Hazzeman Haris

Application of geoaccumulation index and enrichment factors on the assessment of heavy metal pollution in the sediments

An investigative study was carried out in Langat River to determine the heavy metal pollution in the sediment with 22 sampling stations selected for the collection of sediment samples. The sediment samples were digested and analyzed for extractable metal (48Cd, 29Cu, 30Zn, 33As, 82Pb) using the Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Parameters, such as pH, Eh, electrical conductivity (EC), salinity, cation exchange capacity (CEC) and loss on ignition (LOI) were also determined. The assessment of heavy metal pollution was derived using the enrichment factors (EF) and geoaccumulation index (Igeo). This study revealed that the sediment is predominantly by As > Cd > Pb > Zn > Cu. As recorded the highest EF value at 187.45 followed by Cd (100.59), Pb (20.32), Zn (12.42) and Cu (3.46). This is similar to the Igeo, which indicates that the highest level goes to As (2.2), exhibits moderately polluted. Meanwhile, Cd recorded 1.8 and Pb (0.23), which illustrates that both of these elements vary from unpolluted to moderately polluted. The Cu and Zn levels are below 0, which demonstrates background concentrations. The findings are expected to update the current status of the heavy metal pollution as well as creating awareness concerning the security of the river water as a drinking water source.

The geoaccumulation index and enrichment factor of mercury in mangrove sediment of Port Klang, Selangor, Malaysia

Mangrove areas are important to the ecosystem. One of its crucial functions is as a sink of pollutants, especially metal ions. However, the accumulation of metals in mangrove sediment can generate negative impacts on plant growth, microbial activity, and soil fertility. Apart from that, the severity of the impact is highly influenced by the type of metal found in the sediment and the quality of sediment itself. One of the metals that have adverse effects on the environment is mercury. The objectives of this study are to determine the concentration and distribution of mercury and to assess the enrichment of mercury in Port Klang mangrove sediment by using geoaccumulation index and enrichment factor. Sediment samples were collected from 30 sampling points that cover Langat River and Klang River estuaries, Lumut Straits, Pulau Klang, and Pulau Indah. During sampling, water parameters such as pH, salinity, electrical conductivity, and total dissolved solids were measured in situ, whereas the total mercury in sediment samples was determined at the laboratory using inductively coupled plasma mass spectrometry. In this study, mercury was found to be concentrated along Lumut Strait especially in the mixing zone near the confluence of Langat River and at the jetty to Pulau Ketam. The geoaccumulation index and enrichment factor (calculated using logarithmized data of the reference element) found that three stations were enriched with mercury. In addition, geoaccumulation index was also observed to be more objective compared to enrichment factor whose results were influenced by the concentration of reference element used.

Geoaccumulation and distribution of heavy metals in the urban river sediment

Abstract Current study presents the application of chemometric techniques to comprehend the interrelations among sediment variables whilst identifying the possible pollution source at Langat River, Malaysia. Surface sediment samples (0-10 cm) were collected at 22 sampling stations and analyzed for total metals ( 48 Cd, 29 Cu, 30 Zn, 82 Pb), pH, redox potential (Eh), salinity, electrical conductivity (EC), loss on ignition (LOI) and cation exchange capacity (CEC). The principal component analysis (PCA) scrutinized the origin of environmental pollution by various anthropogenic and natural activities: four principal components were obtained with 86.34% (5 cm) and 88.34% (10 cm). Standard, forward and backward stepwise discriminant analysis effectively discriminate 2 variables (84.06%) indicating high variation of heavy metals accumulation at both depth. The cluster analysis accounted for high input of Zn and Pb at LA8, LA 10, LA 11 and LA 12 that mergers three (5 cm) and four (10 cm) into clusters. This is consistent with the contamination factor ( C f ) that shows high Cd (LA 1) and Pb (LA 7, LA 8, LA 10, LA 11 and LA 12) contaminations at 5cm. These indicate that Pb and Zn are the most bioavailable metals in the sediment with significant positive linear relationship at both sediment depths. Therefore, this approach is a good indication of environmental pollution status that transfers new findings on the assessment of heavy metals by interpreting large complex datasets and predicting the fate of heavy metals in the sediment.

Erratum to: Distribution of metals and quality of intertidal surface sediment near commercial ports and estuaries of urbanized rivers in Port Klang, Malaysia

Thirty intertidal surface sediment samples with replicates were collected from Port Klang and the concentration of metals, sediment particle size and amount of organic matter were determined. The mean metal concentrations as in descending order were: Mn (136.991 ± 46.800 mg kg−1) > Zn (48.249 ± 25.790 mg kg−1) > Cr (24.175 ± 4.739 mg kg−1) > Pb (15.560 ± 5.475 mg kg−1) > Ni (6.860 ± 1.693 mg kg−1) > Cu (6.777 ± 9.064 mg kg−1) > Co (1.854 ± 0.352 mg kg−1) > Cd (0.074 ± 0.054 mg kg−1). The Klang River and the Langat River were identified as the point of entry for metals to the Lumut Strait. Metal accumulations were found to occur near or within the Klang and the Langat River estuary and also along the Lumut Strait. The enrichment factor and the geo-accumulation index revealed enrichment of Cd, Cu, Pb and Zn by anthropogenic sources. In addition, Cu concentration at two stations located near a commercial jetty, marina and shipyard had also exceeded the ISQG level by the Canadian Interim Marine Sediment Quality Guideline. Principal component analysis showed that concentration of Cd, Cu, Pb and Zn was more dependent on Klang River, as compared to Langat River which had more influence on the concentration of Co, Cr, Mn and Ni. It was shown that presence of clay, silt and organic matter favored metal retention in the sediment.

The levels of mercury, methylmercury and selenium and the selenium health benefit value in grey-eel catfish (Plotosus canius) and giant mudskipper (Periophthalmodon schlosseri) from the Strait of Malacca.

The present study examined the concentrations of mercury (Hg), methylmercury (MeHg), and selenium (Se) in the multiple tissues of the Plotosus canius and Periophthalmodon schlosseri collected from the Strait of Malacca. The mean value in mg kg(-1) of Hg (P. canius: 0.34 ± 0.19; P. schlosseri: 0.32 ± 0.18) and MeHg in muscle (P. canius: 0.14 ± 0.11; P. schlosseri: 0.17 ± 0.11) were below the Codex general standard for contaminants and toxins in food and feed (CODEX STAN 193-1995), the Malaysian Food Regulation 1985 and the Japan Food Sanitation Law. For P. canius, the liver contained the highest concentrations of Hg (0.48 ± 0.07 mg kg(-1)) and MeHg (0.21 ± 0.00 mg kg(-1)), whereas for P. schlosseri, the gill contained the highest concentrations of Hg (0.36 ± 0.06 mg kg(-1)) and MeHg (0.21 ± 0.05 mg kg(-1)). The highest concentration of (80)Se (mg kg(-1)) was observed in the liver of P. canius (20.34 ± 5.68) and in the gastrointestinal tract (3.18 ± 0.42) of P. schlosseri. The selenium:mercury (Se:Hg) molar ratios were above 1 and the positive selenium health benefit value (HBVSe) suggesting the possible protective effects of Se against Hg toxicity. The estimate weekly intakes (EWIs) in μg kg(-1) body weight (bw) week(-1) of Hg (P. canius: 0.27; P. schlosseri: 0.15) and MeHg (P. canius: 0.11; P. schlosseri: 0.08) were found to be lower than the provisional tolerable weekly intake established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). Based on the calculated EWIs, P. canius, and P. schlosseri were found to be unlikely to cause mercury toxicity in human consumption.

Mercury Distribution in Port Klang Mangrove and Estuarine Sediment

Mangrove and estuarine areas are important to the ecosystem and can act as a sink of pollutants, especially metal ions. However, the accumulation of metals in sediment can cause negative impacts on plant growth, microbial activity and soil fertility. The severity and nature of the impact is highly influenced by the type of metal found in the sediment. One of the metals that have adverse effects on the environment is mercury. Therefore, the objectives of this study are to determine the mercury concentration and its distribution in the study area. Sediment samples were collected from 30 sampling points that cover Langat River and Klang River estuaries, Lumut Straits, Pulau Klang and Pulau Indah in Selangor, Malaysia. The extractable mercury in sediment samples was determined at the laboratory using inductively coupled plasma mass spectrometry (ICP-MS). In this study, mercury was found to be concentrated along Lumut Strait especially in the mixing zone near the confluence of Langat River.