Investigation of ionizing radiation shielding effectiveness of decorative building materials used in Bangladeshi dwellings

Author’s Accepted Manuscript Investigation of ionizing radiation shielding effectiveness of decorative building materials used in Bangladeshi dwellings Sabina Yesmin, Bijoy Sonker Barua, Mayeen Uddin Khandaker, Mohammed Tareque Chowdhury, Masud Kamal, M.A. Rashid, M.M.H. Miah, D.A. Bradley

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To appear in: Radiation Physics and Chemistry Received date: 29 September 2016 Revised date: 27 November 2016 Accepted date: 29 November 2016 Cite this article as: Sabina Yesmin, Bijoy Sonker Barua, Mayeen Uddin Khandaker, Mohammed Tareque Chowdhury, Masud Kamal, M.A. Rashid, M.M.H. Miah and D.A. Bradley, Investigation of ionizing radiation shielding effectiveness of decorative building materials used in Bangladeshi dwellings, Radiation Physics and Chemistry, http://dx.doi.org/10.1016/j.radphyschem.2016.11.017 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.

Investigation of ionizing radiation shielding effectiveness of decorative building materials used in Bangladeshi dwellings Sabina Yesmina, Bijoy Sonker Baruab, Mayeen Uddin Khandakerc,, Mohammed Tareque Chowdhuryd, Masud Kamald, M. A. Rashida, M. M. H. Miahe, D. A. Bradleyf,g a

Department of Physics, Chittagong University of Engineering and Technology, Chittagong, Bangladesh Department of Civil Engineering, Southern University Bangladesh, Chittagong, Bangladesh c Department of Physics, University of Malaya, 50603 Kuala Lumpur, Malaysia d Atomic Energy Center, Bangladesh Atomic Energy Commission, Chittagong, Bangladesh e Department of Physics, University of Chittagong, chittagong 4331, Bangladesh f Department of Physics, University of Surrey, Guildford, Surrey, UK g Sunway University, Institute for Health Care Development, Jalan Universiti, 46150 PJ, Malaysia b

Highlights Studies of decorative building materials for shielding of ionizing radiation High energy photon beam were used to obtain various interaction properties Marble stone ‘Carrara’ from Italy shows suitability to be used as shielding material Abstract Following the rapid growing per capita income, a major portion of Bangladeshi dwellers is upgrading their non-brick houses by rod-cement-concrete materials and simultaneously curious to decorate the houses using luxurious marble stones. Present study was undertaken to investigate the gamma-ray attenuation co-efficient of decorative marble materials leading to their suitability as shielding of ionizing radiation. A number of commercial grades decorative marble stones were collected from home and abroad following their large-scale uses. A well-shielded HPGe γ-ray spectrometer combined with associated electronics was used to evaluate the mass attenuation coefficients of the studied materials for high energy photons. Some allied parameters such as half-value layer and radiation protection efficacy of the investigated marbles were calculated. The results showed that among the studied samples, the marble ‘Carrara’ imported from Italy is suitable to be used as radiation shielding material. Keywords: Marble stones, HPGe -ray spectrometer, Mass attenuation coefficient, Shielding materials. Introduction



E-mail: [email protected]; Tel.: +601115402880; Fax: +60379674146,

Background radiation is the ubiquitous ionizing radiation present in our environment. It originates from a variety of sources, both natural and artificial. Nowadays, the use of artificial radiation/radioactive isotopes has been increasing in nuclear research, nuclear power, space research, medicine, agriculture etc., and consequently contributing in an enhancement and/or redistribution of background radiation in our environment. According to the international atomic energy agency (IAEA), "Exposure to radiation from natural sources is an inescapable feature of everyday life in both working and public environments. This exposure is in most cases of little or no concern to society, but in certain situations the introduction of health protection measures needs to be considered”. Among the various types of radiation, gamma radiation has the most penetration capability and can travel a long distance, and thus forms the major sources of external radiation exposures to human beings. Since human beings spent around 80% of their time with in-house activity, the radiation protection inside houses should be given most priority. One of the basic criteria of radiation protection is to arrange a shielding material in between the radiation source and human population. Many materials such as Lead, Concrete etc are typically used to protect and/or separate the living environment from the radiation sources. To obtain the radiation protection capability of any material, it is necessary to conduct the study of photon interactions with the materials of interest. Bangladesh, a South Asian country marked with a population of 170 million, is the world's eighth-most populous country. It has the third-largest economy and military in South Asia after India and Pakistan. According to the International Monetary Fund (IMF), Bangladesh's economy is the second fastest growing major economy in 2016, with a rate of 7.1% [1,2]. The per-capita income estimated by the IMF for the year 2016 is US$3,840 (PPP) and US$1,386 (Nominal) [3], which indicates to becoming a mid-income nation. Along with this growing economy and increasing economic solvency of the population of Bangladesh, the existing houses made by brick/non-brick walls with tin shade are being replaced by modern building materials. The building materials must provide adequate protection to keep acceptable probability of harmful effects on personnel at a reasonable cost. Due to the huge population density, the real estate and construction industry are playing an important role for human settlements in a sustainable manner, and developing fashionable structures using rod-cement-concrete materials throughout the country. Marble is widely used as a furnishing material in modern building construction worldwide as well as in Bangladesh due to its polished surface and availability in a variety of

attractive colors. This metamorphic rock is in fact prized for the beauty and richness of its finished surface. Recognizing the increasing uses of stones as decorative agents in construction industry, it is imperative to assess the suitability of various kinds of marbles for shielding of ionizing radiation. Assessment of mass attenuation coefficient is a basic property that indicates the radiation shielding capability of any particular material. In connection to this, a number of works dealing with the mass attenuation coefficient of building materials have been found in the literature [410]. However, in Bangladesh, these types of metamorphic rocks have not been analyzed for the purpose of radiation shielding. In this study, an attempt was made to measure the gamma-ray interaction parameters such as linear attenuation coefficient, mass attenuation coefficient, halfvalue layer and radiation protection efficiency of marble stones to assess residential safety. Materials and methods A total of 6 marble samples of six varieties (depending on type and origin) used as decorative assembly in building constructions in Bangladesh were collected from marble dealers in and around Chittagong city for the measurement of properties relevant to radiation shielding. Detailed information about the samples tested is summarized in Table 1. All the samples were brought to the laboratory, they were properly cataloged, washed, and dried for complete removal of moisture. The geometry of all the marble samples were arranged/prepared following the same diameter (7.5 cm) of the envelops of the gamma-ray detector located at the Chittagong atomic energy center, Bangladesh. To understand the gamma-ray shielding effectiveness of these samples, the mass attenuation coefficients of marbles were measured using the HPGe gamma-ray spectrometer with a relative efficiency of 20%, resolution 1.8 keV (FWHM) at 1332 keV of 60

Co. The detector (GC2018, CANBERRA, USA) was coupled with digital spectrum analyzer

(DSA-1000) and the gamma-ray spectra were analyzed by using the program GENIE 2000. The detector is shielded by a lead cylindrical shield of 9 cm thickness and 40 cm height with an inner lining of 1.6 cm-thick steel plate, which provides an efficient suppression of the background radiation present at the laboratory environment. The diagram of the narrow beam γ-ray transmission geometry is shown in Fig. 1. The standard gamma-ray point source

60

Co provided

by the IAEA was used herein. The distance between source and detector was 22 cm. Samples were positioned on a specimen holder at 1.5 cm from the detector. The intensities of photon energy were measured without and with placing the investigated samples between source and the detector. The intensities of incident (I0) and transmitted (I) photon were measured for a time duration of 80,000 seconds by selecting a narrow symmetrical region with respect to the centroid of the photo peak. The net peak area presents the intensity of gamma-rays with statistical accuracy better than 0.3 %. Studied interaction parameters The mass attenuation coefficient is a measure of the average number of interactions between incident photons and matter that occur in a given mass per unit area thickness of the substance under investigation. When a narrow beam of mono-energetic photons penetrates a layer of material with mass thickness t (the mass per unit area) it follows the attenuation law given by Lambert-Beer ⁄

Where, I0 and I are the incident and transmitted intensity of photons, respectively, ρ is the mass density, µ is the attenuation coefficient which varies with the density of the absorber. The mass attenuation coefficient, μ/ρ for a compound is given by ⁄

∑

⁄

Where, wi and (μ/ρ)i are the weight fraction and mass attenuation coefficient of the i-th constituent element, respectively. The half value layer (HVL) of the sample material was calculated by using the following Eq. (3): ⁄

Where, x1/2 and μ are the HVL and linear attenuation coefficient, respectively. The radiation protection efficiency of a building material (in this case marble) is calculated by using the following equation:

(

)

Results and discussion The two photon energies 1173.4 and 1332.7 keV emanated from the

60

Co point source, were

applied to the investigated marble stones to determine their shielding capability. The measured shielding parameters are given in Table 2. The mass attenuation coefficients of these materials measured at the two mentioned energies are shown in Fig. 2 together with their uncertainties. At the elevated energy 1332.7 keV, the mass attenuation coefficients of the studied marble samples increased except the two samples Marmara Zebra and Perlato Bianco, where it happens to down. Out of these six marbles, the Carrara sample has unparalleled value about 2.2 times higher than the others do. The variations of the mass attenuation coefficients with the 1173.4 and 1332.7 keV photon energies for all investigated marble samples have been presented in Fig. 3. In these correlations, R2 was found over 1. Table 3. shows the shielding quality of studied marble stones with the literature data for concrete, soil, brick, and cement. The half value layer (HVL) of any materials is the term to depict the effectiveness of gamma-ray shielding. HVL is the thickness of an absorber that will reduce the radiation to half [4,5,15] of its initial amount. Like the attenuation coefficient, it is a photon energy dependant parameter. Increasing the penetrating energy of a stream of photons results to an increase of a material's HVL. Figure 4 of HVL and Fig. 2 of mass attenuation coefficients illustrate that the HVL is inversely proportional to the attenuation coefficient. The range of half value layer (in cm) of these investegated marble samples is found as 1.7-4.6, whereas the Concrete, Steel, Lead and Tungsten due to

60

Co have been found as 6.05, 2.16, 1.25 and 0.79, respectively [16]. On the

other hand, the estimated radiation protection efficiency (RPE) of our investigated marbles stones are presented in Fig. 5, which shows that the marble stone Carrara has higher value (almost double) of radiation protection efficiency than the other studied stones herein. Conclusions

We measured mass attenuation coefficients and other parameters for some marble stones, which are commonly used as decorative building materials in Bangladeshi dwellings. The results give an idea about a comparison of the investigated marble stones in terms of radiation shielding. The marble sample ‘Carrara’ imported from Italy found more suitable as a radiation shielding materials than the other samples studied herein. In fact, uses of Carrara can beneficially address the issues of radiation shielding, and adopting of safety measures with radiation emergencies in civil engineering constructions etc. Acknowledgements The author (S. Yesmin) thanks to the staffs of the HPGe gamma-ray spectrometry facility of Atomic Energy Center, Chittagong for their kind cooperation during sample measurements.

References [1] "Bangladesh world's 2nd most pro-free market country". Dhaka Tribune. November 1, (2014). [2] Devnath, A. "Record Exports Seen Rising as Bangladesh Woos U.S. Consumers". Bloomberg.com, Published on January 25, (2016). [3] "Bangladesh's per capita income $1,314". The Daily Star. May 15, 2015. Retrieved on March 3, (2015). [4] Akkurt, I., Kilincarslan, S., Basyigit, C., Mavi, B., Akyildirim, H. 2009. Investigation of photon attenuation coefficient for pumice. Int. J. Phys. Sci. 4(10), 588-591. [5] Mavi, B. 2012. Experimental investigation of γ-ray attenuation coefficients for granites. Ann. Nucl. En. 44, 22-25. [6] Awadallah, M.I., Imran, M.M.A. 2007. Experimental investigation of γ-ray attenuation in Jordanian building materials using HPGe-spectrometer. J. Environ. Rad. 94(3), 129-136. [7] Alam, M.N., Miah, M.M., Chowdhury, M.I., Kamal, M., Ghose, S., Rahman, R. 2001. Attenuation coefficients of soils and some building materials of Bangladesh in the energy range 276-1332 keV. Appl. Radiat. Isot. 54(6), 973-976. [8] Mann, H.S., Brar, G.S., Mudahar, G.S. 2016. Gamma-ray shielding effectiveness of novel light-weight clay-flyash bricks. Radiat. Phys. Chem. 127, 97-101. [9] Singh, C., Singh, T., Kumar, A., Mudahar, G.S. 2004. Energy and chemical composition dependence of mass attenuation coefficients of building materials. Ann. Nucl. En. 31(10), 1199-1205. [10] Medhat, M.E. 2009. Gamma-ray attenuation coefficients of some building materials available in Egypt. Ann. Nucl. En. 36(6), 849-852.

[11] Rosa Pink Marble Price - Alibaba. www.alibaba.com › Construction & Real Estate › marble › marble price. Available at [12] Sahadath, M.H., Biswas, R., Huq, M.F., Mollah. A.S. 2016. Calculation of gamma-ray attenuation parameters for locally developed ilmenite-magnetite concrete. J. Bangladesh Acad. Sci. 40(1), 11-21. [13] Mann, K.S., Kaur, B., Sidhu, G.S., Kumar, A. 2013. Investigations of some building materials for γ-rays shielding effectiveness. Radiat. Phys. Chem. 87, 16–25. [14] Damla, N., Cevikb, U., Kobyab, A.I., Celikc, A., Celikb, N., Van. Griekend, R. 2010. Radiation dose estimation and mass attenuation coefficients of Cement samples used in turkey. J. of Hazard. Mat. 176, 644–649. [15] Akkurt, I., Akyıldırım, H., Mavi, B., Kilincarslan, S., Basyigit, C. 2010. Radiation shielding of concrete containing zeolite. Rad. Meas. 45(7), 827-830. [16] Half-Value Layer - NDE/NDT Resource Center. Available at List of Tables Table 1. Investigated samples and their related infromations [11] Sl. No.

Name of the marble stone

01

Color

Marble type

Prize/m2

Place of origin

Thickness

Rose Pink

India

1.58 cm

Pink

Calcite

20-40

02

Crema Nova

Turkey

1.74 cm

Cream

Calcite

10-50

03

Carrara

Itali

1.77 cm

White

Dolomite

20-50

04

Marmara Zebra

Turkey

1.75 cm

Grey

Dolomite

15-25

05

Perlato Bianco

Albania

1.89 cm

White

Calcite

10-35

06

Rosalia

Turkey

1.48 cm

Pink

Calcite

54-55

(US $)

Table 2. Results of the studied shielding properties with the uncertainties (± 1σ), in various marble samples used in Bangladeshi dwellings. Marble stone name Rose Pink

Energy (keV) ρ (g/cm3) 1173.4 1332.7

2.7 2.7

μ

± 1σ

μ/ρ

± 1σ

HVL

± 1σ

RP

± 1σ

0.151 0.080 0.056 0.030 4.589 1.147 21.225 5.938 0.194 0.021 0.072 0.008 3.573 0.893 26.392 1.623

1173.4 1332.7 1173.4 1332.7 1173.4 1332.7 1173.4 1332.7 1173.4 1332.7

Crema Nova Carrara Marmara Zebra Perlato Bianco Rosalia

2.68 2.68 2.691 2.691 2.73 2.73 2.661 2.661 2.72 2.72

0.159 0.170 0.399 0.413 0.190 0.184 0.175 0.157 0.181 0.189

0.061 0.035 0.036 0.054 0.033 0.030 0.038 0.032 0.053 0.050

0.059 0.063 0.148 0.154 0.070 0.067 0.066 0.059 0.067 0.070

0.023 0.013 0.014 0.020 0.012 0.011 0.014 0.012 0.019 0.018

4.369 4.080 1.735 1.678 3.644 3.761 3.955 4.413 3.826 3.657

1.092 1.020 0.434 0.419 0.911 0.940 0.989 1.103 0.956 0.914

24.118 25.589 50.691 51.866 28.308 27.563 28.190 25.678 23.516 24.455

Table 3. A comparison of the obtained mean mass attenuation coefficient with the literature. Studied sample Brick Soil Cement Concrete Marble

Average mass attenuation coefficients (μ/ρ) at photon energy of 1173.4 keV 1332.7 keV 0.055 0.051 0.057 0.054 0.057 0.052 0.060 0.055 0.078 0.081

List of Figures

References

Alam et al [7] Mann et al. [13] Damlaa et al. [14] Sahadath et al. [12] This work

5.000 2.922 3.125 4.545 2.813 2.597 3.438 2.922 3.750 3.571

Fig. 1 Schematic representation of the experimental setup of narrow beam transmission method

Mass attenuation coefficient (cm2/g)

0.18 0.16

1173.4 KeV

0.14

1332.7 KeV

0.12 0.1 0.08 0.06 0.04 0.02 0 Rose Pink Crema Nova

Carrara

Marmara Zebra

Perlato Bianco

Rosalia

Fig. 2 Experimental results of mass attenuation coefficient (μ/ρ) with uncertainties for marble samples at 1173.4 and 1332.7 keV

Rose Pink

Crema Nova 0.064

0.06 0.04

y = 0.0159x + 0.04 R² = 1

0.02 0

μ/ρ (cm2/g)

μ/ρ (cm2/g)

0.08

0.062 0.06

y = 0.0042x + 0.055 R² = 1

0.058 0.056

1173.4

1332.7

Photon Energy (keV)

1173.4

1332.7

Photon Energy (keV)

Marmara Zebra

0.154

0.07

0.152

0.069

0.15 0.148

y = 0.0051x + 0.1434 R² = 1

0.146

μ/ρ (cm2/g)

μ/ρ (cm2/g)

Carrara

0.144 1173.4

1332.7

0.068 0.067 y = -0.0022x + 0.0718 R² = 1 0.066 1173.4

Photon Energy (keV)

Photon Energy (keV)

Rosalia 0.07 μ/ρ (cm2/g)

μ/ρ (cm2/g)

Perlato Bianco 0.068 0.066 0.064 0.062 0.06 0.058 y = -0.0068x + 0.0727 R² = 1 0.056 0.054 1173.4

1332.7

0.069 0.068 0.067

y = 0.0031x + 0.0635 R² = 1

0.066 0.065

1332.7

1173.4

Photon Energy (keV)

1332.7

Photon Energy (keV)

Fig. 3. Linear correlations between photon energy and mass attenuation coefficients at 1173.4 and 1332.7 keV photon energies 1173.4 KeV

Half- value layer (cm)

6

1332.7 KeV

5 4 3 2 1 0 Rose Pink Crema Nova Carrara

Marmara Zebra

Perlato Bianco

Rosalia

Fig. 4. Half value layer of the investigated samples at 1173.4 and 1332.7 keV photon energies

Radiation Protection Efficiency of Building Materials

60

1173.4 KeV 1332.7 KeV

50 40 30 20 10 0 Rose Pink

Crema Nova

Carrara

Marmara Zebra

Perlato Bianco

Rosalia

Fig. 5. Radiation Protection Efficiency of investigated marble stones