- -1 -1 200 lated from 43 Bq kg (Ce5) to 179 Bq kg (Ce6) with an average value of 100 ± 52 Bq kg-1. Of all the six cement 0 samples measured in this study, the activity levels of 238U 40 0 20406080100120 and K in all the samples were within the world average, 232 Radionuclides whereas the activity concentrations of Th in all the sta- tions were higher the world average. The frequency distri- 226 232 40 Fig. 3 Natural radionuclides activity in building materials of butions of Ra, Th, and K among the building Pudukkottai district materials of Pudukkottai district are presented in Fig. 2. The values of skewness coefficient obtained for 226Ra, 232Th, and -1 232 -1 value of 10 ± 43 Bq kg and Th from 38 Bq kg 40K in the building materials for Pudukkottai district 1.32, -1 (Sa3) to 76 Bq kg (Sa3) with an average value of 2.34, and 1.11, respectively. It is evident that the distribution -1 40 57 ± 15 Bq kg . The activity concentration of K fluc- of primordial radionuclides in the building materials was -1 -1 tuated from 280 Bq kg (Sa3) to 433 Bq kg (Sa6) with asymmetric and wide range. These asymmetric primordial -1 an average value of 362 ± 65 Bq kg . Of all the six sand radionuclides in the building material are attributed to wide samples measured in this study, the activity concentrations of verities of lithological components existing in the study area. 226 Ra in all the samples were within the world average 40K concentration is relatively higher than that of both 226Ra 232 (UNSCEAR 2008). The activity concentrations of Th in and 232Th (Fig. 3). The data also indicated that 40K is uni- -1 Sa1 and Sa 3 were within the world average 45 Bq kg and formly distributed as compared to both uranium and thorium. the remaining four stations exceeded the world average. This is because of high solubility and natural abundance of 40 Similarly, K activity concentrations obtained for the sta- 40K-40 as compared to 238U and 232Th. However, 232Th tions Sa5 and Sa6 were higher than the world average value concentration is always higher than that of 226Ra. A good -1 of 412 Bq kg (UNSCEAR 2008) remaining four stations correlation existed between uranium and thorium in sand and within the world average. It is evident from Table 5, in brick stone (R2 = 0.9 and 0.6), but there is no such correlation 226 sample, the concentration of Ra oscillated from observed in soil and brick. This is may be due to sand and -1 -1 8Bqkg (Br6) to 29 Bq kg (Br3) with an average value stones are enriched with inorganic (heavy minerals), -1 232 -1 of 16 ± 8Bqkg and Th from 25 Bq kg (Br4) to whereas soil and bricks are organic species such as carbon -1 65 Bq kg (Br1) with an average value of mixed with the inorganic minerals. The natural radionuclides

Fig. 4 Mean radium equivalent activity in building materials of Pudukkottai district

123 4 Page 10 of 12 G. S. Pillai et al.

The maximum activity was found in stone (Raeq -1 -1 299 Bq kg ) and minimum in Brick (Raeq 110 Bq kg ). The variation in the concentration of primordials in building materials may be due to variation in geological formation and geochemical processes. It was observed that igneous rocks (granites) were predominant in Pudukkottai district (Geological survey of India 2006). The enrichment of monazite in igneous rock which was the source of tho- rium was responsible for the elevated radioactivity level in igneous rock as also reported by Hameed et al. 2014.Itis Fig. 5 Percentage composition of U-238, Th-232, and K-40 in building materials of Pudukkottai district noted from the literature data that minerals such as quartz, microline feldspar, and kaolinite are the major component distribution in soils and cultivated soils did not vary much responsible for the higher radioactivity content of rocks (Fig. 4). Figure 5 shows the percentage of activity concen- (Ramasamy et al. 2009). It can be concluded from the tration of primordials in the building materials of results that the radioactivity fluctuated widely even within Pudukkottai district. 226Ra represented 2–4%, 232Th: a short distance; Hameed et al. (2014) also reported that the 40 226 12–20%, and K: 78–85%. The elevated level of Ra and Raeq activity could vary greatly even if two stations were 232 Th in cement could be attributed to the mixing of fly ash separately by 5 km. The granites with high Raeq values and phosphogypsum which are enriched source of 226Ra and identified in the present study are not used as core con- 232Th (Khalifa and El-Arabi 2005). struction material. However, they were used for paving In stones, radium equivalent activity ranged from open space, closing drainage and as fencing post and hence 12 Bq kg-1 (St4) to 653 Bq kg-1 (St17) with a mean value rigorous human exposure as indoor gamma radiation was -1 naturally avoided. of 299 ± 206 Bq kg . On the other hand, Raeq of 55 soil samples fluctuated from 61 Bq kg-1 (So 45) to The mean absorbed gamma dose rate for building 340 Bq kg-1 (So7) with mean value of 145 ± 54 Bq kg-1. materials, namely, soils, cultivated soil, sand, brick, and -1 cement, was *54 nGy h-1 which is less than the per- In cultivated soils, Raeq swung from 83 Bq kg (Cs 11) to -1 242 Bq kg-1 (Cs 6) with mean value of 145 ± 43 Bq kg-1 missible limit of 55 nGy h . However, the mean absor- -1 -1 , while in sand, Raeq varied from 82 Bq kg (Sa3) to bed gamma dose rate calculated for stones (132 nGy h ) 153 Bq kg-1 (Sa6) with mean value of 117 ± 28 Bq kg-1 was higher than the world average indicating an elevated -1 and Raeq value of bricks fluctuated from 71 Bq kg (Br4) level of gamma radiation in the stones of Pudukkottai -1 to 143 Bq kg (Br1) with mean value of 110 ± district. The analysis revealed that Hex and Ic calculated -1 for the building materials were well within the safety limit 26 Bq kg . The Raeq activity of the building materials of from Pudukkottai district maintained the following (B1). descending order: Stone [ Cultivated soil & Soil [ Sand Principal component analysis (PCA) is a powerful sta- and Cement [ Brick. tistical tool, which is used widely in environmental

Fig. 6 Screen plot

123 Radioactivity in Building Materials of Pudukkottai Geological Region, Tamil Nadu, India Page 11 of 12 4

Table 7 Extraction method: principal component analysis References Component Ademola JA, Oguneletu PO (2005) Radionuclide content of concrete Variables Factor 1 building blocks and radiation dose rates in some dwellings in Ibadan, Nigiria. J Environ Radioact 81:107–113 Radium 0.557 Amrani D, Tahtat M (2001) Natural radioactivity in Algerian building Thorium 0.977 materials. Appl Radiat Isot 54:687–689 Potassium 0.785 Anjos RM, veiga R, Soares T, Santos AMA, Aguiar JG, Frasca Ra 0.992 MHBO, Brage JAP, Uzeda D, Mangia L, Facure A, Mosquera B, eq Carvalho C, Gomes PRS (2005) Natural radionuclide distribu- ADRA 0.995 tion in Brazilian commercial granites. J Radia Meas 39:245–253 Ic 0.999 Beretka J, Mathew PJ (1985) Natural radioactivity of Australian building materials, industrial wastes and by product. Health Phys Hex 0.950 48:87–95 % of variance explained 83.03 Bou-Rabee F, Bem H (1996) Natural radioactivity in building One component extracted materials utilized in the state of Kuwait. J Radioanal Nucl Chem 213(2):143–149 Chang TY, Cheng WL, Weng PS (1974) Potassium, uranium and applications. PCA is simplifying the complex and diverse thorium content of building materials of Taiwan. Health Phys relationships that exist among a set of observed variables 27:385–387 by revealing common and unobservable factors. This El-Shershaby A (2002) Study of radioactivity levels in granite of Gable Gattar II in the north eastern desert of Egypt. Appl Radiat method is applied to the data matrix for reducing the data Isot 57:131–135 to an easily interpretable form. The significance of prin- European Commission (EC) (1999) Report on radiological protection cipal components of primordial radionuclides were indi- principle concerning the natural radioactivity of building mate- cated by screen plot of eigen values (Fig. 6). The sharp rials, Directorate-general environment, nuclear safety civil protection and radiation protection, pp 1–16 decline in values from the first to second components Faanu A, Darko EO, Ephraim JH (2011) Determination of natural indicates that most of the variability of the data can be radioactivity and hazard in soil and rock samples in a mining accounted for the first component (232Th) which represents area in Ghana. J Appl Ecol 19:77–92 83.03% of the total variation of the data (Table 7). Faheem M, Mujahid SA (2008) Assessment of radiological hazards due to the natural radioactivity in soil and building material samples collected from six districts of the Punjab province- Pakistan. Radiat Meas 43:1443–1447 5 Conclusions Geological survey of India (2006) Geology and mineral resources of the states of India. Government of India. Part VI—Tamil Nadu and Pondicherry A total of 118 building materials sampled from Hameed P, Pillai GS, Satheeshkumar G, Mathiyarasu R (2014) Pudukkottai district for the analysis of natural radioactivity Measurement of gamma radiation from rocks used as building employing gamma ray spectrometry. There is a wide materials in Tiruchirappalli district, Tamil Nadu, India. J Ra- 226 232 40 dioanal Nucl Chem 300(3):1081–1088 variation in Ra, Th, and K activities. The Raeq Hewamanna R, Sumithrachchi CS, Mahawatte P, Nanayakkara HLC, activity in the building materials formed the following Ratnayake HC (2001) Natural activity and gamma dose from Sri sequence: Stone [ Cultivated soil and Soil [ Sand and Lankan clay bricks used in building construction. Appl Radiat Cement [ Brick. The present study identified seven stone Isot 54:365–369 quarries of granite rocks, namely, Annavasal, Rajagiri, International Atomic Energy Agency (IAEA) (2004) Soil sampling for environmental contaminants, IAEA-TECDOC-1415 Viralimalai, Narthamppannai, Ganapathipuram, Muduku- International Commission on Radiological Protection (2009) (ICRP). lam, and Ponnamaravathy which registered Raeq value The recommendations of the International Commission on (Range 397–762 Bq kg-1) higher than the permissible Radiological Protection. ICRP Publication 103. Ann. ICRP limit. Although these granites were not used in core con- 37:2–4 Khalifa NA, El-Arabi AM (2005) Natural radioactivity in farm soil struction, the radiological risk to human population living and phosphate fertilizer and its environmental implications in closer to these granite rocks needed to be further investi- Qena governorate, Upper Egypt. J Environ Radioact 84(1):51–64 gated by cytogenetic studies among the quarry miners. Khan K, Khan HM (2001) Natural gamma-emitting radionuclides in Pakistani Portland cement. Appl Radiat Isot 54:861–865 Overall, the mean Raeq activity of samples collected in Kolb W, Schmier H (1978) Building materials induced radiation Pudukkottai is well below the recommended value and exposure of the population. In: Radioactivity in consumer does not pose any radiological risk to the general public. Products U.S. Nuclear Regulatory Commission Washington, DC, Report NUREG/CP-0001, pp 344–349 Acknowledgements The authors would like to acknowledge Atomic Kolo MT, Baba-Kutigi AN, Olarinoye IO, Sharifat I (2012) Assess- Energy Regulatory Board, Govt. India for funding (Project No: ment of natural radioactivity levels and radiation hazards in the AERB/CSRP/45/05/2010) and Shri. R. Mathiyarasu, HSEG, IGCAR tertiary institutions in Minna, Niger State, Nigeria Continental. for his technical support. J Environ Sci 6(3):25–31

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Kovler K, Haquin G, Knmanasherov V, Neeman E, Lavi N (2002) UNSCEAR (2008) United Nations Scientific Committee on the effect Natural radionuclides in building materials available in Israel’. of atomic radiation report to the general assembly. Annex B Build Environ 37:531–537 Exposures of the public and workers from various sources of Krstic D, Nikezic D, Stevanovic N, Vucic D (2007) Radioactivity of radiation some domestic and imported building materials from South Xinwei L (2005) Natural radioactivity in some building materials of Eastern Europe. Radiat Meas 42:1731–1736 Xian, China. J Radiat Meas 40:94–97 Kumar V, Ramachandran TV, Prasad R (1999) Natural radioactivity of Indian building materials and by-products. Appl Radiat Isot 51:93–96 Dr. G. Sankaran Pillai is a Kumar A, Kumar M, Singh B, Singh S (2003) Natural activities of Research Associate at Radio- 238U. 232Th and 40K in some Indian building materials’. Radiat logical Safety Division (RSD), Meas 32:465–469 Health Safety and Environment Mishra UC, Sadasivan S (1971) Natural radioactivity levels in Indian Group (HSEG), Indira Gandhi soil. J Sci Ind Res 30:59–62 Centre for Atomic Research, Papaefthymiou H, Gouseti O (2008) Natural radioactivity and Kalpakkam. He received his associated radiation hazards in building materials used in both Post Graduate (M.Sc.,) and Peloponnese, Greece. Radiat Meas 43:1453–1457 Under Graduate (B.Sc.,) degree Pereira CE, Vaidyan VK, Sunil A, Byju SB, Jose RM, Jojo PJ (2011) in Chemistry from Bharathi- Radiological assessment of cement and clay based building dasan University, Tiruchirap- materials from southern coastal region of Kerala. Indian J Pure palli. He obtained his Ph.D., Appl Phys 49:372–376 degree from Bharathidasan Pillai GS, Hameed PS, Khan SMMN (2015) Natural radioactivity University. He published more levels in the soils and human risk assessment in Tiruchirappalli than 15 research papers in district (Tamil Nadu, India). J Radioanal Nucl Chem. doi:10. international journals. His research interests are Radiation Chemistry, 10007/s10967-015-4367-z Radiation Ecology, Environmental Radioactivity and Radiation Pillai GS, Hameed PS, Khan SMMN (2016) Radioactivity in building Measurements. materials and assessment of risk of human exposure in Tiruchirappalli District (Tamil Nadu, India). J Hazard Tox Dr. K. Jeevarenuka is a Pro- Radioact Waste 20(3):04016004. doi:10.1061/(ASCE)HZ.2153- fessor and head, Department of 5515.0000320 Civil Engineering, Shivani Ramasamy V, Senthil S, Meenakshisundaram V (2009) Distribution Engineering College, Tiruchi- of natural radionuclides and minerals in beach sediments from rappalli. She obtained her north east coast of Tamilnadu, India. Afr J Basic Appl Sci M.Tech., degree from Kerala 1(1–2):15–20 University and B.E., degree Ravisankar R, Vanasundari K, Chandrasekaran A, Rajalakshmi A, from Madurai Kamarajar Suganya M, Vijayagopal P, Meenakshisundaram V (2012) University. Her areas of Measurement of natural radioactivity in building materials of research are Structural Engi- Namakkal, Tamil Nadu, India using gamma-ray spectrometry. neering, Waste Water Treat- Appl Radiat Isot 70:699–704 ment and Radiation Samet JM, Tang EA, Boffetta P, Hannan LM, Marston SO, Thun MJ, Measurements. Rudin CM (2009) Lung cancer in never smokers: clinical epidemiology and environmental risk factors. Clin Cancer Res 15(18):5626–5645 Stoulos S, Manolopoulou M, Papastefanou C (2003) Assessment of natural radiation exposure and radon exhalation from building Dr. P. Shahul Hameed Gradu- materials in Greece. J Environ Radioact 69:225–240 ated at St. Xavier’s College, Taskin H, Karavus M, Topozoglu A, Hidiroglu S, Karahan G (2009) Palayamkottai and Post gradu- Radionuclide concentrations in soil and lifetime cancer risk due ated at Presidency College, to gamma radioactivity in Kirklareli Turkey. J Environ Radioact Chennai. He obtained his Ph.D., 100(1):49–53 from C.A.S in marine Biology, Tsabaris C, Elefherriou G, Kapsimalis V, Anagnostou C, Vlastou R, Annamalai University, Chi- Durmishi C, Kedhi M, Kalfas CA (2007) Radioactivity levels of dambaram. His areas of research recent sediment in the Butrint Lagoon and the adjacent coast of include Radiation Ecology, Albania. Appl Radiat Isot 65(445–453):2007 Water pollution, Bio-monitor- Turhan S (2008) Assessment of the natural radioactivity and ing, Bioremediations and Ther- radiological hazards in Turkish cement and its raw materials. mal Ecology. He has operated J Environ Radioact 99(404–414):2009 eight major research projects UNSCEAR (1993) United Nations Scientific Committee on the Effect and Guided 13 Ph.Ds under of Atomic Radiation, Report to the general assembly. New York, Bharathidasan University and USA published about 80 research papers. Presently, he is working as UNSCEAR (2000) United Nations Scientific Committee on the Effect Director, Environmental Research Centre, J.J. College of Engineering of Atomic Radiation Report to the general assembly, Sources & Technology, Tiruchirappalli. and effects of ionizing radiation. United Nations, New York, vol I

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