Displaying publications 1 - 20 of 114 in total

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  1. Abbas SZ, Rafatullah M, Khan MA, Siddiqui MR
    Front Microbiol, 2018;9:3348.
    PMID: 30692985 DOI: 10.3389/fmicb.2018.03348
    The industrial contamination of marine sediments with mercury, silver, and zinc in Penang, Malaysia was studied with bio-remediation coupled with power generation using membrane less open (aerated) and closed (non-aerated) sediment microbial fuel cells (SMFCs). The prototype for this SMFC is very similar to a natural aquatic environment because it is not stimulated externally and an oxygen sparger is inserted in the cathode chamber to create the aerobic environment in the open SMFC and no oxygen supplied in the closed SMFC. The open and closed SMFCs were showed the maximum voltage generation 300.5 mV (77.75 mW/m2) and 202.7 mV (45.04 (mW/m2), respectively. The cyclic voltammetry showed the oxidation peak in open SMFCs at +1.9 μA and reduction peak at -0.3 μA but in closed SMFCs oxidation and reduction peaks were noted at +1.5 μA and -1.0 μA, respectively. The overall impedance (anode, cathode and solution) of closed SMFCs was higher than open SMFCs. The charge transfer impedance showed that the rates of substrate oxidation and reduction were very low in the closed SMFCs than open SMFCs. The Nyquist arc indicated that O2 act as electron acceptor in the open SMFCs and CO2 in the closed SMFCs. The highest remediation efficiency of toxic metals [Hg (II) ions, Zn (II) ions, and Ag (I) ions] in the open SMFCs were 95.03%, 86.69%, and 83.65% in closed SMFCs were 69.53%, 66.57%, and 65.33%, respectively, observed during 60-80 days. The scanning electron microscope and 16S rRNA analysis showed diverse exoelectrogenic community in the open SMFCs and closed SMFCs. The results demonstrated that open SMFCs could be employed for the power generation and bioremediation of pollutants.
    Matched MeSH terms: Mercury
  2. Abdi MM, Abdullah LC, Sadrolhosseini AR, Mat Yunus WM, Moksin MM, Tahir PM
    PLoS One, 2011;6(9):e24578.
    PMID: 21931763 DOI: 10.1371/journal.pone.0024578
    A new sensing area for a sensor based on surface plasmon resonance (SPR) was fabricated to detect trace amounts of mercury and lead ions. The gold surface used for SPR measurements were modified with polypyrrole-chitosan (PPy-CHI) conducting polymer composite. The polymer layer was deposited on the gold surface by electrodeposition. This optical sensor was used for monitoring toxic metal ions with and without sensitivity enhancement by chitosan in water samples. The higher amounts of resonance angle unit (ΔRU) were obtained for PPy-CHI film due to a specific binding of chitosan with Pb(2+) and Hg(2+) ions. The Pb(2+) ion bind to the polymer films most strongly, and the sensor was more sensitive to Pb(2+) compared to Hg(2+). The concentrations of ions in the parts per million range produced the changes in the SPR angle minimum in the region of 0.03 to 0.07. Data analysis was done by Matlab software using Fresnel formula for multilayer system.
    Matched MeSH terms: Mercury/chemistry
  3. Abo-Shakeer, L.K.A., Rahman, M.F.A., Yakasai, H., Syed, M.A., Shukor M.Y., Bakar, N.A., et al.
    MyJurnal
    Bacterial based remediation of environmental toxicants is a promising innovative technology
    for molybdenum pollution. To date, the enzyme responsible for molybdate reduction to Moblue
    from bacteria show that the Michaelis-Menten constants varies by one order of magnitude.
    It is important that the constants from newer enzyme sources be characterized so that a
    comparison can be made. The aim of this study is to characterize kinetically the enzyme from a
    previously isolated Mo-reducing bacterium; Bacillus pumilus strain Lbna. The maximum
    activity of this enzyme occurred at pH 5.5 and in between 25 and 35 oC. The Km and Vmax of
    NADH were 6.646 mM and 0.057 unit/mg enzyme, while the Km and Vmax of LPPM were 3.399
    mM and 0.106 unit/mg enzyme. The results showed that the enzyme activity for Bacillus
    pumilus strain Lbna were inhibited by all heavy metals used. Zinc, copper, silver, chromium,
    cadmium and mercury all caused more than 50% inhibition to the Mo-reducing enzyme activity
    with copper being the most potent with an almost complete inhibition of enzyme activity
    observed.
    Matched MeSH terms: Mercury
  4. Abu Bakar N, Mohd Sata NS, Ramlan NF, Wan Ibrahim WN, Zulkifli SZ, Che Abdullah CA, et al.
    Neurotoxicol Teratol, 2017 Jan-Feb;59:53-61.
    PMID: 27919701 DOI: 10.1016/j.ntt.2016.11.008
    Chronic exposure to mercury (Hg) can lead to cumulative impairments in motor and cognitive functions including alteration in anxiety responses. Although several risk factors have been identified in recent year, little is known about the environmental factors that either due exposure toward low level of inorganic mercury that may led to the developmental disorders. The present study investigated the effects of embryonic exposure of mercury chloride on motor function and anxiety-like behavior. The embryo exposed to 6 different concentrations of HgCl2 (7.5, 15, 30, 100, 125, 250nM) at 5hpf until hatching (72hpf) in a semi-static condition. The mortality rate increased in a dose dependent manner where the chronic embryonic exposure to 100nM decreased the number of tail coiling, heartbeat, and swimming activity. Aversive stimulus was used to examine the effects of 100nM interferes with the development of anxiety-related behavior. No elevation in both thigmotaxis and avoidance response of 6dpf larvae exposed with 100nM were found. Biochemical analysis showed HgCl2 exposure affects proteins, lipids, carbohydrates and nucleic acids of the zebrafish larvae. These results showed that implication of HgCl2 on locomotor and biochemical defects affects motor performance and anxiety-like responses. Yet, the potential underlying mechanisms these responses need to be further investigated which is crucial to prevent potential hazards on the developing organism due to neurotoxicant exposure.
    Matched MeSH terms: Mercury/toxicity*
  5. Abu Ismaiel A, Aroua MK, Yusoff R
    Sensors (Basel), 2014 Jul 21;14(7):13102-13.
    PMID: 25051034 DOI: 10.3390/s140713102
    In this study, a potentiometric sensor composed of palm shell activated carbon modified with trioctylmethylammonium thiosalicylate (TOMATS) was used for the potentiometric determination of mercury ions in water samples. The proposed potentiometric sensor has good operating characteristics towards Hg (II), including a relatively high selectivity; a Nernstian response to Hg (II) ions in a concentration range of 1.0 × 10(-9) to 1.0 × 10(-2) M, with a detection limit of 1 × 10(-10) M and a slope of 44.08 ± 1.0 mV/decade; and a fast response time (~5 s). No significant changes in electrode potential were observed when the pH was varied over the range of 3-9. Additionally, the proposed electrode was characterized by good selectivity towards Hg (II) and no significant interferences from other cationic or anionic species.
    Matched MeSH terms: Mercury/chemistry*
  6. Ahmad A, Ghufran R, Al-Hosni TK
    J Environ Health Sci Eng, 2019 Dec;17(2):1195-1203.
    PMID: 32030185 DOI: 10.1007/s40201-019-00434-2
    To investigate the interaction of zinc oxide nanoparticles (ZnO NPs) with fly ash soil (FAS) for the reduction of metals from FAS by Parthenium hysterophorus were studied. The average accumulation of metals by P. hysterophorus stem were Fe 79.6%; Zn 88.5%; Cu 67.5%; Pb 93.6%; Ni 43.5% and Hg 39.4% at 5.5 g ZnO NP. The concentration of ZnO NP at 1.5 g did not affect the metals accumulation, however at 5.5 g ZnO NP showed highest metal reduction was 96.7% and at 10.5-15.5 g ZnO NP of 19.8%. The metal reduction rate was R
    max
    for Fe 16.4; Zn 21.1; Pb 41.9; Hg 19.1 was higher than Ni 6.4 and Cu 11.3 from the FAS at 5.5 g ZnO NP whereas, the reduction rate of Pb showed highest. With doses of 5.5 g ZnO NP the biomass increased upto 78%; the metal reduced upto 98.7% with the share of 100% ZnO NP from FAS. Further investigation with phytotoxicity the plant reactive oxygen species (ROS) production were affected due was mainly due to the recovery of metals from FAS (R2 = 0.99).
    Matched MeSH terms: Mercury
  7. Ahmad M, Hamzah H, Sufliza Marsom E
    Talanta, 1998 Oct;47(2):275-83.
    PMID: 18967326
    An optical sensor for Hg(II) monitoring using a complex of zinc dithizonate immobilised on XAD 7 which is based on reflectance spectrophotometry has been developed in this study. Measurements were made using a kinetic approach whereby the reflectance signal is measured at a fixed time of 5 min. The sensor could be regenerated using a saturated solution of KCl in 1 M sulphuric acid. The sensor was found to have an optimum response at pH 3.0 with respective measurement repeatability and probe-to-probe reproducibility of 1.53% and 5.26%. A linear response was observed in the Hg(II) concentration range of 0.0-180.0 ppm with a calculated limit of detection (LOD) of 0.05 ppm. The results obtained for aqueous Hg(II) determination using this probe were found to be comparable with the well-established method of atomic absorption spectrometry.
    Matched MeSH terms: Mercury
  8. Ahmad NI, Noh MF, Mahiyuddin WR, Jaafar H, Ishak I, Azmi WN, et al.
    Environ Sci Pollut Res Int, 2015 Sep;22(17):12960-74.
    PMID: 25916470 DOI: 10.1007/s11356-015-4415-9
    This study is to determine total mercury in edible tissues of eight species of cephalopods and 12 species of crustaceans purchased from 11 identified major fish landing ports and wet markets throughout Peninsular Malaysia. The concentration of mercury was measured by cold vapor atomic absorption spectrometry (AAS) technique using the Perkin Elmer Flow Injection Mercury System (FIMS-400). In general, the mercury levels were low with concentrations in cephalopods ranging from 0.099 to 2.715 mg/kg dry weight (or 0.0184-0.505 mg/kg wet weight) and in crustaceans ranging from 0.057 to 1.359 mg/kg dry weight (or 0.0111-0.265 mg/kg wet weight). The mercury levels showed no significant differences (P > 0.05) between species for both cephalopods and crustaceans. There was no significant correlation between mercury concentrations and the body size of individual for both groups as well. Comparisons with mercury levels obtained found from other previous studies and/or species noted that they were of the same magnitude or relatively low compared to various locations reported worldwide.
    Matched MeSH terms: Mercury/analysis*; Mercury/chemistry
  9. Ahmad NI, Noh MF, Mahiyuddin WR, Jaafar H, Ishak I, Azmi WN, et al.
    Environ Sci Pollut Res Int, 2015 Mar;22(5):3672-86.
    PMID: 25256581 DOI: 10.1007/s11356-014-3538-8
    This study was conducted to determine the concentration of total mercury in the edible portion of 46 species of marine fish (n = 297) collected from selected major fish landing ports and wholesale markets throughout Peninsular Malaysia. Samples were collected in June to December 2009. Prior to analysis, the fish samples were processed which consisted of drying at 65 °C until a constant weight was attained; then, it was grounded and digested by a microwave digestion system. The analytical determination was carried out by using a mercury analysis system. Total mercury concentration among fish species was examined. The results showed that mercury concentrations were found significantly higher (p 20 cm) and were positively related with fish size (length and weight) in all fish samples. Despite the results, the level of mercury in marine fish did not exceed the permitted levels of Malaysian and JECFA guideline values at 0.5 mg/kg methylmercury in fish.
    Matched MeSH terms: Mercury/analysis*; Methylmercury Compounds/analysis*
  10. Ainul Haezah Noruzman, Mohammad Ismail, Taliat Ola Yusuf, Parham Forouzani
    MyJurnal
    The volume of waste generated from surface coating industries is of global concern. The disposal of this waste in the form of effluent has put enormous pressure on land and also poses as a health hazard when it leaches into soil and underground water. The study aims to examine the utilization of vinyl acetate effluents from water based paint factories as an admixture in concrete. Concrete specimens containing 0%, 2.5%, 5% and 10% of vinyl acetate effluents by weight of cement were prepared. The specimens were tested for drying shrinkage for 28 days and porosity was tested using mercury intrusion porosimetry. Findings show that concrete containing various proportions of vinyl acetate effluents manifests higher shrinkage behaviour compared to the control item. An investigation of pore size distribution reveals that polymer effluents have particles size larger than 50 nm which are categorize as macroporous in accordance to IUPAC classification. It can be concluded that adding polymer vinyl acetate effluents affects concrete deformation due to the condition of its pore structures. The utilization of this material may provide beneficial effect in terms of the durability performance of concrete and minimize environmental pollution.
    Matched MeSH terms: Mercury
  11. AlOmar MK, Alsaadi MA, Hayyan M, Akib S, Ibrahim M, Hashim MA
    Chemosphere, 2017 Jan;167:44-52.
    PMID: 27710842 DOI: 10.1016/j.chemosphere.2016.09.133
    Recently, deep eutectic solvents (DESs) have shown their new and interesting ability for chemistry through their involvement in variety of applications. This study introduces carbon nanotubes (CNTs) functionalized with DES as a novel adsorbent for Hg(2+) from water. Allyl triphenyl phosphonium bromide (ATPB) was combined with glycerol as the hydrogen bond donor (HBD) to form DES, which can act as a novel CNTs functionalization agent. The novel adsorbent was characterized using Raman, FTIR, XRD, FESEM, EDX, BET surface area, TGA, TEM and Zeta potential. Response surface methodology was used to optimize the removal conditions for Hg(2+). The optimum removal conditions were found to be pH 5.5, contact time 28 min, and an adsorbent dosage of 5 mg. Freundlich isotherm model described the adsorption isotherm of the novel adsorbent, and the maximum adsorption capacity obtained from the experimental data was 186.97 mg g(-1). Pseudo-second order kinetics describes the adsorption rate order.
    Matched MeSH terms: Mercury/chemistry*
  12. Alina, M., Azrina, A., Mohd Yunus, A.S., Mohd Zakiuddin, S., Mohd Izuan Effendi, H., Muhammad Rizal, R.
    MyJurnal
    Level of heavy metals in marine ecosystem has been intensively studied during recent years as these hazardous substances could be accumulated in the biota. Generally, the presence of contaminants in fish is a result of human activities such as industrial and agricultural wastes. In this study, the marine fish and shellfish from the Straits of Malacca were analyzed using Inductively Coupled Plasma Optical Emission Spectrophotometer (ICP-OES) and Flow Injection Mercury System (FIMS) for Cd, As and Pb and Hg, respectively. The Straits of Malacca is one of the busiest shipping routes in the world that make the level of heavy metals potentially high besides the various industrial activities along the west region of Peninsular Malaysia. The range of heavy metals in samples were 1.0-3-6.5-3 µg/ g wet sample for Hg, 0.5-2-47-2 µg/ g wet sample for Cd, 0.01-0.39 µg/ g wet sample for Pb and 0.14-6.57 µg/ g wet sample for As. Most part of the values was below the permitted limit set by FAO/WHO 2004 as well as Food Act 1983 and Food Regulations 1985. Therefore it can be generalized that fish and shellfish from the Straits of Malacca are safe to consume in terms of these heavy metals concentrationand do not constitute a risk for human health.
    Matched MeSH terms: Mercury
  13. Alkarkhi AF, Ismail N, Ahmed A, Easa Am
    Environ Monit Assess, 2009 Jun;153(1-4):179-85.
    PMID: 18504644 DOI: 10.1007/s10661-008-0347-x
    Statistical analysis of heavy metal concentrations in sediment was studied to understand the interrelationship between different parameters and also to identify probable source component in order to explain the pollution status of selected estuaries. Concentrations of heavy metals (Cu, Zn, Cd, Fe, Pb, Cr, Hg and Mn) were analyzed in sediments from Juru and Jejawi Estuaries in Malaysia with ten sampling points of each estuary. The results of multivariate statistical techniques showed that the two regions have different characteristics in terms of heavy metals selected and indicates that each region receives pollution from different sources. The results also showed that Fe, Mn, Cd, Hg, and Cu are responsible for large spatial variations explaining 51.15% of the total variance, whilst Zn and Pb explain only 18.93 of the total variance. This study illustrates the usefulness of multivariate statistical techniques for evaluation and interpretation of large complex data sets to get better information about the heavy metal concentrations and design of monitoring network.
    Matched MeSH terms: Mercury/analysis
  14. Amir Sultan MM, Goh CT, Wan Puteh SE, Mokhtar M
    Int J Health Care Qual Assur, 2019 Feb 11;32(1):34-44.
    PMID: 30859864 DOI: 10.1108/IJHCQA-08-2017-0161
    PURPOSE: Mercury is widely used in medical and healthcare facilities as dental amalgam, mercury-added medical devices, thiomersal-containing vaccines, laboratory analysis and for other general applications despite the hazards. Various agencies consistently promote mercury-free medical facilities through mercury-free alternatives and better management practices, which are in line with the Minamata Convention on Mercury that aims to protect human health and environment from anthropogenic mercury release. The paper aims to discuss these issues.

    DESIGN/METHODOLOGY/APPROACH: The authors conducted a gap analysis on recommended practices gathered from the literature and current practices gathered through semi-structured interviews with Malaysian medical personnel. A life cycle approach was adopted covering mercury use: input, storage, handling, accident, waste disposal and governance phases.

    FINDINGS: The authors found that there are significant gaps between recommended and current mercury management practices. Analysis indicates improper mercury management as the main contributor to these gaps. The authors found from recommended practices that core components needing improvement include: mercury management action plan, mercury use identification team, purchasing policy, proper guidelines and monitoring systems.

    PRACTICAL IMPLICATIONS: This study helps us to understand mercury management practices and suggests essential steps to establish a mercury-free medical facility.

    ORIGINALITY/VALUE: This study explored the gaps between recommended and current mercury management practices in a medical facility and contributes to the Minamata Convention on Mercury aspirations.

    Matched MeSH terms: Mercury/adverse effects*
  15. Ang HH, Lee KL
    Food Chem Toxicol, 2006 Aug;44(8):1245-50.
    PMID: 16567029 DOI: 10.1016/j.fct.2006.01.014
    The DCA (Drug Control Authority), Malaysia has implemented the phase three registration of traditional medicines on 1 January 1992. As such, a total of 100 products in various pharmaceutical dosage forms of a herbal preparation found in Malaysia, containing tongkat Ali hitam, either single or combined preparations, were analyzed for the presence of a heavy toxic metal, mercury, using atomic absorption spectrophotometer, after performing a simple random sampling to enable each sample an equal chance of being selected in an unbiased manner. Results showed that 26% of these products possessed 0.53-2.35 ppm of mercury, and therefore, do not comply with the quality requirement for traditional medicines in Malaysia. The quality requirement for traditional medicines in Malaysia is not exceeding 0.5 ppm for mercury. Out of these 26 products, four products have already registered with the DCA, Malaysia whilst the rest, however, have not registered with the DCA, Malaysia.
    Matched MeSH terms: Mercury/analysis*
  16. Ang HH, Lee KL
    Int J Toxicol, 2007 Sep-Oct;26(5):433-9.
    PMID: 17963130 DOI: 10.1080/10915810701583036
    The DCA (Drug Control Authority) of Malaysia implemented phase 3 registration of traditional medicines in January 1992 with special emphasis on the quality, efficacy, and safety of all dosage forms of these medicines. For this reason, a total of 100 herbal products containing Smilax myosotiflora were purchased in the Malaysian market and analyzed for mercury content, as mercury is a recognized reproductive toxicant. The products were analyzed using cold vapor atomic absorption spectrophotometry. It was found that 89% of the above products do not exceed 0.5 ppm of mercury. Heavy metal poisoning such as mercury has been associated with traditional medicines. Therefore, it is important that doctors and health care practitioners are aware of these risks and finding ways to minimize them, including questions pertaining to the use of these remedies during the routine taking of a patient's history.
    Matched MeSH terms: Mercury/analysis*
  17. Ang HH, Lee EL, Cheang HS
    Int J Toxicol, 2004 Jan-Feb;23(1):65-71.
    PMID: 15162849 DOI: 10.1080/10915810490269654
    The DCA (Drug Control Authority), Malaysia, has implemented the phase 3 registration of traditional medicines on 1 January 1992, with special emphasis on the quality, efficacy, and safety (including the presence of heavy metals) in all pharmaceutical dosage forms of traditional medicine preparations. As such, a total of 100 products in various pharmaceutical dosage forms of a herbal preparation, containing Tongkat Ali, were analyzed for mercury content using cold vapor atomic absorption spectrophotometer. Results showed that 36% of the above products possessed 0.52 to 5.30 ppm of mercury and, therefore, do not comply with the quality requirement for traditional medicines in Malaysia. Out of these 36 products, 5 products that possessed 1.05 to 4.41 ppm of mercury were in fact have already registered with the DCA, Malaysia. However, the rest of the products that contain 0.52 to 5.30 ppm of mercury still have not registered with the DCA, Malaysia. Although this study showed that only 64% of the products complied with the quality requirement for traditional medicines in Malaysia pertaining to mercury, they cannot be assumed safe from mercury contamination because of batch-to-batch inconsistency.
    Matched MeSH terms: Mercury/analysis*
  18. Anuar K, Hamdan S
    Talanta, 1992 Dec;39(12):1653-6.
    PMID: 18965586
    A new lead(II) electrode has been constructed with poly(hydroxamic acid) (PHXA) as the active material and silicone rubber as the supporting material. The electrode gave near Nerstian response over the concentration range 4 x 10(-5)-1 x 10(-2)M lead(II). The detection limit of the electrode is approximately 4 x 10(-6)M and the electrode works well in the pH range 4.5-6.0. The response time was 50-120 sec over the whole concentration range and the electrode has a working life of at least 4 weeks. Iron(III) severely poisoned the electrode membrane. Nickel(II) and mercury(II) gave very strong interference compared to copper(II), silver(I), cobalt(II), sodium(I), potassium(I), zinc(II) and cadmium(II) which gave some or little interference. Values determined with atomic absorption (AAS) and a commercial lead(II) electrode were in good agreement with those measured with the lead(II) electrode reported here.
    Matched MeSH terms: Mercury
  19. Assi MA, Hezmee MN, Haron AW, Sabri MY, Rajion MA
    Vet World, 2016 Jun;9(6):660-71.
    PMID: 27397992 DOI: 10.14202/vetworld.2016.660-671
    Lead, a chemical element in the carbon group with symbol Pb (from Latin: Plumbum, meaning "the liquid silver") and has an atomic number 82 in the periodic table. It was the first element that was characterized by its kind of toxicity. In animal systems, lead (Pb) has been incriminated in a wide spectrum of toxic effects and it is considered one of the persistent ubiquitous heavy metals. Being exposed to this metal could lead to the change of testicular functions in human beings as well as in the wildlife. The lead poising is a real threat to the public health, especially in the developing countries. Accordingly, great efforts on the part of the occupational and public health have been taken to curb the dangers of this metal. Hematopoietic, renal, reproductive, and central nervous system are among the parts of the human body and systems that are vulnerable toward the dangers following exposure to high level of Pb. In this review, we discussed the massive harmful impact that leads acetate toxicity has on the animals and the worrying fact that this harmful toxicant can be found quite easily in the environment and abundance. Highlighting its (Pb) effects on various organs in the biological systems, its economic, as well as scientific importance, with the view to educate the public/professionals who work in this area. In this study, we focus on the current studies and research related to lead toxicity in animals and also to a certain extent toward human as well.
    Matched MeSH terms: Mercury
  20. Babji AS, Embong MS, Woon WW
    Bull Environ Contam Toxicol, 1979 Dec;23(6):830-6.
    PMID: 519067
    Matched MeSH terms: Mercury/analysis
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