International Journal of Scientific Research Engineering & Technology (IJSRET)
Volume 2 Issue1 pp 012-0018 April 2013
www.ijsret.org
ISSN 2278 - 0882
Radon level and radon effective dose rate determination
using CR-39 in public hospitals – Iraq1
Kurdistan Region
(1)
Zakariya A. Hussein(1)* , Mohamad S. Jaafar(1), and Asaad H. Ismail(2)*
Radiation and Medical Physics, School of Physics, Universiti Sains Malaysia, 11800, Pulau Penang, Malaysia
(2)
Medical Physics, Physics Department, Education College, Salahaddin University-Erbil, 44002, Iraqi Kurdistan, IRAQ
*Corresponding authors: zekishtayin@yahoo.com
Abstract
Environmental radiation exists as a consequence of
cosmic, terrestrial and manmade sources. The
measurements of radon concentration inside 8 public
hospitals in the three main governorates: Erbil, Duhok
and Sulaymaniya in Iraqi Kurdistan Region, during two
season spring and autumn by using CR-39 nuclear track
detectors. The highest average radon concentration and
annual effective dose was found in the Shaheed Dr.Aso
hospital
(Sulaymaniya)
in
autumn
season
-3
(106.92±4.63Bq.m , 2.47±0.05 mSv/y ) respectively ,
and the lowest was found in the Erbil Teaching hospital
(Erbil) in spring season (48.02±3.77 Bq.m-3, 48.02±3.77
mSv/y ) respectively, this depended on the geological
formation , type of building material, ventilation rate
and the floor level. Therefore, the results showed that the
average radon concentration and annual effective dose
decreases gradually as the floor level increases. The
highest and lowest of annual effective dose was found in
ground and second floor, respectively. Comparing these
values to the Ionizing Radiation Regulations (IRR)
values which indicate that the estimated effective doses
for workers in these hospitals are less than the average
overall radon dose.
Key words: CR-39NTDs, Indoor radon, lung cancer,
ventilation and hospitals
1. Introduction
Inhalation of radon and its decay products is
responsible of about half of the annual average effective
dose received by the human due to natural sources of
radiation [1]. Outdoor radon do not represent a
significant health hazard because high concentrations are
never reached. However, it becomes a problem when
released into a closed or poorly ventilated enclosures
like dwellings, buildings and also caves and mines.
Indoor concentrations of radon and its short-lived
progeny depend on several factors mainly related with
the entry or production rate from various sources and the
ventilation rate [2]. Radon (222Rn) is a radioactive noble
gas emitted by the decay of226Ra, an element of the 238U
decay series. Radon-222 decays into a series of other
radioactive elements, of which 214Po and 218Po are the
most significant, as they contribute the majority of
radiation dose when inhaled. Following a number of
decay series, 218Po transforms into 210Po and it decays
into stable 206Pb. The 222Rn and its decay products are
reported as major causes of lung cancer [3-4].
Assessment of health effects due to exposure to ionizing
radiation from natural sources requires knowledge of its
distribution in the environment. The estimated global
average annual dose of the population receiving natural
radiation equals 2.4 mSv [5]. It is well established that
the inhalation of radon (222Rn) and mainly its radioactive
decay products, contributes more than 50% of the total
radiation dose to the world population from natural
sources [6]. The main natural sources of indoor radon are
soil, building materials (sand, rocks, cement, etc.), water
born transport, natural energy sources like (gas, coal,
etc.) which contain traces of U-238 [7-8]. The half-life
of radon, 3.8 days, is long enough for part of it to diffuse
from the indoor radon sources to the inside of the room
[9]. Therefore, in the present study, beside of measure
indoor radon concentration and annual effective dose, we
have measure most of important that related to estimate a
risks of inhalation of radon gas by the workers inside the
hospitals. As well as, and to find variation in radon
concentration for three floors ground, first, and second.
2. Materials and methods
Iraqi Kurdistan region consist of three main
governorates; Erbil, Duhok and Sulaymaniya. These
IJSRET @ 2013
International Journal of Scientific Research Engineering & Technology (IJSRET)
Volume 2 Issue1 pp 012-0018 April 2013
www.ijsret.org
areas are different from each other geographical location
is shown in Fig. 1. Passive radon dosimeter geometry is
a closed-opened chamber into which radon diffuses, and
it has been calibrated by Ismail and Jaafar [9]. The
schematic diagram of the chamber is shown in Fig. 2.
The technique used in this survey is based on CR39NTDs (Moulding, UK, manufactures the detectors), it
has area of 1.5×1.5 cm2 which is fixed by double-stick
tape at the bottom of the dosimeter. In the cover there is
a hole covered with a 5-mm thick soft sponge. The
design of the chamber ensures that all aerosols and radon
decay products are deposited on the soft sponge from the
outside and that only radon gas. The design of the
chamber ensures that the aerosol particles and radon
decay products are deposited on the sponge from outside
and only radon, among other gases, diffuses through it to
the sensitive volume of the chamber. The dosimeters
were distributed inside 8 public hospitals in three main
regions (Erbil, Duhok and Sulaymaniya) in Iraqi
Kurdistan region, in each hospital distributed on three
floors (ground, first and second). Nuclear track detector
type CR-39 (CR-39NTDs) used to measure track density
of alpha particles that emitted from radon and its
progeny. During for two seasons spring and autumn,144
pair of exposure chambers (opened-closed chamber)
equipped with 288 pieces of CR-39NTDs installed inside
72 rooms for three floors ; 3 rooms in each floor, on the
top about 2m above the floor. After for each season (90
day) of exposure, exposed detectors etched in 6N NaOH
at 70 ◦C for 10 h. The counting of alpha damage tracks
was done using an optical microscope with a
magnification of 400X was used.
3- Results and discussion
Average value of indoor radon concentration (CRn)
and annual effective dose (HE) inside public hospitals in
Iraqi Kurdistan Region for two seasons spring and
autumn summarized in Table 1. The highest indoor
radon concentration and annual effective dose was
found in autumn season in Shahid Dr.Aso hospital
(106.92±4.63 Bq.m-3 , 2.47±0.05 mSv/y ) respectively,
and lowest was found in spring season in Erbil Teaching
hospital (48.02±3.77 Bq.m-3 ,1.54±0.105 mSv/y )
respectively, as shown in Fig.3 and Fig.4 . However, it
was observed that the values are much lower than the
action levels recommended by the International
Commission on Radiological Protection (ICRP) [4]. The
seasonal variation of radon levels could be attributed to
the meteorological conditions, since in autumn, these
ISSN 2278 - 0882
dwellings were poorly ventilated to save energy but they
had good ventilation in spring time. This refers to the
different building material, ventilation rate, and the
geological formation. The geological formation of Erbil
governorate different than the geological formation of
Duhok and Sulaymaniya . More details about geological
formation are listed in Table 2 [10]. Table 3 shows the
maximum and minimum radon concentration and annual
effective dose for each level. The highest average radon
concentration was found in ground floor in autumn
season in the Shaheed Dr.Aso hospital ( 114.89±1.94
Bq. m-3) and lowest was found in second floor in spring
season in the Rizgary Teaching hospital (47.4±2.61 Bq.
m-3) , as shown in Fig.5. The combination relation of
annual effective dose in different floors in spring and
autumn seasons shows in Fig.6 . Average indoor radon
concentration decreases as the floor level increases, this
due to the reduced effect of radon exhalations from the
ground. This variation may be attributed to how close or
how far the floor is from ground since soil represents the
main source of indoor radon. In addition, many other
reasons such as the fact that upper floors are better
ventilated than lower floors that are exposed to dust and
other forms of contaminations.
4- Conclusion
Indoor radon concentrations have been measured
inside public hospitals in Iraqi Kurdistan region in two
seasons’ spring and autumn. Floor levels and geological
formation of the Iraqi Kurdistan hospitals affect on the
concentrations of indoor radon and its progeny locations
of the selected hospitals had different geological
formation and located in three main governorates: Erbil,
Duhok and Sulaymaniya. The effect of the geological
formation on indoor radon concentration and this has
been investigated. The highest radon concentration was
found in autumn in the Shaheed Dr. Aso hospital
(Sulaymaniya city: mountain region) and lowest in
spring in the Erbil Teaching hospital (Erbil city: plains
region). The average radon concentration and annual
effective dose decreases gradually as the floor level
increases. The highest and lowest of annual effective
dose was found in ground and second floor, respectively.
Acknowledgement
The authors deeply thank all the staffs and patients in
selected hospitals in Iraqi Kurdistan for their information
and a good cooperation.
IJSRET @ 2013
International Journal of Scientific Research Engineering & Technology (IJSRET)
Volume 2 Issue1 pp 012-0018 April 2013
www.ijsret.org
ISSN 2278 - 0882
Reference
6- 6- Ismail A H and Jaafar M S. (2010). Indoor
radon concentration and its health risks in
selected locations in Iraqi Kurdistan using CR39 NTDs. The 4th International conference on
Bioinformations and Biomedical Engineering
(iCBBE 2010) . 18-20 June. Chengdu-Chaina.
©2010 IEEE
1- United Nations Scientific Committee on the
effects of Atomic Radiation UNSCEAR 2000
Report to the General Assembly with Annexes,
New York, vol. 1: Sources, United Nations
Publication, Sales No. E.00.IX.4. New York,
2000.
2- Commission Recommendation of 21 February
1990 on the protection of the public against
indoor exposure to radon (90/143/EURATOM).
7- 7- Banman, A., Hervat, D.J., Lokobauer, N.,
1982. In Vahra, K.J. et al. (Eds.), Natural
Radiation Environment. WillyRastern Ltd, New
Delhi, p. 401.
3- International
Commission
on
Radiation
Protection (ICRP), 1987. Lung Cancer Risk
from Indoor Exposure to Radon Daugthers
Oxford. ICRP Publication. 50 17(1).
8- 8- Bigu, J., Vandrish, G., 1986. Environ. Monit.
Assess 6, 59–70
9- 9- Steinhausler, F., 1992. Radon in the human
environment a global approach. Proceedings of
the Eighth IRPA Congress, Montreal, Canada,
pp. 1549–1552.
4- International Commission on Radiological
Protection ICRP, (1984). Non-stochastic Effects
of Irradiation. ICRP Publication 41. Ann. ICRP.
14.
10- 10- Kamal H. K. and
Ali M.S.,(2004).
Geological formation in Iraqi Kurdistan : (KAJ)
Kurdistan Academicians Journal, 4(1) part A p.
19-39.
5- Ismail A H and Jaafar M S. (2011). Interaction
of low-intensity nuclear radiation dose with the
human blood: Using the new technique of CR39NTDs for an in vitro study. Applied Radiation
and Isotopes. 69(3) p.559-566.
Table (1) Indoor Radon Concertration and Annual Effective dose inside hospitals in Iraqi Kurdistan
Region.
Annual Effective Dose
Radon Concentration (Bq/ m 3 )
(mSv/y)
Regions
Hospital
Spring
Autumn
Spring
Autumn
Erbil
Duhok
Sulaymaniya
Rizgary
54.04±6.08
80.52±5.46
Emergency west
52.3±4.39
73.07±4.55
Erbil Teaching
48.02±3.77
69.54±4.97
Paediatric
60.38±6.34
85.42±5.6
Azadi Teaching
65.36±5.07
98.80±5.50
Emergency Teaching
59.05±4.49
80.006±8.94
Shahid Dr. Aso
71.09±4.3
110.08±4.86
Shorsh General
67.56±4.05
106.92±4.63
IJSRET @ 2013
1.19±0.13
1.16±0.07
1.1±0.08
1.38±0.14
1.52±0.125
1.34±0.122
1.64±0.07
1.54±0.09
1.77±0.11
1.62±0.08
1.54±0.105
1.95±0.13
2.36±0.05
1.82±0.27
2.56±0.12
2.47±0.05
International Journal of Scientific Research Engineering & Technology (IJSRET)
Volume 2 Issue1 pp 012-0018 April 2013
www.ijsret.org
ISSN 2278 - 0882
Table 2: Geological formation of Iraqi Kurdistan region as related to the case study
Regions
Hospital
Rizgary
Erbil
Emergency west
Equilibrium Factor (F)
Region consists of the plains and hills . It consists
of sandstone, limestone and shale
Erbil Teaching
Paediatric
Azadi Teaching
Duhok
Emergency Teaching
Shahid Dr. Aso
Sulaymaniya
Shorsh General
Region consists of the plains, sediment logical and
mountains. It consists of marly limestone,
calcarenite shale, sandly limestone and
conglomerate
Region consists of the Rocky Mountains and
valleys. It consists of rocks, limestone,
conglomerate, biogenic limestone, pebbly,
calcarenite and sandstone
Building materials
clay brick, cement
concrete, gypsum
and gypsum bord
clay brick
slimestone bricks ,
cement gypsum
and gypsum bord
clay brick
slimestone bricks
and cement
concrete gypsum
Table (3) Indoor radon concentration and Annual effective dose for different floors in
inside hospitals in Iraqi Kurdistan Region.
Hospitals
Rizgary
(Erbil)
Azadi
Teaching
(Duhok)
Radon Concentration
(Bq/m3)
Annual Effective dose
(mSv/y)
Spring
Spring
1.3±0.02
Autumn
1.89±0.01
1.24±0.04
1.77±0.03
1.04±0.05
1.66±0.05
Ground 70.22±0.38 104.21±2.005 1.65±0.12
2.41±0.11
Levels
Autumn
Ground 59.34±2.23 86.17±2.03
First
55.39±2.05 80.15±1.99
Second 47.4±2.61 75.25±2.06
First
65.79±0.42 98.99±2.39
1.51±0.096 2.39±0.18
Second
60.09±0.32 93.21±1.95
1.42±0.089 2.30±0.06
Ground 75.53±0.41 114.89±1.94
Shahid Dr.
Aso
First
70.82±0.77 110.2±1.99
(Sulaymany)
Second 66.94±0.71 105.16±2.06
1.72±0.01
2.68±0.06
1.64±0.03
1.57±0.04
2.56±0.05
2.44±0.01
IJSRET @ 2013
International Journal of Scientific Research Engineering & Technology (IJSRET)
Volume 2 Issue1 pp 012-0018 April 2013
www.ijsret.org
ISSN 2278 - 0882
Sponge membrane
Hole
1cm
h=7cm
CR-39
r=3cm
Fig.2: Schematic diagram of the optimum
Radon.
Radon Concentration (Bq/m3)
Fig.1: Sketch Map of the area under study (Kurdistan
Region)
Spring
Autumn
120
100
80
60
40
20
0
Hospitals
Fig. (3) Measurement of indoor radon concentration in spring and autumn inside public hospitals in Iraqi Kurdistan Region
IJSRET @ 2013
International Journal of Scientific Research Engineering & Technology (IJSRET)
Annual Effective dose (mSv/y)
Volume 2 Issue1 pp 012-0018 April 2013
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3
ISSN 2278 - 0882
Spring
Autumn
2.5
2
1.5
1
0.5
0
Hospitals
Radon Concentration (Bq/m3)
Fig. (4) Measurement of Annual effective dose in spring and autumn inside public hospitals in Iraqi Kurdistan Region
Spring
Autumn
120
100
80
60
40
20
0
Ground
First
Second
Floors
Fig. (5) Variation of Radon Concentration with floor levels in spring and autumn seasons in Shaheed Dr. Aso hospital
IJSRET @ 2013
International Journal of Scientific Research Engineering & Technology (IJSRET)
Annual Effective dose (mSv/y)
Volume 2 Issue1 pp 012-0018 April 2013
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ISSN 2278 - 0882
Spring
Autumn
3
2.5
2
1.5
1
0.5
0
Ground
First
Second
Floors
Fig. (6) Variation of Annual Effective dose with floor level in spring and autumn seasons in Shaheed Dr. Aso hospital
IJSRET @ 2013