31 research outputs found

    Metals fractionation and evaluation of their risk connected with urban and industrial influx in the Klang River surface sediments, Malaysia.

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    In the present study, concentration, distribution and speciation of trace metals were conducted to assess the overall classification of Ni, Cu and Pb as well as their risk status in the surface sediments of Klang River. Sequential extraction technique (SET) was used to evaluate the four (exchangeable, acid-reducible, oxidisable-organic and residual) fractions of the surface sediments. The total concentrations of metals ranged from 5.26 g/g d.w. to 22.93 g/g d.w for Ni; 9.47-66.74 g/g d.w. for Cu; and 24.78-62.35 g/g d.w. for Pb. The fractionation of studied metals (except Cu) in most stations were in the order of residual > acid-reducible > oxidisable-organic > exchangeable. The degree of surface sediments contamination was computed for Risk Assessment Code (RAC), Individual Contamination Factors (ICF) and Global contamination factor (GCF). The result of this study showed that none of the metals studied had potential risk to fauna and flora of the Klang River systems

    Assessment of metals contamination in Klang River surface sediments by using different indexes.

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    Surface sediments (0-5 cm) from 21 stations throughout Klang River were sampled for metal concentration as well sediment's pH, total organic carbon (TOC) and particles sizes to obtain an overall classification of metal contaminations in the area. The concentration of metals (μg/g, Fe%, dw) were as follows: 0.57- 2.19 Cd; 31.89-272.33 Zn; 5.96-24.47 Ni; 10.57- 52.87 Cu; 24.23-64.11 Pb and 1.56-3.03 Fe. The degree of sediment contaminations were computed using an enrichment factor (EF) and geoaccumulation index (Igeo). The results suggested that enrichment factor and geoaccumulation values of Cd were greatest among the studied metals. Pearson's correlation indicated that effectiveness of TOC in controlling the distribution and enrichment of metals was a more important factor than that of the grain size (<63μm). The study revealed that on the basis of computed indexes, Klang River is classified as moderately polluted river

    Assessment of metals contamination in Klang River surface sediments by using different indexes

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    Surface sediments (0-5 cm) from 21 stations throughout Klang River were sampled for metal concentration as well sediment's pH, total organic carbon (TOC) and particles sizes to obtain an overall classification of metal contaminations in the area. The concentration of metals (µg∕g, Fe%, dw) were as follows: 0.57- 2.19 Cd; 31.89-272.33 Zn; 5.96-24.47 Ni; 10.57- 52.87 Cu; 24.23-64.11 Pb and 1.56-3.03 Fe. The degree of sediment contaminations were computed using an enrichment factor (EF) and geoaccumulation index (Igeo). The results suggested that enrichment factor and geoaccumulation values of Cd were greatest among the studied metals. Pearson's correlation indicated that effectiveness of TOC in controlling the distribution and enrichment of metals was a more important factor than that of the grain size (< 63µm). The study revealed that on the basis of computed indexes, Klang River is classified as moderately polluted river

    Correlation of MT levels in livers and gills with heavy metals in wild tilapia (Oreochromis mossambicus) from the Klang River, Malaysia

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    Metallothionein (MT) concentrations in gill and liver tissues of Oreochromis mossambicus were determined to assess biological response of fish to levels of some metals. Metal concentrations in gill and liver tissues of O. mossambicus ranged from 0.6 to 2.6 for Cd, 16 to 52 for Zn, 0.5 to 17 for Cu and 2 to 67 for T–Hg (all in μg/g wet weight, except for T–Hg in ng/g wet weight). Accumulation of Cd, Zn, Cu and Hg (μg/g wet weight) in the liver and gills of O. mossambicus were in the order of liver > gills. The concentrations of Cd, Zn, Cu and Hg in fish tissues were correlated with MT content. The increases in MT levels from the reference area Puchong Tengah compared to the polluted area Kampung Seri Kenangan were 3.4- and 3.8-fold for gills and livers, respectively. The results indicate that MT concentrations were tissue-specific, with the highest levels in the liver. Therefore, the liver can act as a tissue indicator in O. mossambicus in the study area

    Risk assessment of mercury contamination in surface sediment of the Klang River, Malaysia

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    Total mercury contamination in 21 stations in Klang River. T-Hg concentrations were ranged from 0.02 to 0.45 μg g-1 dry weight surface sediments. Enrichment factor (EF), and sediment quality guidelines of threshold effect level (TEL) and probable effect level (PEL) were applied to calculate the degrees of sediment contamination. The mercury EF showed the significant role of the anthropogenic inputs in sediments of Klang River. The result also determined that none of T-Hg concentrations in the sediments were as high as the PEL value, whereas mercury concentrations in some stations exceeded the TEL value

    Spatial distribution and anthropogenic assessment of heavy metals in the surface sediments of Klang River.

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    The study was conducted to quantify the concentration and distribution of metals (Cd, Zn, Ni, Cu, Pb, and Fe) in the surface sediments and to assess the status of metal contaminations in the Klang River, Malaysia. The concentrations of metals (μg/g, Fe%, dry weight) were as follows: 0.57-2.19 μg/g Cd; 31.89-272.33 μg/g Zn; 5.96-24.47 μg/g Ni; 10.57-52.87 μg/g Cu; 24.23-64.11 μg/g Pb and 1.56%-3.03% Fe. Sequential extraction technique (SET) showed that mean anthropogenic portions of metals were in the order of Zn (60.22%), Cu (56.01%), Cd (45.63%), Ni (42.08%), Pb (33.22%) and Fe (10.26%). The highest concentrations of metals (p<0.05) were found in the stations located close to industrial parks and highly populated areas. The results of the present study showed that the effectiveness of total organic carbon (TOC) contents in controlling the distribution and enrichment of metals was a more important factor compared to grain size. The study also indicated that the control of metals pollution from direct influx of domestic wastes and insufficiently treated industrial wastes in the Klang River was an important and desirable way to minimize the detrimental effects of metals

    Chemical speciation and contamination assessment of Zn and Cd by sequential extraction in surface sediment of Klang River, Malaysia

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    The concentration and chemical speciation of Cd and Zn as well as total organic carbon (TOC) were studied in surface sediments from 21 stations along Klang River. Sequential extraction technique (SET) was applied to assess the four (exchangeable, acid-reducible, oxidisable-organic and residual) fractions in surface sediment. And also, to obtain an overall classification of cadmium and zinc pollution in this area. This investigation was the first study on the basis of the chemical speciation of Cd and Zn in surface sediments of the Klang River. The total concentrations of metals were ranged (0.60–2.26 µg g− 1) for Cd and (33.26–268.24 µg g− 1) for Zn. The chemical speciation of Cd and Zn in most sampling stations were in the order of residual > acid-reducible > oxidisable-organic > exchangeable, and it showed that the Zn in Klang River surface sediments existed in the nonresistant fractions, whilst Cd existed in the resistant fraction. The degree of surface sediments contamination was determined for individual contamination factors (ICF) and global contamination factor (GCF). The result of ICF and GCF values showed that those stations located vicinity of municipal area had high potential risk to fauna and flora of the Klang River. The relationship between the concentration of cadmium and zinc at the oxidation-organic fraction with TOC in surface sediment was identified. The results showed that TOC had a positive function to complex with Cd and Zn in the surface sediment of Klang River

    Conductometric determination of formation constants of tris(2-pyridyl)methylamine and titanium (III) in water-acetonitryl mixture.

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    A conductance study of the interaction between titanium (III) cation and tris(2-pyridyl) methylamine (tpm), in water-acetonitrile mixtures was carried out at various temperatures. The formation constants of the resulting 1:1 complexes were determined from the molar conductance-mole ratio data. The stability constants of 1:1 (M:L) complexes of tpm with titanium (III) cation, the Gibbs standard free energies (ΔGc o{script}), the standard enthalpy changes (ΔHc o{script}) and the standard entropy changes (ΔSc o{script}) for the formation of these complexes in acetonitrile-water (AN-H2O) binary mixtures have been determined conductometrically. The stability constants of the complexes were obtained from fitting of molar conductivity curves using a computer program, GENPLOT

    Doxorubicin-induced renal inflammation in rats: Protective role of Plantago major

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    Objective: The aim of the present study was to evaluate the possible protective effect of Plantago major (P. major) extract against doxorubicin (DXR)-induced renal inflammation in rats. Materials and Methods: 80 male albino rats were randomly divided into 8 groups as follows: control, DXR, Ext (extract) 600, Ext1200, dexamethasone+DXR, vitamin E+DXR, Ext600+DXR, and Ext1200+DXR. Duration of the study was 35 days and DXR was intravenously injected on the 7th day of the experiment. Tumor necrosis factor-alpha (TNF-α) production and monocyte chemoattractant protein-1 (MCP-1) expression levels were assessed in the left kidney. Serum creatinine concentration and osmolarity were determined on the 1st, 14th, 21st, 28th and 35th days of the experiment. Results: DXR caused a significant increase in renal expression of MCP-1 and TNF-α production compared to control animals. Administration of dexamethasone, vitamin E and P. major extract significantly improved the expression of these inflammatory mediators compared to DXR group. Compared to day 1 in DXR group, serum osmolarity showed a significant increase on days 21, 28 and 35. Also, on these days, serum osmolarity in DXR group was significantly higher than that on the same days in control group. In Vit E+DXR and Ext 1200+DXR groups, there was no significant changes in serum osmolarity among different days of the study. However, in these groups, serum osmolarity on days 21, 28 and 35 showed a significant decrease compared to the same days in DXR group. Conclusion: Present results suggest that hydroethanolic extract of P. major protected renal tissue against DXR–induced renal inflammation

    Global, regional, and national burden of hepatitis B, 1990-2019: a systematic analysis for the Global Burden of Disease Study 2019

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