Content uploaded by Che Abd Rahim Mohamed
Author content
All content in this area was uploaded by Che Abd Rahim Mohamed on Oct 31, 2019
Content may be subject to copyright.
34
In-house Seminar of Chemical Oceanography
(Issue 1, Vol I)
3/2016, ISSN 0127-9629
A Preliminary Study on the Activity of 210Po
in the Drinking Water Supply Chain
Minhaz Farid Ahmed, Lubna Alam*, Goh Choo Ta, Che Abd Rahim Mohamed and Mazlin Mokhtar
Institute for Environment and Development (LESTARI),
School of Environmental and Natural Resource Sciences,
Universiti Kebangsaan Malaysia (UKM), 43600 UKM Bangi, Selangor, Malaysia.
Phone: 038921 7656 *corresponding author's email: lubna@ukm.edu.my
ABSTRACT
210Po is highly toxic and it is naturally abundant in
water. Although rivers are seriously polluted both by the
natural and anthropogenic sources in Malaysia;
however it is the main source of drinking water.
Therefore, river water, treated water from the outlet of
water treatment plant and supplied/tap water at the
household level in the Langat River Basin were analyzed
by the Alpha-particle Spectrometry. The activity of 210Po
in the river water i.e. 7.7 × 10-3 Bq/L was a little bit
higher than other studies conducted in and out of
Malaysia. Similarly, the activity of 210Po in the supplied
water and its annual effective dose were 1.7 ×10-3 Bq/L
and 1.5 × 10-3 mSv/year, respectively. However, the
activity of 210Po in the treated water at outlet of water
treatment plant was 1.5 × 10-3 Bq/L. Though the activity
and annual effective dose from 210Po were within the
maximum limit set by Ministry of Health, Malaysia and
World Health Organization, however, it is higher than
many other countries of the world. Therefore, further
study is required to determine the status of 210Po largely
in the drinking water supply chain of Malaysia to
identify its impact on human health.
Keywords: Drinking Water, 210Po, Radioactivity,
Annual Effective Dose, Carcinogenic.
I.
INTRODUCTION
210Po is a naturally occurring radionuclides and it is
largely found in water, soil and food. Therefore, human
beings are at risk of ingestion of 210Po through drinking
water and its annual effective doses for a long time.
Moreover, 210Po is considered as one of the main sources
of alpha [1] exposure to human being through ingestion
of drinking water [2]. 210Po is about 250 000 times more
toxic than hydrogen cyanide [1]. Therefore, it is
considered carcinogenic if ingested through drinking
water and it damages organic tissues such as the spleen,
liver, kidney, lung, etc. [1; 3].
Natural sources contribute about 80% to
generate radionuclides in Malaysia and the other sources
are anthropogenic such as industrial activities as well as
mining of natural resources along with gas and
petroleum exploration [4]. Many studies in the
Peninsular Malaysia investigated the existence of the
radioactivity of 226Ra, 228Ra, 210Pb, 137Cs, 232Th, 40K and
222Rn in water body [5; 2; 6; 7; 8] and it was reported
that about 87% radioactivity exposed by human being in
Peninsular are mainly from the natural sources [2].
Moreover, atmospheric source is also considered as one
of the sources of 210Po in water because of the decay of
222Rn gas and the decay of naturally occurring 238U [1].
Therefore, 222Rn is also considered as one of the major
sources of increased 210Po and 210Pb activity in the
human being [2; 37].
The application of 210Po in industrial sector is
wide and it largely used in paper rolling, producing
plastic sheets, spinning synthetic fibers, producing
neutron initiator as well as producing energy through
thermoelectric devices [1]. However, in Malaysia mainly
river water is treated for drinking purpose and the river
provides about 95% to 98% raw water of drinking
requirement [9; 10], but these rivers are highly polluted
by the industrial sectors [11]. Overall in Malaysia
manufacturing industrial is responsible of 0.31% in
polluting the rivers, but in case of Langat River
industrial sector and mining activities were responsible
of 9.09% and 0.24% respectively [12]. Moreover, 414
polluter industries in Selangor, which was maximum
among the States of Malaysia, significantly contributes
in the contamination of river [11]. Although Langat
River is the main source of drinking water of the two-
third populations in the State Selangor [13; 14],
however, it is contaminated with chemicals both by the
natural and anthropogenic sources [37].
There were only a few studies on the
radioactivity of radionuclides in the drinking water of
Malaysia. For instance, the drinking water of Johor
Bahru, Malaysia was investigated in terms of the
radioactivity of 238U, 232Th, and 40K using the gamma-
ray spectroscopy and the activities were determined
18.2±1.5 × 10-3 Bq/L, 38.9±3.4 × 10-3 Bq/L and
1220±50 × 10-3 Bq/L respectively (Table 1). However,
the activity of these radionuclides was much below the
standard of Ministry of Health, Malaysia i.e. 0.1 Bq/L
for alpha emitter and 1 Bq/L for gamma emitter
respectively [15; 22]. Moreover, the standard range of
Potassium i.e. (570±210 to 34080±5610) × 10-3 Bq/L
was also set by WHO [15].
35
Table 1: Radioactivity of Radionuclides in Drinking Water of
Johor Bahru, Malaysia.
Radionuclides
Radioactivity
(Bq/L ×10-3)
Annual Effective
Dose (mSv/year ×
10-9)
238U
232Th
40K
18.2±1.5
38.9±3.4
1220±50
1.5±0.100
0.122±1.10
5530±0.023
Source: [15]
Accordingly, the annual effective doses of 238U,
232Th, and 40K were reported 1.5±0.1 × 10-9 mSv/year,
0.122±1.1 × 10-9 mSv/year, 5530±0.23 × 10-9 mSv/year,
respectively. However, the annual effective doses of
these radionuclides were very negligible, as the standard
set by the United Nations Scientific Committee on
Effects of Atomic Radiation (UNSCEAR) in 2000 was
0.12 mSv/year and it is also the global average value of
annual effective doses from the radionuclides [15].
Similarly, the activity of 238U, 232Th and 40K in
the drinking water was investigated (1.3±8)×10¯4 Bq/Kg,
(5.75±8)×10¯4 Bq/Kg, and (6.18±6)×10¯4 Bq/Kg,
respectively in the middle part of Peninsular Malaysia.
However, these activities of the radionuclides were
much below the standard of UNSCEAR (2000) [8], but
specific area of the WTPs to supply drinking water in the
basin.
Source: [36]
Figure 1: Langat River Basin in Peninsular Malaysia.
The analysis of 210Po followed the modified method of
IAEA (International Atomic Energy Agency) for the
FeOH3 precipitation [18]. Moreover, the activity
concentration of 210Po in water samples was determined
by alpha-particle spectrometry.
The following equitation has been used to
210
in some places of Malaysia the activity of 226Ra i.e. 0.30 calculate the activity of Po:
Bq/L in drinking water was recorded above the standard
set by United States Environmental Protection Agency.
Moreover, the range of annual effective doses from
radionuclides in some places of Malaysia were
determined 0.02 mSv/year to 0.06 mSv/year [16; 37].
Although there is no significant study of 210Po
in the drinking water supply chain of Malaysia, but it’s
an urgency to study the activity of 210Po in drinking
water because of its high radio-toxicity. As Langat
River, main source of drinking water in Selangor state, is
highly polluted both by the natural and anthropogenic
sources, so determining the activity of 210Po in the
drinking water and its annual effective dose to human
being is very important in terms of health hazards.
Therefore, the study investigated the activity of 210Po in
the drinking water of Langat River Basin and the annual
effective dose through ingestion of drinking water.
II. MATERIALS AND
METHOD
Twenty liter water samples were collected in
polyethylene container from the Langat River at Hulu
Langat, Langat Water Treatment Plant at Hulu Langat
and Supplied/Tap water at Bangi, Malaysia (Figure 1).
There are a total nine Water Treatment Plants (WTPs) in
the Langat River Basin and these nine WTPs provide
drinking water to the 50% populations in Selangor State
[17] through the water distributor SYABAS (Syarikat
Bekalan Air Selangor Sdn Bhd). However, there is no
Activity of 210Po = [cpm (sample)/ cpm (tracer)] × [Mass of
tracer × (dpm/g)] × [1/ Volume of sample]…… (1)
Source: [19]
The annual effective dose to an individual due
to ingestion of radionuclides from the water sample was
assessed using the following equitation:
Dw = Cw × CRw × Dcw ………………
(2)
Source: [20; 15]
Here,
Dw = Annual effective dose (mSv/year) (i.e. Ingestion of
radionuclides through drinking water)
Cw = Activity of radionuclides in the ingested water
(Bq/L)
CRw = Annual intake of drinking water
(i.e. Age > 17 year; 2 Liter/day, so 731 Litre/year in
Malaysia) [15]
Dcw = Ingested dose conversion factor for 210Po is 1.2 ×
10−3 mSv/ Bq based on the report of ICRP 1996 [21]
36
Location
Sample
Vol.(L)
210Po (Bq/L × 10-3)
Langat River,
Hulu Langat
Langat WTP1,
Hulu Langat
Supply Water,
Bangi
River
Water
Treated
Water
Tap
Water
20
20
20
7.7±0.6
1.5±0.2
1.7±0.3
Location
210Po (Bq/L × 10-3)
Minimum
Maximum
Langat River,
Malaysia2
(2015)
7.7±0.6
-
Kuala Selangor
River, Malaysia
(2005) [24]
0.223±0.065
0.753±0.28
Kuala Selangor
River, Malaysia
(2010) [19]
Tagus River,
Portugal (1997)
[25]
0.00018±0.00012
0.5±0.36
0.01383±0.00262
0.67±0.03
III. RESULTS AND
DISCUSSION
The activity of 210Po in the river water, treated water and
tap water at household level was calculated 7.7 × 10-3
Bq/L, 1.5 × 10-3 Bq/L and 1.7 × 10-3 Bq/L (Table 2)
respectively, based on the equitation (1) which was
much below the standard set by Ministry of Health,
Malaysia i.e. 0.1 Bq/L for alpha emitter [22] and the
World Health Organization i.e. 0.5 Bq/L for alpha
emitter [23].
Table 2: Activity of 210Po in Drinking Water Supply Chain at
Langat River Basin, Malaysia.
It was observed that the radioactivity of 210Po in
the supplied water i.e. 1.7 × 10-3 Bq/L is slightly higher
than the activity of the treated water i.e. 1.5 × 10-3 Bq/L
at the outlet of water treatment plant might be due to the
contamination in the pipeline of drinking water supply
system (Table 2). Moreover, the activity of 210Po in the
supplied water in Malaysia is higher than many countries
of the world such as 1 × 10-3 Bq/L in Italy (2007) [26],
1.01 × 10-3 in Hungary (2009) [27], 0.48 × 10-3 Bq/L in
Poland (2001) [28], 1.4 × 10-3 Bq/L in India (2001) [29],
1 × 10-3 Bq/L in Brazil (1992) [29], 0.21 × 10-3 Bq/L in
Portugal (1995) [29], 1 × 10-3 Bq/L in Syria (1995) [29],
0.4 × 10-3 Bq/L in Austria (2001) [30], etc. On the other
hand, the activity of 210Po in the supplied water of USA
(2008) i.e. 5 × 10-3 Bq/L [31], Italy (2009) i.e. 3.25 × 10-
3 Bq/L [23] and Bombay, India (1977) i.e. 1.9 × 10-3
Bq/L [29] were higher than the activity of 210Po in the
supplied water of Malaysia, 2015 (Figure 2) [37].
However, the study found the concentration of
210Po in the river water higher than some other studies in
and out of Malaysia. The radioactivity of 210Po in the
Langat River was 7.7 × 10-3 Bq/L in 2015, whereas, the
activity of it in Kuala Selangor river was in the range of
(0.223-0.753) × 10-3 Bq/L and (0.00018-0.01383)×10-3
Bq/L in 2005 and 2010 respectively (Table 3). Similarly,
the activity of 210Po in the Langat River, Malaysia was
higher than the activity of Tagus River, Portugal (1997)
i.e. in the range of (0.5-0.67) × 10-3 Bq/L might be due
to the pollution of Langat River both from the natural
Figure 2: Comparing
Water.
210Po (Bq/L × 10
-3) Activity in Drinking
and anthropogenic sources [17].
Table 3: Activity of 210Po in different Rivers.
Similarly, the estimated annual effective dose
of 210Po through ingestion of drinking water is 1.5 × 10-3
mSv/year (Figure 3) based on the equitation (2) which is
lower than the standard 0.12 mSv/year set by the United
Nations Scientific Committee on Effects of Atomic
Radiation (UNSCAER), 0.01 mSv/year set by the World
Health Organization (WHO), 1.0 mSv/year set by the
International Commission on Radiological Protection
(ICRP) [15] and 0.01 mSv/year set by the Polish
Ministry of Health [32].
The annual effective doses
from
210Po,
228
Ra,
1 WTP= Water Treatment Plant
2 Present Study 2015
210Pb and 226Ra through ingestion of drinking water are
significant in terms of dose contributions. Although the
radioactivity of 210Po in drinking water is lower than the
activity of the isotopes of Uranium, however 210Po is
considered highly toxic. Moreover, 210Po, 228Ra, 210Pb
and 226Ra are the most important dose contributors
through ingestion by the drinking water. For instance, Jia
et al. (2009) investigated that the mean radioactivity of
210Po i.e. 3.25 × 10-3 Bq/L (Figure 2) in the drinking
water. Jia et al. (2009) also reported although the activity
of 210Po in drinking water remained in the last position in
the series of 238U, 228Ra and 210Pb, however in terms of
annual effective dose i.e. 2.84 × 10-3 mSv/year
37
(Figure 3) 210Po was the highest contributor in the same
series of radionuclides. Similarly, the activity and annual
effective dose of 210Po in the drinking water of Bombay,
India (1977) were 1.9 × 10-3 Bq/L and 1.7 × 10-3
mSv/year respectively that was alike the findings of Italy
(2009) (Figure 3). Unfortunately, the activity of 210Po in
the drinking water and its annual effective dose exposure
for a long time to human being has not been studied
extensively due to its difficulties in determining the
radioactivity [37].
mSv/year
Figure 3: Comparing Annual Effective Dose from 210Po
(mSv/year ×10-3) through Ingestion of Drinking Water.
IV.
CONCLUSION
210Po is considered carcinogenic as only about 1110 Bq
(i.e. 0.03 microcurie) can be life threatening of human
being if ingested. It was reported that ingestion of 210Po
through drinking water and a long exposure of annual
effective dose from it can be responsible of cancer,
anemia, osteoporosis, cataracts, bone growths, kidney
disease, liver disease, etc. of human being [34]. 210Po is
5000 times more alpha emitter than the same volume of
radium [33] and the Minnesota Department of Health,
USA investigated obvious threat of 210Po activity on the
organic tissues of human being due to ingestion by
drinking water [35]. Therefore, further study is required
in a large scale to determine the activity of 210Po in the
drinking water supply chain and its association with the
human health risk.
ACKNOWLEDGEMENT
The study is based on the grants: GGPM-2014-010 and
FRGS/2/2014/STWN01/UKM/02/2 from the Universiti
Kebangsaan Malaysia. Therefore, the authors are
grateful to the university authority to support to conduct
the study. The authors are also grateful to the water
treatment plant authorities ‘Puncak Niaga (M) Sdn.
Bhd.’ and ‘Loji Rawatan Air Sungai Labu’ for providing
water samples from the outlet of their water treatment
plants at the Langat River Basin.
REFERENCES
[1] Alam, L. and Mohamed, C. A. R. (2010). In D. A.
Atwood (Ed.), Radionuclides in the Environment:
John Wiley & Sons Ltd, United Kingdom, 149-154.
[2] Almayahi, B.; Tajuddin, A. and Jaafar, M. (2014).
Radiation Physics and Chemistry, 97, 56-67.
[3] Jia, G.; Torri, G. and Magro, L. (2009). Journal of
Environmental Radioactivity, 100(11), 941-949.
[4] Musa. S. (2011). Radioactive Level in Malaysia Still
Safe and Low, Retrieved November 22, 2015, from
http://www.ukm.my/news/arkib/index.php/en/extra s
/689- radioactive-level-in-malaysia-still-safe- and-
low.html.
[5] Ahmad, N.; Jaafar, M.; Bakhash, S. M. and Rahim, M.
(2015). Journal of Radiation Research and Applied
Sciences, 8(1), 136-141.
[6] Almayahi, B.; Tajuddin, A. and Jaafar, M. (2012).
Applied Radiation and Isotopes, 70(11), 2652-2660.
[7] Almayahi, A. Tajuddin and M. Jaafar. (2014). Radiation
Physics and Chemistry, 97, 56-67.
[8] Tawalbeh, A.; Samat, S.; and Yasir, M. S. (2013). Sains
Malaysiana, 42(3), 319-323.
[9] Leong, K. H.; Tan, L. B. and Mustafa, A. M. (2007).
Chemosphere, 6(6), 1153-1159.
[10] Santhi, V. A.; Sakai, N.; Ahmad, E. D. and Mustafa, A.
M. (2012). Science of The Total Environment, 427, 332-
338.
[11] Muyibi, S. A.; Ambali, A. R. and Eissa, G. S. (2008).
Water Resources Management, 22(4), 485-508.
[12] DOE. (2013). Malaysia Environmental Quality Report
2013, Putrajaya, Malaysia.
[13] Alsalahi, M. A.; Latif, M. T.; Ali, M. M.; Magam, S.
M.; Wahid, N. B. A.; Khan, M. F. and Suratman. S
(2014). Marine Pollution Bulletin, 80(1), 344-350.
[14] Juahir, H.; Zain, S. M.; Yusoff, M. K.; Hanidza, T. T.;
Armi, A. M.; Toriman, M. E. and Mokhtar, M. (2011).
Environmental Monitoring and Assessment, 173 (1-4),
625-641.
[15] Yussuf, N.; Hossain, I. and Wagiran, H. (2012).
Scientific Research and Essays, 7(9), 1070-1075.
[16] Amin, Y. M.; Jemangin, M. and Mahat, R. (2010).
Perfik 2009, 409-411.
[17] Farid, A. M.; Lubna, A.; Choo, T. G.; Rahim, M. C. and
Mazlin, M. (2016). Asian Journal of Water,
Environment and Pollution, 13(1), 9-15.
[18] IAEA. (2009). A Procedure for the Determination of Po-
210 in Water Samples by Alpha Spectrometry Vienna,
Austria: International Atomic Energy Agency.
[19] Mohamed, C. A. R. and Siang, T. C. (2010). Coastal
marine science, 34(1), 186-194.
[20] Hamzah, Z.; Rahman, S. A. A.; Saat, A.; Agos, S. S. and
Ahmad, Z. (2010). Journal of Nuclear and Related
Technologies, 7(2).
[21] Jia , G. and Torri, G. (2007). Applied Radiation and
Isotopes, 65(7), 849-857.
[22] MOH. (2004). Drinking water quality standard
Retrieved February 28, 2015, from
http://kmam.moh.gov.my/public- user/drinking-
water-quality-standard.html.
[23] Jia, G.; Torri, G. and Magro, L. (2009). Journal of
Environmental Radioactivity, 100(11), 941-949.
[24] Theng, T. L. and Mohamed, C. A. R. (2005). Journal of
Environmental Radioactivity, 80(3), 273-286.
[25] Carvalho, F. P. (1997). Science of the Total
Environment, 196(2), 151-161.
[26] Desideri, D.; Meli, M.; Feduzi, L.; Roselli, C.; Rongoni
A. and Saetta, D. (2007). Journal of Environmental
Radioactivity, 94(2), 86- 97.
[27] Benedik, L.; Vasile, M.; Spasova, Y. and Wätjen, U.
(2009). Applied Radiation and Isotopes, 67(5), 770-
775.
[28] Skwarzec, B.; Strumińska, D. and Borylo. (2001).
Journal of Radioanalytical and Nuclear Chemistry,
250(2), 315-318.
32
