Displaying publications 1 - 20 of 39 in total

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  1. Esther Phillip, Muhamat Omar, Muhamad Samudi Yasir, Mohd Zaidi Ibrahim, Zalina Laili
    MyJurnal
    Effect of AP+, Ca", Cu" and Fe" on the removal of radium-226 from radium-contaminated soil using humic acid extracted from a Malaysian peat soil was investigated using batch washing method. The concentration of Al,+ Ca", Cu" and Fe" ranged from 0 to 100 ppm. The radioactivity concentration of radium-226 was determined by gamma spectrometer. The removal of radium-226 was enhanced in the presence of AP' with concentration between 20 - 60 ppm. Meanwhile, higher concentration of 80 - 100 ppm did not lead to further increase in the removal of radium-226. The removal of radium-226 was decreased in the presence of Ca" and Cu". In the presence of Fe" with concentration between 20 - 60 ppm, decrease in the removal of radium-226 was also observed. Nevertheless, at concentration between 80 - 100 ppm, the presence of Fe" led to increase in the removal of radium-226.
    Matched MeSH terms: Radioactivity
  2. Ahmad Saat, Nor Shazlina Zainal, Zaini Hamzah
    MyJurnal
    Ground water contain natural radioactivity associated with uranium and thorium that present naturally in rocks and soils. Humans may be exposed to the emission of energetic alpha particle from supported radon decaying process in this water when it is inhaled or ingested. Assessment of supported radon in ground water was carried out using fourteen ground water samples from Cameron Highlands. The measurement was accomplished by degassing the water samples using pump and then allowing the gas to flow into specially constructed 0.0191 m8 metal chamber. The activity concentration of supported radon in water sample was measured using continuous radon monitor inside the radon chamber. Measurement was carried out at one hour interval for twenty four hours. The hourly supported radon concentration was found to stabilize after about 8 hours. The stabilized concentration was used to determine supported radon activity concentration in the water samples. Results of the study show that depending on the sampling location, the activity concentrations of supported radon are in the range from 0.09 - 0.48 Bq/L which is lower than the activity concentration of radon in drinking water as proposed by USEPA (11 Bq/L).
    Matched MeSH terms: Radioactivity
  3. Asnor Azrin Sabuti, Che Abd Rahim Mohamed, Zaharudin Ahmad
    MyJurnal
    Various environmental samples (seawater, TSS, sediment, rainwater and fly ash) from eight different stations near Kapar coastal area were analyzed. The 210 Po activity concentrations in liquid samples (seawater and rainwater) varied between 0.34 ± 0.03 mBq L-1 to 22.44 ± 0.53 mBq L-1 . Whereas the concentrations in particulate samples (TSS, sediment and fly ash) varied between 43.79 ± 2.31 Bqkg-1 to 364.48 ± 5.43 Bqkg-1 . Results also showed the radioactivity in Kapar coastal is higher than most of Malaysian coast, reaching a factor of seven. This condition is mainly due to the operation of a coal-fired power plant nearby. This study also clarify the variability of 210 Po in environment was strongly influenced from rainfall events especially during wet seasons.
    Matched MeSH terms: Radioactivity
  4. Yii, Mei Wo, Zaharuddin Ahmad
    MyJurnal
    The studies of ¹³⁷Cs content in the seawater surrounding Peninsular Malaysia had been carried out as part of the Malaysia Marine Radioactivity Database Project. The results of the measurement will serve as the baseline data and reference level to Malaysia. A numbers of sampling locations, including coastal and offshore at the East Coast (South China Sea) and West Coast (Straits of Malacca) of Peninsular Malaysia had been selected for the study. From each location at the coastal area, water samples were collected from the surface of the seawater. Meanwhile, for the offshore area, water samples have been collected at three different depths. Due to usual low concentration of ¹³⁷Cs in the marine environment, large volumes of seawater were collected and the co precipitation technique was employed to concentrate the ¹³⁷Cs. The activity of ¹³⁷Cs was determined by measuring the peak area under photo peak of the gamma spectrum at 661 keV, which is equivalent to the gamma intensity corrected to the HpGe detection efficiency and percentage of gamma ray abundance of the ¹³⁴Cs. At each study location, there were no significant differences for ¹³⁷Cs activities at 95% confidence interval. The activities of ¹³⁷Cs found to be quite uniformly distributed in the range of 2.33 to 5.00 Bq/m3and 1.76 to 4.76 Bq/m3for the South China Sea and the Straits of Malacca, respectively.
    Matched MeSH terms: Radioactivity
  5. Siraz MMM, Kamal MH, Khan ZH, Alam MS, Al Mahmud J, Rashid MB, et al.
    Environ Monit Assess, 2023 Aug 10;195(9):1028.
    PMID: 37558890 DOI: 10.1007/s10661-023-11636-5
    This study marks the first-ever assessment of radiological hazards linked to the sands and rocks of Patuartek Sea Beach, situated along one of the world's longest sea beaches in Cox' Bazar of Bangladesh. Through the utilization of an HPGe detector, a comprehensive analysis of the activity concentrations of 226Ra, 232Th, and 40 K was conducted, and their activity ranged from 7 to 23 Bq/kg, 9-58 Bq/kg, and 172-340 Bq/kg, respectively, in soils, and 19-24 Bq/kg, 27-39 Bq/kg, and 340-410 Bq/kg, respectively, in rocks. Some sand samples exhibited elevated levels of 232Th, while the rock samples displayed higher levels of 40 K compared to the global average. The radiological hazard parameters were assessed, and no values surpassed the recommended limits set by several international organizations. Hence, the sands and rocks of Patuartek sea beach pose no significant radiological risk to the residents or tourists. The findings of this study provide crucial insights for the development of a radiological baseline map in the country, which is important due to the commissioning of the country's first nuclear power plant Rooppur Nuclear Power Plant. The data may also stimulate interest in the rare-earth minerals present in the area, which is important for the electronics industry, thorium-based nuclear fuel cycles.
    Matched MeSH terms: Radioactivity*
  6. Siraz MMM, A M J, Alam MS, Rashid MB, Hossain Z, Khandaker MU, et al.
    PLoS One, 2023;18(10):e0289113.
    PMID: 37856554 DOI: 10.1371/journal.pone.0289113
    This work presents the first in-depth study of soil radioactivity in the mangrove forest of Bangladesh part of the Sundarbans. It used HPGe gamma-ray spectrometry to measure the amount of natural radioactivity in soil samples from Karamjal and Harbaria sites of the world's largest mangrove forest. The activity concentrations of most of the 226Ra (14±2 Bqkg-1 to 35±4 Bqkg-1) and 232Th (30±5 Bqkg-1 to 50±9 Bqkg-1) lie within the world average values, but the 40K concentration (370± 44 Bqkg-1 to 660±72 Bqkg-1) was found to have exceeded the world average value. The evaluation of radiological hazard parameters revealed that the outdoor absorbed dose rate (maximum 73.25 nGyh-1) and outdoor annual effective dose (maximum 0.09 mSvy-1) for most samples exceeded the corresponding world average values. The elevated concentration of 40K is mainly due to the salinity intrusion, usage of fertilizers and agricultural runoff, and migration of waste effluents along the riverbanks. Being the pioneering comprehensive research on the Bangladesh side of the Sundarbans, this study forms a baseline radioactivity for the Sundarbans before the commissioning of the Rooppur Nuclear Power Plant in Bangladesh.
    Matched MeSH terms: Radioactivity*
  7. Siraz MMM, Al Mahmud J, Alam MS, Rashid MB, Hossain Z, Osman H, et al.
    Environ Monit Assess, 2024 Jan 23;196(2):192.
    PMID: 38263472 DOI: 10.1007/s10661-024-12328-4
    Miners, factory workers, traders, end-users, and foodstuff consumers all run the risk of encountering health hazards derived from the presence of elevated levels of radiation in fertilizers, as these groups often come into direct or indirect contact with fertilizers as well as raw materials throughout various linked processes such as mineral extractions, fertilizer production, agricultural practices. A total of 30 samples of various kinds of fertilizer produced in different factories in Dhaka megacity were analyzed to quantify the concentrations of primordial radionuclides using HPGe detector. Among the analyzed samples, average (range) concentration of 40K was found to be 9920 ± 1091 (8700 ± 957-11,500 ± 1265), 9100 ± 1001 (8600 ± 946-9600 ± 1056), 2565 ± 282 (2540 ± 279-2590 ± 285), and 3560 ± 392 (2620 ± 288-4500 ± 495) Bq/kg in the samples of Muriate of Potash Fertilizer, Sulphate of Potash Fertilizer, Humic Acid Fertilizer, and NPKS Fertilizer, respectively. Elevated concentration of 226Ra was found in Triple Super Phosphate Fertilizer with a mean (range) of 335 ± 37 (290 ± 32-380 ± 42) Bq/kg. The higher activity of 40K can be linked to the greater levels of elemental potassium in phosphate fertilizer. Elevated concentrations of radionuclides may also result from variations in chemical processes as well as the local geology of the mining areas where the raw materials were extracted for fertilizer production. Numerous fertilizer brands surpass prescribed limits for various hazardous parameters, presenting significant health risks to factory workers, farmers, and consumers of agricultural products. This study provides baseline information on the radioactivity of fertilizers, which could be used to develop mitigation methods, establish national fertilizer usage limits, justify regulatory frameworks, and raise public awareness of fertilizer overuse. The findings of the study could potentially help to explore the impact of fertilizer on the food chain.
    Matched MeSH terms: Radioactivity*
  8. Omar, M., Hamzah, M.S., Wood, A.K.
    MyJurnal
    A study to measure the concentrations of long-lived radionuclides of the uranium and thorium series in naturally occurring radioactive materials (NORM) wastes was carried out using gamma spectrometry and neutron activation analysis methods. It was found that radionuclides in the NORM wastes of the oil/gas production and ores/minerals processing industries were not in equilibrium. The 226 Ra/ 238 U and 228 Ra/ 232 Th ratios were between 0.001 and 2220 indicating that the concentrations of daughters radionuclides ( 226 Ra, 228 Ra) were very low or very high compared to the parent radionuclides ( 238 U, 232 Th) in the NORM wastes.
    Matched MeSH terms: Radioactivity
  9. Joel ES, Maxwell O, Adewoyin OO, Olawole OC, Arijaje TE, Embong Z, et al.
    Sci Rep, 2019 03 12;9(1):4219.
    PMID: 30862825 DOI: 10.1038/s41598-019-40884-0
    Natural radioactivity in coastaline area soil of Ado-Odo/Ota has been carried out to ascertain the presence of radionuclides using gamma-ray spectroscopy (HPGe detector). The result showed that U-238, Th-232 and K-40 ranged from 24 ± 7-49 ± 10; 67 ± 6-120 ± 9 and 88 ± 17-139 ± 20 Bqkg-1 respectively. The radium equivalent for the samples ranged from 132.51 to 230.91 Bqkg-1 with mean value of 185.89 Bqkg-1. The mean value for the gamma dose rate for the soil samples was estimated to be 81.32 nGyh-1. The estimated values of annual effective dose equivalent ranged from 0.61 to 1.07 mSv y-1. The estimation of alpha index representative (Iα) ranged from 0.12 to 0.24 with mean value of 0.21 while the gamma representative index ranged between 0.465 and 0.810. The activity utilization index of the soil samples ranged from 1.09 to 1.89 with mean value of 1.53. The radiological implication in the study area has shown that the soil samples with gamma dose rate value of 89.99 nGyh-1, 94.39 nGyh-1, 97.40 nGyh-1 and 101.04 nGyh-1 respectively are higher than the recommended value of 80 nGyh-1 and may pose health implication for long term exposure.
    Matched MeSH terms: Radioactivity
  10. Asfahani J, Samuding K, Mostapa R, Othman O
    Appl Radiat Isot, 2021 Jan;167:109296.
    PMID: 33022484 DOI: 10.1016/j.apradiso.2020.109296
    Natural gamma ray well logging technique is used to characterize the radioactivity (GR) laterally and vertically in Banting district, SW of Malaysia. Seven drilled boreholes, along N-S profile with their natural gamma ray records are utilized to compute the heat production (HP) parameter, based on the Bucker and Rybach relationship.The analysis of 3467 measured points in those boreholes indicates that GR varies between 6.24 API and 358.4 API with an average of 79.95 API, while HP varies between 0.086 and 5.65 μw/m3 with an average of 1.25 μw/m3.The multi-fractal Concentration-Number (C-N) is used to characterize the radioactivity and heat production variations and to isolate different GR and HP populations in the study region. The high radioactivity and heat production ranges are mainly related to the silty clay layers, accompanied by uranium and thorium.
    Matched MeSH terms: Radioactivity
  11. Omar, M.
    MyJurnal
    The interference of 235 U on 226 Ra concentration measured directly using the γ-ray energy of 186 keV and the interference of 228 Ac on the 40 K analysis by gamma-spectrometry system were highlighted and discussed. The interference of 235 U was demonstrated to be very significant, i.e. 45% of the 226 Ra concentration measured directly at 186 keV in natural samples containing uranium series in equilibrium. The interference of 228 Ac on 40 K concentration was particularly significant for samples containing high concentration of 228 Ac ( 228 Ra) such as radioactive minerals. Another important aspect discussed is the assignment of the right emission probability of the 583 keV and 2614 keV of the 208 Tl for the purpose of estimating the concentration of 232 Th or other radionuclides in the thorium series. Extra cautions are required in the interpretation of the measured 208 Tl concentration in samples of various natures. It is suggested that the emission probability used for 208 Tl be reported for comparison and verification.
    Matched MeSH terms: Radioactivity
  12. Alnour IA, Wagiran H, Ibrahim N, Hamzah S, Elias MS, Laili Z, et al.
    Radiat Prot Dosimetry, 2014 Jan;158(2):201-7.
    PMID: 23965286 DOI: 10.1093/rpd/nct206
    The distribution of natural radionuclides ((238)U, (232)Th and (40)K) and their radiological hazard effect in rocks collected from the state of Johor, Malaysia were determined by gamma spectroscopy using a high-purity germanium detector. The highest values of (238)U, (232)Th and (40)K activity concentrations (67±6, 85±7 and 722±18 Bg kg(-1), respectively) were observed in the granite rock. The lowest concentrations of (238)U and (232)Th (2±0.1 Bq kg(-1) for (238)U and 2±0.1 Bq kg(-1) for (232)Th) were observed in gabbro rock. The lowest concentration of (40)K (45±2 Bq kg(-1)) was detected in sandstone. The radium equivalent activity concentrations for all rock samples investigated were lower than the internationally accepted value of 370 Bq kg(-1). The highest value of radium equivalent in the present study (239±17 Bq kg(-1)) was recorded in the area of granite belonging to an acid intrusive rock geological structure. The absorbed dose rate was found to range from 4 to 112 nGy h(-1). The effective dose ranged from 5 to 138 μSv h(-1). The internal and external hazard index values were given in results lower than unity. The purpose of this study is to provide information related to radioactivity background levels and the effects of radiation on residents in the study area under investigation. Moreover, the relationships between the radioactivity levels in the rocks within the geological structure of the studied area are discussed.
    Matched MeSH terms: Radioactivity
  13. Yusof Abdullah, Mohd Reusmaazran Yusof, Azali Muhamad, Zaifol Samsu, Nurhaslinda Ee Abdullah
    MyJurnal
    Boron carbide (B4C) is a ceramic material which is effective to absorb thermal neutron due to wide neutron absorption cross section. In this work, B4C is added into concrete as fine aggregates to test the attenuation properties by getting the attenuation coefficient of the concrete/B4C. The samples of concrete/B4C were exposing to the thermal neutron radiation source (241-Americium-Berylium) at the dos rate of 29.08 mR/h. The result show that the attenuation coefficient of the sample with 20wt% B4C is 0.299cm -1 and the sample without B4C is 0.238cm -1 and hence, concrete/B4C is suitable as a shield for thermal neutron radiation.
    Matched MeSH terms: Radioactivity
  14. Jaafar Abdullah, Roslan Yahya, Lahasen@Norman Shah Dahing, Hearie Hassan, Engku Mohd Fahmi Engku Chik, Mohamad Rabaie Shari, et al.
    MyJurnal
    “Batu Bersurat Terengganu (inscribed stone)” is the oldest artifact with Jawi writing on it. The
    artifact proves that the Kingdom of Terengganu exist earlier than 1326 or 1386. To date, a lot of
    studies on the content of the inscription have been carried out by historians and archaeologists, but
    no scientific investigation about the material composition and its provenance has been performed.
    This paper focuses on the study of the origin of the Batu Bersurat Terengganu using NeutronInduced
    Prompt Gamma-Ray Techniques (NIPGAT). Portable NIPGAT system has been designed
    and developed based on volumetric measurement methods and it will be considered as a nondestructive
    testing. The system uses low activity of californium-252 (Cf-252) neutron radioactive
    sources, gamma ray spectroscopy and special computer software to carry out the investigation. The
    study found that the Batu Bersurat Terengganu is made of dolerite based on the elemental
    composition of the stone. Although most of the scientific data for the study of the origin are already
    obtained, but further research is still ongoing to complete the scope of this study.
    Matched MeSH terms: Radioactivity
  15. Nurrul Assyikeen Md. Jaffary, Wo, Yii Mei, Abdul Kadir Ishak, Noor Fadzilah Yusof, Kamarozaman Ishak, Maziah Mahmud, et al.
    MyJurnal
    On March 11, 2011, a serious accident occurred in Daiichi nuclear reactor plant, Fukushima,
    Japan which caused radioactive materials been released into the atmosphere in the form of
    aerosols and dust particles. Sea water around the plant was also found contaminated with high
    radioactivity readings. These radioactive materials could be transported by the winds and ocean
    current across international borders and cannot be controlled by human. Thus, a continuous
    monitoring activity of radionuclide content in the air and sea water needs to be conducted by the
    authorities. In addition to radioactivity monitoring, Malaysia should also control the entry of
    contaminated food in order to prevent radionuclide ingestion by human. The radionuclide 131I,
    134Cs and 137Cs were used as a measure of pollution levels and counted with gamma spectrometry
    using standard analysis method suggested by AOAC International. In this paper, details description
    of the role of Radiochemical and Environment Group, Nuclear Malaysia who’s responsible in
    analyzing the radioactivity in the food samples due to Fukushima Daiichi, Japan accident was
    included. The radioactivity limit adopted and analysis results from this monitoring were discussed
    Matched MeSH terms: Radioactivity
  16. Zalina Laili, Mohd Zaidi Ibrahim, Muhamat Omar
    MyJurnal
    A study has been carried out using a gamma-ray spectrometric system to determine the natural
    radioactivity level in bricks made from industrial waste and their associated radiation hazard.
    Brick-1 and brick-2 contained waste from coal power plant and granite industry, respectively. The
    leachability of radionuclides from these bricks was also investigated. The activity concentration
    values of 226Ra,
    228Ra,
    232Th, and 40K are 64.25, 63.15, 67.9 and 254.19 Bq/kg, respectively in brick-
    1, and 193, 164.48, 164.63 and 1348.75 Bq/kg, respectively in brick-2. The radiation hazard
    indexes such as radium equivalent activities (Raeq), representative level index (Iγr), external hazard
    index (Hex) and internal hazard index (Hin) were calculated and compared with the internationally
    approved values. Results indicate that brick-1 showed less radiological hazard than brick-2. This
    suggested that brick-1 could be used in building construction without exceeding the proposed
    criterion level.The leachability of 226Ra for bricks showed the activity concentration slightly
    exceeded 1 Bq/L which is the limit generally used for industrial wastewater.
    Matched MeSH terms: Radioactivity
  17. Muhamat Omar, Zalina Laili, Mohd Suhaimi Hamzah
    MyJurnal
    Qualitative and quantitative analysis of samples require good judgment from the analysts. These two aspects in gamma spectrometric analysis of Proficiency Test and solid radioactive waste samples for the determination of radionuclides are discussed. It is vital to judge and decide what energy peaks belong to which radionuclides prior to the creation of customized radionuclide library for the analysis of specific samples. Corrections due to radionuclide decay and growth, and the half-life assigned to a particular radionuclide in the uranium and thorium series are also discussed. Discussion on judgment to confirm the presence of thorium in food samples based on gamma spectrometry and neutron activation analysis is also provided.
    Matched MeSH terms: Radioactivity
  18. Zaini Hamzah, Ahmad Saat, Mohammed Kassim
    MyJurnal
    Many studies were carried out throughout the world on radon measurement in water especially drinking water for it can cause problem to human health. This study is an attempt to measure the level of radon present in water collect from rivers and lakes. Data gathered from this study provides important information about radiation levels in water at selected sites, because radon gas is the largest contributor to natural radioactive radiation exposure to humans. Exposure to radon gas can cause lung cancer. Liquid scintillation counting (LSC) has been applied to determine the activity concentration of radon ( 222 Rn) in water. Water samples were collected from, ex-mining lake in Perak, Sok River in Kelantan, Tembeling River in Pahang. Water samples were prepared in polyethylene bottles mixed with liquid scintillator and stored for 3 weeks to allow 222 Rn and its progeny to reach the equilibrium, and the activity concentrations ranged from 0.24-1.27 Bq/L, and 0.029 – 0.155 Bq/L for radon and radium respectively.
    Matched MeSH terms: Radioactivity
  19. Muhamat Omar, Zalina Laili, Abd Khalik Wood, Julia Abdul Karim, Zarina Masood, Mohd Fazli Zakaria, et al.
    MyJurnal
    A systematic study to assess the concentration of radionuclides in primary coolant and associated water samples from the operation of a TRIGA Mark II reactor has been carried out. The samples were transferred into appropriate counting container and were counted by efficiency-calibrated gamma spectrometer systems for several hours to obtain statistically adequate data for qualitative and quantitative evaluation of the radioactive materials presence. The primary coolant was found to contain various gamma emitting radionuclides including 24Na, 41Ar, 42K, 51Cr, , 54Mn, 56Mn, 60Co, 99mTc, 122Sb, 124Sb and 187W. Most of the detected radionuclides were inferred to be originated from activation products of (n,) nuclear reactions of elements of reactor components such as stainless steel and aluminium alloy used in the reactor system. The study confirms the integrity of the reactor system with no apparent release of any fission products radionuclide into the coolant water system.
    Matched MeSH terms: Radioactivity
  20. Masitah Alias, Zaini Hamzah, Ahmad Saat, Muhamat Omar, Zakaria Tajuddin, W. Mohamad W.A. Kadir, et al.
    MyJurnal
    The existence of Naturally Occurring Radioactive Materials (NORM) such as K-40 was studied all over the world for their characteristics and effects on human and environment. K-40 exist in the earth crust with the concentration about 1.8 mg/kg or 481 Bq/g.. In this study, the level of K-40 in soil samples were measured using gamma spectrometer equipped with hyper pure germanium detector. The samples were collected from an oil palm cultivated area of Jengka 15, in Maran District, Pahang. The results show the level of K-40 activities at various locations. The activities of K-40 are in the range 52.9-150.5 Bq/kg and total potassium concentrations are 1.60-4.50%. There are no correlation between activities of K-40 with elevation i.e. R2= 0.0885.
    Matched MeSH terms: Radioactivity
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