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Articles by M.C. Ong
Total Records ( 15 ) for M.C. Ong
  B.Y. Kamaruzzaman and M.C. Ong
  Two 20 cm sediment cores were collected with a D-section corer in the Kemaman-Chukai mangrove forest and analyzed for 210Pbex (excess 210Pb) in order to understand the sedimentation pattern. The activities of 210Pb along with the 208Po tracer were measured by Alpha Spectrometry on a silicon surface barrier detector connected to a multi channel analyzer. Sedimentation rates were determined applying 210Pb dating method and found to vary between 0.94-1.11 cm year-1. The highest accumulation rates were recorded near the river mouth and the lowest rates at the downstream. Assuming that the sedimentation rate values are accurate, this implies that the sediments in the upper 100 cm at Kemaman-Chukai mangrove forest were deposited during the past 90 years ago.
  B.Y. Kamaruzzaman , M.C. Ong , M.S. Noor Azhar , S. Shahbudin and K.C.A. Jalal
  Surface sediments collected from seven estuarine mangrove forests of Terengganu region (100 sampling points) were anaylzed for Pb, Cu and Zn using the sensitive Inductively Coupled Plasma Mass Spectrometer (ICP-MS). The average concentration of Pb, Cu and Zn were 10.5±7.12 mg g-1 dry weights, 31.1± 16.5 mg g-1 dry weights and 20.8±13.3 mg g-1 dry weights, respectively. The statistical analysis of Pearson correlation matrix has proved that there is a significant relationship between the metal concentration and the grain size. The concentration of Pb, Cu and Zn decreased with the decrease of mean size particle, suggesting their association with the fine fraction of the sediments. In this study, Enrichment Factors (EF) were calculated to assess whether the concentrations observed represent background or contaminated levels. The analysis suggests that all studied elements were considered to be dominantly terrigenous in origin. Data obtained also provides a scientific discovery and data for a better understanding and proper management of the mangrove forests of Terengganu.
  M.C. Ong and Kamaruzzaman, B. Y.

Problem statement:The accumulation of metal contaminants in sediments can pose serious environmental problems to the surrounding areas. Trace metal contamination in sediment could affect the water quality and the bio-assimilation and bioaccumulation of metals in aquatic organisms, resulting in potential long-term implications on human health and ecosystem.
Approach: About 154 bottom sediment samples were collected using Smith McIntyre in a transect pattern from South China Sea East Coast coastal water (Terengganu, Pahang and Johor coastal area). The study focused on the levels of Pb and Cu in order to assess the extent of environment pollution and to discuss the origin of these contaminants in the sediment.
Results: Results showed that the average concentration of Pb and Cu was 33.70 µg g-1 dry weights and 22.40 µg g-1 dry weights, respectively. Pb and Cu have relatively lower Enrichment Factors (EF) value and geo-accumulation (Igeo) indices in study area and these analysis validated that elevated heavy metals concentration in most sample are not due to artificial contamination.
Conclusion: Overall, geochemistry of the samples showed the effect of both natural and anthropogenic inputs to the catchment, however, natural processes were more dominant than anthropogenic inputs in concentrating metals. Results obtained would help to develop strategies for pollution control and sediment remediation of coastal waters in the South China Sea.

  S. Hasrizal , B.Y. Kamaruzzaman , I. Sakri , M.C. Ong and M.S. Noor Azhar
  Problem statement: The distribution of organic carbon in the surface sediment is a crucial indicator for current productivity in the ocean especially in the nearshore area. The difference of organic carbon in the surface sediment reflects the influence of current movement on the bottom sediment. Approach: This study was carried out to oversee the difference of organic carbon distribution during pre and post-monsoon seasons. For the purpose of the study, 42 surface sediments in the Terengganu near shore area were collected and determined for organic carbon by using the wet dichromate acid method. Results: The concentration of organic carbon was significantly different between the seasons showing a relatively higher content during pre-monsoon seasons. In this study, the average concentration of organic carbon in pre-monsoon was 1.14±0.29% and varied from 0.60-1.80%. Meanwhile during post-monsoon seasons, the average concentration of organic carbon was slightly lower to 0.82±0.23% and ranged from 0.24-1.32%. Conclusion: Generally, the average concentration of organic carbon in South China Sea was low compared to the occurrence in riverine environment as well as the mangrove environment.
  B.Y. Kamaruzzaman , A. Siti Waznah , M.C. Ong , S. Shahbudin and K.C.A. Jalal
  The percentage organic carbon content of 62 bottom estuarine sediment in Pahang river estuary were analyzed using the wet dichromate oxidation method. In this study, the organic carbon distribution ranged from 0.09 to 2.05%. The high concentration can be found near the Pahang river mouth while the low concentration occurred at upstream. The sediment particle size at the same transects were also measured with the dry sieving and laser diffraction method. The average concentration of organic carbon was 0.88% while the average grain size was 2.44 φ. In this study, the carbon organic showed a significant relationship with the mean size (p<0.05) with the organic carbon content increase with the increase of mean size values.
  B.Y. Kamaruzzaman , A. Siti Waznah , M.S. Mohd Zahir , M.C. Ong , S. Shahbudin , K.C.A. Jalal , Z. Rina Sharlinda , A.T. Shuhada , B. Akbar John , B. Joseph , S.M. Al-Barwani and J.S. Goddard
  Bottom sediments from 62 stations at Pahang river-estuary were analyzed for the concentrations of Chromium (Cr), Manganese (Mn) and Cobalt (Co). Heavy metal concentrations were analyzed by using an Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The average dry weight concentrations of Cr, Mn and Co were 62.80±20.04, 416.21±127.41 and 7.93±3.25 μg g-1, respectively. The observed concentrations of the studied metals were significantly higher near the estuary and declining as the sampling points were further away from the estuary. The Enrichment Factors (EFs) were calculated and all elements showed metal contamination was predominantly of terrigenous in origin.
  M.C. Ong , D. Menier , N.A.M. Shazili and V. Dupont
  Concentration of selected Metallic Trace Elements (MTEs), chromium, manganese, iron, cobalt, copper, zinc, lead and cadmium in surficial sediments from gulf of Morbihan were studied in order to understand the current MTEs contamination due to urbanization and mariculture economic development surrounding the gulf region. Therefore, the distribution, enrichment and accumulation of MTEs in 101 surficial sediments collected by Orange Peel grab were characterized for MTEs content using ICP-MS after mixed acid digestion. The average concentrations of selected MTEs were 36.2±23.9 μg g-1 dry weight (Cr), 278±140 μg g-1 dry weight (Mn), 2.40±1.29% (Fe), 14.4±5.31 μg g-1 dry weight (Co), 16.4±10.3 μg g-1 dry weight (Cu), 38.1±19.1 μg g-1 dry weight (Zn), 34.6±13.9 μg g-1 dry weight (Pb) and 0.11±0.06 μg g-1 dry weight (Cd), respectively. Results from the analysis showed that MTEs studied have relatively low index of geo-accumulation and enrichment factors values and were in value to conclude practically uncontaminated within the gulf. Overall, the geochemistry of the sediment of gulf of Morbihan was influenced by both natural and anthropogenic inputs to the catchment. However, direct comparison with upper continental crust indicated that natural processes were more dominant than anthropogenic input in concentrating metals.
  B.Y. Kamaruzzaman , M.C. Ong and K.C.A. Jalal
  Heavy metal (Cu, Zn and Pb) concentrations in the muscle, gill and stomach of fish species from Mengabang Telipot River, Terengganu were measured with a fast and sensitive Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The relationships between fish size (length and weight) and metal concentrations in the tissues were also investigated. The average concentration of Cu, Zn and Pb was 13.39, 19.88 and 0.30 mg kg-1 dry wt., respectively. A marked relationship between metal contents of the studied species was observed. Generally, the mean concentrations of all the elements were relatively high in stomach, followed by gills and lowest in muscle. The positive relationship of these elements with fish length and weight were observed, suggesting the accumulation of these elements were occurred in the fish. Overall, metal levels found were lower than the international standards of reference and the examined fish were not associated with enhanced metal content in their tissues and were safe within the limits for human consumption.
  B.Y. Kamaruzzaman , M.C. Ong , S.Z. Rina and B. Joseph
  In this study, the concentration of Pb, Cu and Zn were determined in muscle, gills and stomach of six fish species caught from Pahang river estuary. These metals concentration were measured by ICP-MS in order to assess the fish contamination with these metals. This study showed that all catfishes (Arius sp.) presented the highest metals content. Tissue analysis revealed that the stomach accumulated the highest level of these metals. Based on the results, metal concentration in the edible part of the examined fish (muscle) were in the safety permissible levels for human consumption.
  K. Zaleha , B.Y. Kamaruzzaman , B. Akbar John and M.C. Ong
  Balok, Pekan and Penor have been observed to be nesting grounds of the horseshoe crab. Present study was conducted to assess the metal concentration in sediment of horseshoe crab the nesting ground along the east coast of peninsular Malaysia. Acid Digestion was performed using (HF, HNO3, HCl, EDTA and H3BO4) before determining the actual concentration of heavy metals using ICPMS. 2-way ANOVA was used to determine the significance of the results. In all stations, Pb was in highest concentration (40.36 μg g-1) followed by Cu (13.44 μg g-1) and the least concentrated metal in the nesting ground was Cd with the high concentration of (0.26 μg g-1). EF values showed that Pb is of anthropogenic source and Cd is of minimum enrichment. Although the levels of Pb are low and regarded harmless to the horseshoe crab, the fear of it affecting those who consume the eggs as well as the crab is still in consideration.
  M.C. Ong , N.A.M. Shazili , D. Menier and A.W.M. Effendy
  The concentration of trace elements, copper, zinc, cadmium and lead in the two oyster species (Ostrea edulis) and (Crassostrea gigas) collected from mariculture sites in the Quiberon bay were studied to investigate metal contamination in the surrounding area and its significant risk assessment to human who consumed the both species. Cu, Zn, Cd and Pb were analyzed by using inductively coupled plasma-mass spectrometry after acid digestion process. Certified reference materials, Oyster tissue, SRM1556a was used to validate the methods and the results shown a good agreement with the certified values. The levels of Cu, Zn, Cd and Pb in oyster flesh were 0.26-14.5, 4.61-83.9, 0.01-0.11 and 0.02-0.41 mg kg-1 wet weight. Element levels in C. gigas were generally higher than O. edulis. Element concentrations in the flesh were assessed for human consumption according to Provisional Tolerable Weekly Intake (PTWI) and Provisional Tolerable Daily Intake (PTDI). Due to their bioaccumulation capacity of trace elements, both oysters’ species had the potential of being used as biomonitors to control the aquatic contaminations by trace elements.
  B.Y. Kamaruzzaman , M.C. Ong and A.H. Khali
  Muscle, stomach and gill from four dominant fish species, Mytus nemurus, Pristolepis fasciata, Ompok bimaculatus and Osteochilus hasseltii, caught from Bebar peat swamp forest river were analyzed for mercury (Hg). The concentration of Hg was measured with a fast and sensitive Flow Injector Mercury Spectrometer (FIMS). The average Hg concentration of all species caught was 0.169 μg g-1 dry weights, lower than a limit for human consumption recommended by the World Health Organization, 0.5 μg g-1 dry weights. The mean concentration of Hg was relatively high in stomach (0.28x0.12 μg g-1 dry weights) followed by gill (0.17x0.06 μg g-1 dry weights) and lowest in muscle (0.05x0.02 μg g-1 dry weights). The positive relationship of Hg with fish length and weight suggesting that the accumulation of Hg were formed in the fish.
  B.Y. Kamaruzzaman , M.C. Ong , K. Zaleha and S. Shahbudin
  Muscle and feather in tissue of 40 juveniles and 40 adult green-lipped mussel Perna veridis (L.) collected from Muar Estuary, Johor were analyzed for copper (Cu), cadmium (Cd), lead (Pb) and zinc (Zn) concentration using a fast and sensitive Inductively Coupled Plasma Mass Spectrometer (ICP-MS). In this study, the average concentration of Cu was 8.96 μg g-1 dry weights, Cd with 0.58 μg g-1 dry weight, Pb averaging 2.28 μg g-1 dry weights and Zn averaged to 86.73 μg g-1 dry weight. The highest accumulation of metal studied was found in feather sample compared to the muscle. The positive relationship of Cu, Cd, Pb and Zn with P. virdis length suggesting that the accumulation of these metals were formed in the mussel. In all cases, metal levels found were lower than the guideline of international standards of reference and the examined bivalve were not associated with enhanced metal content in their tissues and were safe within the limits for human consumption.
  B.Y. Kamaruzzaman , N.T. Shuhada , B. Akbar , S. Shahbudin , K.C.A. Jalal , M.C. Ong , S.M. Al-Barwani and J.S. Goddard
  Surface sediment samples were collected from 5 different zones of the Langkawi coastal waters, Malaysia to determine the concentration of Lead (Pb) and Copper (Cu) by using the sensitive Inductively Coupled Plasma Mass Spectrometer (ICP-MS). The concentration of heavy metals was compared with the world average concentration of shale values. It was found that the total concentration of Pb was between 12.25 and 71.38 μg g-1 dw with mean concentration value of 41.87±7.30 μg g-1 dw which was two fold higher than the average shale value (20 μg g-1). Statistical analysis showed that the significant variation in Pb concentration between different sampling stations (p<0.05). Copper (Cu) concentration was ranged between 0.40 and 30.95 μg g-1 dw with mean concentration of 11.19±5.2 μg g-1 dw which was lower than the average shale value (45 μg g-1 dw). Enrichment Factor (EF) showed that source of Pb concentration in the study area was partially due to anthropogenic activities and the source of Cu was dominantly from terrigenous in origin. Results of the analysis showed that a coastal area of Langkawi is facing moderate metal pollution with increased rate of deposition.
  B.Y. Kamaruzzaman , K.Y.S. Willison and M.C. Ong
  The vertical profiles of 230Thexcess and 230Thexcess/232Th in a sediment core have been used to determine the sedimentation rates of Terengganu River estuary, Malaysia. Applying the 230Thexcess and 230Thexcess/232Th method, U and Th isotopic involved complete dissolution of the samples, followed by separation on anion exchange, average sedimentation rates of 1.02 and 1.01 cm year-1 were obtained, respectively. The results of the accretion rate obtained from the both methods are consistent with average sedimentation rates of 1.01 cm year-1. Assuming that the accretion rate values are accurate, this may imply that the sediments at the deepest core at 14 cm were deposited during the last 14.2 years ago.
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