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