International Journal of Scientific & Engineering Research, Volume 5, Issue 1, January-2014 2162

ISSN 2229-5518

Ceramic Rn222 exhalation rates from different countries

B.A. Almayahi1, *, Asaad K. Alsaedi2, Ali K. Alsaedi3, A.H. Alasadi4, Azhar S. Ali5, Raad. O. Hussein6, Hayder. H. Hussain7

Abstract—In the present study, the alpha radioactivity from radon emanated from some ceramic samples collected from different countries was measured using the can technique, containing CR-39. The average 222Rn and 226Ra concentrations are found to be 371.79 Bq m-3 and

1.68 Bq kg-1, respectively. The highest radon exhalation rate was found in Chinese ceramic. The values of effective radium content are less than the permissible value of 370 Bq kg-1.

Index Terms— ceramic, radon, CR-39, exhalation rate

—————————— ——————————


he CR-39 detectors are used for long-term measurements of radon exhalation rate. The majority of exposure to radi- ation comes from natural sources, which may be terrestri-
al (soils and rocks) or extra terrestrial (cosmic rays). 222Rn and their short-lived decay products are primary contributors to the effective dose received by the population due to natural
end of a plastic cup (6 cm X 7.5 cm). The radon level was measured using TASTRAKTM track_etch detectors with chemical composition of C12H18O7, a density of 1.32 g cm-3, and size 1 cm2 purchased from Track Analysis Systems Ltd., Bristol, UK. The radon level was measured in ceramic samples from different countries. Ceramic samples were dried at


radiation [1]. Radon levels show important variations on a
regional or local scale. The present work deals with radon ex-
halation rate in ceramic in which radon gas is emanated in the
air as a product of 238U that occur as a trace element in the nat- urally occurring materials. The most sources of indoor radon are the soil and geology under the building. Radon sources may include domestic, drinking water from drilled wells
(ground water supplies), and emanation of radon from build- ing materials, including concrete, bricks, ceramic, natural building stones, natural gypsum, and materials using indus- trial by products such as phosphor gypsum, blast furnace slag, and coal fly ash [2, 3]. The exposure of population to high con- centrations of alpha radioactivity from radon for a long period
100 °C for 3 h in an oven to ensure complete moisture
removal. The ceramic was stored at room temperature for
about 90 d before counting to achieve equilibrium for 238U and

232Th with their respective progeny [11]. In the present

calibration experiment was used to determine 222Rn gas concentration emanating from a 226Ra source with 3.3 kBq
from the International Atomic Energy Agency in a close system. After exposure, the CR-39 detectors are removed and chemically etched in a 6.25 N aqueous NaOH solution using a water bath at 70 °C for 7 h. Alpha-particle track measurement per cm2 produced by the decay of 222Rn and its daughters was conducted using an optical microscope (NOVEL, China) of 40x magnification power with USB 2.0 Camera Application V 2.3 software.
leads to pathological effects like the respiratory functional
changes and the occurrence of lung cancer [4]. CR-39 detectors
are used in radon detection and alpha-particle spectroscopy to
Radon concentration (C

RRnR) was calculated [12]

measure the natural alpha radioactivity in human and animal tissues [5-10]. The aims of this study are to ascertain the radon exhalation rate in ceramic samples.

C (Bq m−3 ) = Noto ρ

Rn ρ t

, (1)



B.A. Almayahi, Department of Environment, College of Science, Universi- ty of Kufa, Iraq.

where NRoR = activity concentration for a standard source (radium), tRoR = exposure time for standard source, ρRo R= track density for a standard source (track cm-2), ρ = track density for sample (track cm-2), and t = exposure time of the sample.
The effective radium content can be calculated [13, 14]:

Asaad K. Alsaedi, Maysan Technical Institute, Foundation of Technical

Education, Iraq.

Ali K. Alsaedi, A.H. Alasadi, Azhar S. Ali, Raad. O. Hussein, Hayder. H.

Hussain. Department of Physics, College of Science, University of Kufa, Iraq.


(Bq kg −1 ) = (



)( hA )


In this study, CR-39 detectors were placed at the closed top

IJSER © 2014

International Journal of Scientific & Engineering Research, Volume 5, Issue 1, January-2014 2163

ISSN 2229-5518

where M is the mass of the sample in kg, A is the area of a cross section of the cylindrical (m2) and h is the distance be- tween the detector and the top of the sample in m. ρ is the counted track density, k is the calibration factor of the CR-39 track detector, and T e denotes the effective exposure time.
The exhalation rate was calculated [15]:




Ex = (eλT

A(T +


−1) )

, (3)



where Ex is the radon exhalation rate (Bq kg-1 d-1), C is the measured radon concentration by the CR-39 detector (Bq m-3 d-1), λ is the decay constant of radon (d-1), T is the exposure time (d), V is the volume of the radon chamber (m3), and A is the mass of the sample.

H E = C × F × T × D (4)

where C is the radon concentration in Bq m-3, F is the 222Rn in-

door equilibrium factor (0.4), T is time (8760 h y-1), and D for dose

conversion factor (9 x 10-6 mSv y-1 (Bq m-3)-1 ).


The calibration factor obtained from the experiments is
0.0107 track cm-2 d-1 per (Bq m-3). The 222Rn and 226Ra concen-



Fig. 1. Average 222Rn concentration. The green bar represents low concentration, and the red bar represents high concentration.

trations in ceramic samples are presented in Table 1. The min- imum and maximum radon concentrations were found to be
289.47±17.34 and 443.22±21.45 Bq m-3 in C9 and C5 (ceramic, china) as shown in Fig. 1. The present results show that the
radon concentration in ceramic samples is below the limit rec- ommended (International Commission of Radiation Protec- tion) (ICRP). The mass exhalation rates in the collected ceram- ic samples are given in Table 1. The radon exhalation rate var- ied from 0.0005074 Bq kg-1 d-1 to 0.0007769 Bq kg-1 d-1.

Table 1: 222Rn and 226Ra concentrations in ceramic samples

SC= Sample Code


The 222Rn concentration in the ceramic samples varies from
289.47 to 443.22 Bq m-3 with mean 371.79 Bq m-3. The highest
radon exhalation rates are found in Chinese ceramic. Accord-
ing to EPA and ICRP, the average indoor radon level should
be 148 Bq m−3 and 300 Bq m−3, respectively, whereas 15 Bqm−3
(ranging from 1 Bq m−3 to 100 Bq m−3) of radon concentration
is found in outside air [16-18]. The annual effective dose
equivalent ranges from 2.08 mSv y-1 to 3.19 mSv y-1, with an average of 2.68 mSv y-1. The values of radium content in ce- ramic samples were found to be lower than the permissible value of 370 Bq kg-1 recommended by Organization for Eco-
nomic Cooperation and Development [19]. The used ceramic should be characterized by lower radon concentration to avoid the health hazards on human.


The authors acknowledge the financial support of the College of Science of the University of Kufa.


[1] UNSCEAR. United Scientific Committee on the Effects of Atomic Radiation, The 2000 Report to the General Assembly with Scientific Annexes. New York: United Nations 2000.

[2] European Commission (EC), Radiation Protection Unit. Radiological protec- tion principles concerning the natural radioactivity of building materials, Ra- diation Protection, 112. Luxembourg.

[3] World Health Organization, WHO handbook on indoor radon: a public

IJSER © 2014

International Journal of Scientific & Engineering Research, Volume 5, Issue 1, January-2014 2164

ISSN 2229-5518

health perspective edited by Hajo Zeeb, Ferid Shannoun, 2009. Geneva, Swit- zerland.

[4] BEIRVI (Report of the Committee on the Biological effects of Ionizing Radia- tion), Natl. Res. Council. Natl. Acad. Press, Washington, DC (1999).

[5] Almayahi, B. A., Tajuddin, A. A., Jaafar, M.S, 2011. In-Situ radon level meas- urement for a tropical country. Proceedings of International Conference on Chemical, Biological and Environment Sciences (ICCEBS' 2011) in Thailand,


[6] Almayahi, B. A., Tajuddin, A. A., Jaafar, M.S, 2012a. 210Pb, 235U, 137Cs, 40K, and 222Rn concentrations in soil samples after 2010 Thai and Malaysian floods. Advan. Biomed. Engin. 6, 593-598.

[7] Almayahi, B. A., Tajuddin, A. A., Jaafar, M.S., 2012b. Measurements of alpha emission rates in bones using CR-39 track detector. Proceedings of 2nd Inter- national Conference on Ecological, Environmental and Biological Sciences (EEBS'2012), October 13-14, 2012 at Bali (Indonesia).

[8] Almayahi, B. A., Tajuddin, A. A., Jaafar, M.S., 2012c. Measurements of natu- rally occurring 210Pb concentration in animals bones of Northern Malaysian Peninsula. Proceedings of International Conference on Agriculture, Chemical and Environmental Sciences (ICACES'2012) October 6-7, 2012 at Dubai (UAE), 189-191.

[9] Almayahi, B. A., Tajuddin, A. A., Jaafar, M.S., 2014d, Radiobiological long- term accumulation of environmental alpha radioactivity in extracted human teeth and animal bones in Malaysia. Environmental Radioactivity. (In press)

[10] Ali K. Alsaedi, B.A. Almayahi, A.H. Alasadi, 2013, Cement 222Rn and 226Ra concentration measurements in selected samples from different companies. Asian Journal of Natural & Applied Sciences (AJSC), 2, 4, 95-100.

[11] Myrick T., Berven B., Haywood F. Determination of concentrations of selected radionuclides in surface soil in the U.S. Health Phys 1983, 45: 631-642.

[12] Mayya, Y. S., Eappen, K. P., Nambi, K. S., 1998. Methodology for mixed field inhalation in monazite areas using a twin-cup dosimeter with three-track de- tector. Radiat Prot Dosim, 77, 177–184.

[13] Mahur AK, Khan MS, Naqvi AH, Prasad R, Azam A (2008). Measurement of effective radium content of sand samples collected from Chhatrapur beach, Orissa, India using track etch technique. Radiat Meas 43, S520–S522

[14] Khan MS, Zubair M, Verma D, Naqvi AH, Azam A, Bhardwaj MK (2011) The study of indoor radon in the urban dwellings using plastic track detectors. Environ Earth Sci 63:279–282.

[15] Grasty R. Geophysics 1997, 62: 1379–1385.

[16] UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiation), 2009. Annex E. Sources-to-Effects Assessment for Radon in Home sand Work- places. United Nations, New York, NY.

[17] EPA (United States Environmental Protection Agency), 2010.ACitizen′s

Guide to Radon. Retrieved 2012-01-29.

[18] ICRP (International Commission on Radiological Protection), 2012. Radiologi- cal Protection Against Radon Exposure. ICRP Publication. Ann. ICRP Ref.

4829- 9671-6554.

[19] OECD, 1979. Report by a Group of Experts of the OECD, Nuclear Energy

Agency. OECD, Paris, France.

IJSER © 2014