Tengku Hanidza Tengku Ismail

Spatial Geochemical Distribution and Sources of Heavy Metals in the Sediment of Langat River, Western Peninsular Malaysia

The present study employed geochemical and multivariate analyses to assess the level of heavy metals (As, Cu, Cr, Ni, Pb, and Zn) in sediment along the lower reaches of the Langat River. The sediment samples were digested and analyzed for total metals by an inductively coupled plasma-mass spectrometry (ICP-MS). Selected physicochemical parameters such as pH, redox potential (Eh), electrical conductivity (EC), salinity, organic matter and cation exchange capacity (CEC) were also determined. The metal concentration from this study area was compared with interim sediment quality guidelines (ISQG). Most sediment samples did not exceed the ISQG. Geo-accumulation index (Igeo) revealed that certain sampling stations were classified as strongly polluted with respect to As and classified as moderately polluted for Pb. Based on the enrichment factor (EF) values, most sampling stations were categorized as ‘very severely enriched to extremely severely enriched for As and only 3% were moderately enriched. For Pb, pH, Eh, and CEC pose considerable influence on the composition of heavy metal in the sediment as confirmed by Pearson correlation. The hierarchical cluster analysis (HCA) revealed that sediment in the study area could be divided into two major clusters. Cluster 1 was mainly affected by the agricultural and industrial activities while Cluster 2 was heavily affected by seawater. The forensic investigation via the use of geostatistical and geochemical approaches revealed two pollution sources: (i) man-made (agricultural and industrial activities), and (ii) natural processes (seawater intrusion and geological weathering). The quantification of heavy metal concentrations thus provides a better understanding of the potential ecological risks and contamination status of the sediment. The vulnerable areas identified in this study should be given the highest priority for mitigation measures in order to alleviate pollution from industries and agriculture areas. The incorporation of source apportionment method to further understand the dynamics of environmental processes is recommended for future studies to assist in identifying possible high pollution-risk areas.

Elemental hydrochemistry assessment on its variation and quality status in Langat River, Western Peninsular Malaysia

This paper discusses the hydrochemistry variation and its quality status in Langat River, based on the chemistry of major ions, metal concentrations and suitability for drinking purposes. Water samples were collected from 30 different stations to assess their hydrochemical characteristics. The physico-chemical parameters selected were temperature, electrical conductivity, total dissolved solids (TDS), salinity, dissolved oxygen , pH, redox potential, HCO3, Cl, SO4, NO3, Ca, Na, K, Mg, 27Al, 138Ba, 9Be, 111Cd, 59Co, 63Cu, 52Cr, 57Fe, 55Mn, 60Ni, 208Pb, 80Se and 66Zn to investigate the variation of the constituents in the river water. Most of the parameters comply with the Drinking Water Quality Standard of the World Health Organization and the Malaysian National Standard for Drinking Water Quality by the Malaysia Ministry of Health except for EC, TDS, Cl, HCO3, SO4, Na, Mg, Al, Fe and Se. The results show that the Langat River is unsuitable for drinking purposes directly without treatment.

Virtual water trade in industrial products: evidence from Malaysia

Virtual water embodied in international trade is equivalent to nearly one-third of global water withdrawal, confirming that trade plays a significant role in redistributing global water resources. This paper extends a virtual water analysis by measuring the extent to which virtual water embodied in traded industrial products affects the distribution of global virtual water. The distribution of global virtual water can be improved if trade in industrial products promotes virtual water outflows from water-abundant to water-scarce countries. Analyses were performed using an input–output model that can decompose water consumption into domestic demand and exports by destinations of trade. Focusing on Malaysia, the results indicate that trade in industrial products between Malaysia and its main trading partners have a limited capacity to improve the distribution of global virtual water. This limitation can be due to two reasons. Firstly, exports of Malaysian industrial products are mainly driven by less water-intensive sectors. Therefore, the amount of virtual water that outflows into other countries is also low. Secondly, trade in Malaysian industrial products largely involves water flows with other water-abundant countries. Only several water-scarce countries benefit from virtual water trade in industrial products with Malaysia, namely the Netherlands, Australia and China.

The Accumulation of Fe, Pb, Zn, Ni and Cd in Nerita lineata and Thais bitubercularis Obtained from Tanjung Harapan and Teluk Kemang, Malaysia

The concentrations of selected heavy metals (Fe, Pb, Zn, Ni and Cd) were determined in the soft tissues and shells of two mollusc, namely, Nerita lineata and Thais bitubercularis taken from Tanjung Harapan and Teluk Kemang, Malaysia. Samples were collected in April 2012 and analysed using inductively coupled plasma mass spectrometry (ICP-MS). Fe is the most abundant metal in the tissue and shell compared to the rest of the metals. The concentrations of heavy metals in the soft tissues of Nerita lineata taken from Tanjung Harapan follow this order: Fe > Zn > Ni > Cu > Cd while in Thais bitubercularis, the metal concentrations were higher following the order of Fe > Zn > Cu > Ni > Cd. The samples taken from Teluk Kemang were higher and exhibited different trend for both organisms. For Nerita lineata, the concentrations were Fe > Cu > Zn > Ni > Cd > Pb while in the Thais bitubercularis the order was Fe > Zn > Cu > Cd > Ni > Pb. There was evidence of spatial difference where Fe was detected in large amount compared to other metals for both locations. Cd has the potential to be accumulated in Nerita lineata whereas for the T. bitubercularis Cu, Cd, and Zn were accumulated in the soft tissues.

Concerns on the Threat of Environmental Hazards to Human and Environment in Malaysia: An Exploratory Analysis

A total of 1224 university students from Universiti Putra Malaysia, Malaysia, were asked to give a quantitative judgment about the threat to human and the environment with possible answers ranging from “no threat at all” (1) to “extreme threat” (7). This study was carried out from December 2007 to February 2008. Results from this study showed that students tend to rank ‘threat ‘as “high” for hazards familiar to them. The mean score for top five hazards were nuclear technology (6.07), global warming (6.04), drugs (5.92), earthquake (5.79), and tsunami (5.78). On the other hand, unfamiliar hazard such as genetic technology (4.74) and handphone (4.41) were perceived as ‘least threatening’. The role of gender, year of study, race, and academic discipline on risk perception were also examined. Results show that gender plays the biggest role in shaping students’ risk opinion. Female students were more concerned about threat of risk than male students. The differences in opinion follow this order: gender > year of study > race > academic discipline.

Pharmaceuticals residues in selected tropical surface water bodies from Selangor (Malaysia): Occurrence and potential risk assessments

This study investigated the occurrence of nine pharmaceuticals (amoxicillin, caffeine, chloramphenicol, ciprofloxacin, dexamethasone, diclofenac, nitrofurazone, sulfamethoxazole, and triclosan) and to evaluate potential risks (human health and ecotoxicological) in Lui, Gombak and Selangor (Malaysia) rivers using commercial competitive Enzyme-Linked Immunosorbent Assay (ELISA) kit assays. Physicochemical properties of these rivers showed the surface samples belong to Class II of Malaysian National Water Quality Standards which requires conventional treatment before consumption. All the pharmaceuticals were detected in all three rivers except for triclosan, dexamethasone and diclofenac which were not detected in few of sampling locations in these three rivers. Highest pharmaceutical concentrations were detected in Gombak river in line of being as one of the most polluted rivers in Malaysia. Ciprofloxacin concentrations were detected in all the sampling locations with the highest at 299.88 ng/L. While triclosan, dexamethasone and diclofenac concentrations were not detected in a few of sampling locations in these three rivers. All these nine pharmaceuticals were within the levels reported previously in literature. Pharmaceutical production, wastewater treatment technologies and treated sewage effluent were found as the potential sources which can be related with pharmaceuticals occurrence in surface water samples. Potential human risk assessment showed low health risk except for ciprofloxacin and dexamethasone. Instead, ecotoxicological risk assessment indicated moderate risks were present for these rivers. Nevertheless, results confirmation using instrumental techniques is needed for higher degree of specificity. It is crucial to continuously monitor the surface water bodies for pharmaceuticals using a cost-effective prioritisation approach to assess sensitive sub-populations risk.

Does Trade in Industrial Products have the Potential to Improve Distribution of Global Virtual Water

Virtual water refers to the amount of water used in the production of a product (a commodity, goods or services). This study examines the extent to which trade in industrial products (i.e. mining and manufacturing) between Malaysia and other countries will affect the distribution of water in water-abundant and water-scarce countries. Analyses of virtual water for 67 industrial sectors are conducted using the input–output model. This model has the ability to decompose virtual water content in the domestic demand and exports as well as virtual water import. This model also distinguishes virtual water flows (export and import) by trade destinations. Results show that resource based products are water intensive whereas electronics and electrical, machinery and equipment, and transport equipment are water non-intensive. Exports explain more than two-thirds of water consumption. Malaysia exports water non-intensive products and import water intensive products. The potential role of trade in industrial products as a policy instrument for global water distribution is limited. First, since the production of industrial products is essentially water non-intensive, thus exports of these products are not associated with large amount of water outflows. Second, trade in industrial products involves water flows among the water-abundant countries but not in water scarce countries.