Concentration level of 210Po and 210Pb in the tissues of cockle Anadara granosa from the west coast

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Concentration level of 210Po and 210Pb in the
tissues of cockle (Anadara granosa) from the west
coast of Peninsular Malaysia

• Che Abd Rahim Mohamed
•  
• Program of Marine Science
• School of Environmental Science and Natural
  Resources
• Faculty of Science and Technology
• Universiti Kebangsaan Malaysia
• 43600 Bangi, Selangor
• Malaysia
•  E-mail carmohd_at_pkrisc.cc.ukm.my

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URANIUM-THORIUM DECAY SERIES
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INTRODUCTION
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INTRODUCTION
210Po 210Pb

• Natural radioactive decay 222Rn gas, 226Ra
  solution
• Wet dry atmospheric deposition of 210Bi, 210Pb
  210Po

• In situ decay of 226Ra in water column
  atmospheric gaseous, 222Rn.
• Atmospheric fallout in shallow water.

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Source of Radionuclide

• Nature activities processes in soil, forest,
  mountain, atmosphere, lake, river and ocean
• Human activities nuclear power station, coal
  power station, etc.

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Source of radionuclide in Malaysia

• Nature processes in river, soil, lake, forest,
  atmosphere or estuary
• Human activities such as coal electric power
  station, tin mining, petroleum industry

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Radioactivity in seafood due to natural sources
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Objective

• Observe the level of natural radionuclides
  especially 210Po and 210Pb in marine organisms
  such cockle (Anadara granosa) as indicator for
  bio-isotope.
• Baseline information for Malaysian agency
  authoritative.

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Blood CockleAnadara granosaFamily ArcidaeAn
important bivalve found in muddy areas. It is
farmed in coastal Malaysia and Thailand, but is
not common locally. The red pigment in Anadara is
hemoglobin, similar to that in human blood.
Outbreaks of cholera, hepatitis A and
dysenteric shellfish poisoning have been linked
to consumption of contaminated cockles. (Length
3cm). About the pea crab that is often found
inside the blood cockle
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Biology of Cockle
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Sampling

• Samples sampling were conducted at three time as
• August 2001
• April 2002
• September 2002

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Sampling stations

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Sampling Area
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Cockle tissue samples

• Measure dry or wet weight of
• Cockle tissue
• Mixed acids (HNO3 H2O2 HClO4 HCl) and 209Po
  (chemical yield) were added
• Sample and liquid was heated until dryness
• Residue re-dissolved in 0.5M HCl ascorbic acid
• Po was deposited onto silver disc
• Count 210Po with a-spectrometry(EG G, ORTEC)
• (Twice measurement was taken. After gt3 month
  210Pb was taken)

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Results and Discussion
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In generally, high radioactivity concentration
were found in dried sample.
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Relationship between concentration of
radionuclides with dry weight of cockles tissue
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Table 2. Average concentration of 210Po and
210Pb in organisms from different researchers in
other countries.
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Status concentration level of 210Po and 210Pb in
Malaysian waters

• More radionuclide concentration was reported on
  Mytilus sp as Bio-isotope but limited information
  or published on Anadara granosa, especially in
  Malaysian waters.
• Low levels of 210Po and 210Pb were found in the
  Anadara granosa different time and size.
• Concentration level of both nuclides were
  slightly low compared with other countries
  indicating as natural sources.
• Range ratio of 210Po/210Pb was from 0.93 to 6.41
  indicating a large part of 210Po in each
  individual specimen comes from the local
  environment, where the ranging ratio of
  210Po/210Pb in suspended solid at study area was
  0.34 to 8.38 (Lee Mohamed, in-press).

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Conclusions

• Anadara granosa also a suitable biological
  species as indicator for bio-isotope.
• Low concentration level of 210Po and 210Pb, and
  210Po/210Pb was found in the Anadara granosa
  tissue.

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ACKNOWLEDMENTS

• This research was supported by the Grant IRPA
  09-02-02-0045-EA141
• Special Thanks To
• JSPS especially to Prof. Dr. Nobuyuki Miyazaki
• Ocean Research Institute, The University of Tokyo
• Dr. Zaharudin Bin Ahmad
• Malaysian Institute for Nuclear Technology
  Research (MINT)
• Research Assistant, Graduate Students
  Laboratory Assistants of Oceanography Laboratory,
  Universiti Kebangsaan Malaysia (UKM)

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