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This study determined the levels of Cd, Cu, Fe, Ni, and Zn in the soft tissues and shells of barnacles (Balanus sp.) collected from the Kuala Juru, Sebatu, Sg. Ayam and Kg. Pasir Puteh, Peninsular Malaysia, obtained in 2008. The metal concentrations (μg/g dry weight) in the soft tissues of Balanus sp. received from four sites in Peninsular Malaysia ranged from 2.93-4.17 for Cd, 20.2-92.5 for Cu, 480-1193 for Fe, 6.40-18.0 for Ni, and 224-414 for Zn. Based on the present data, the trace metal bioavailability’s to the Balanus in all the populations, especially in a known polluted site at Kg. Pasir Puteh is low. Overall, this preliminary baseline data can be used for regular ecological monitoring for the effective management of the coastal area in Malaysia.

The purpose of this paper is to discuss Cu and Zn concentrations in Perna viridis soft tissues from the western and eastern parts of Johore Singapore Causeway. The polluted eastern portion of the Causeway had greater levels of Cu and Zn in different areas of the soft tissues of mussels than the western part. This indicated the eastern section of the semi-enclosed Causeway had higher Cu and Zn bioavailability than the western part. With some reports of high metal levels in the eastern part of the Causeway from 2015 to 2018, it is predicted that there will be a plausible constant source of anthropogenic metal contamination in the eastern part of the Causeway beyond 2030 if anthropogenic activities are not effectively controlled.

Due to extremely high rates of evaporation and low precipitation in the Persian Gulf, discharges from desalination plants (DPs) can lead to ecological stresses by increasing water temperatures, salinities, and heavy metal concentrations, as well as decreasing dissolved oxygen levels. We discuss the potential ecological impacts of DPs on marine organisms and propose mitigating measures to reduce the problems induced by DPs discharges. The daily capacity of DPs in the Persian Gulf exceeds 11 million m3 per day, which is approximately half of global daily freshwater production; multistage flash distillation (MSF) is the dominant desalination process. Results from field and laboratory studies indicate that there are potentially serious and chronic threats to marine communities following exposure to DP discharges, especially within the zoobenthos, echinodermata, seagrasses, and coral reefs. DP discharges can lead to decreases in sensitive species, plankton abundance, hard substrate epifauna, and growth rates of seagrasses. However, the broad applicability of any one of these impacts is currently hard to scale because of the limited number of studies that have been conducted to assess the ecological impacts of DP discharge on Persian Gulf organisms. Even so, available data suggest that appropriately sited, designed, and operated DPs combined with current developments in impingement and entrainment reduction technology can mitigate many of the negative environmental impacts of DPs.

This study aimed to investigate the concentrations of copper (Cu), zinc (Zn), nickel (Ni), lead (Pb) and iron (Fe) in different parts of guava (pulps, peels and seeds) and its topsoil collected from Kluang, Malaysia, and to assess their effects on human health. The level of metals was determined using acid digestion method and atomic absorption spectrometry. The result showed that the concentrations of Cu, Zn and Pb in all parts of guava were above the World Health Organization (WHO) permissible limits. However, the value of heavy metals in the topsoil were below the WHO limit. The concentration order of the metals in the guava's pulps was Fe > Cu > Zn > Pb > Ni. The contamination factor (Cf ) calculated from the topsoil were low for Cu, Zn and Ni and moderate for Pb. However, potential ecological risk (Er) of individual metal ranged from 0.25-7.58 for Cu, Zn, Pb and Ni was low. The potential non-carcinogenic health risk for consumers was assessed using estimated daily intake (EDI) and target hazard quotient (THQ). The contribution of heavy metals to the EDI for all consumers followed the order of Fe > Cu > Zn > Pb > Ni. The THQ values are all below 1 for all five metals tested, indicating no potential risk to the consumers. We suggest that the Kluang's guava is safe to consume. However, regular monitoring and human health risk assessment of heavy metals in the guava is recommended to be carried out.

The objective of this commentary is to promote the use of bivalves as biomonitors, which is a part of the continual efforts of the International Mussel Watch. This commentary is an additional discussion on “Bivalve mollusks in metal pollution studies: From bioaccumulation to biomonitoring” by Zuykov et al., published in Chemosphere 93, 201–208. The present discussion can serve as a platform for further insights to provide new thoughts and novel ideas on how to make better use of bivalves in biomonitoring studies. The certainty of better and more extensive applications of mollusks in environmental monitoring in the future is almost confirmed but more studies are urgently needed. With all the reported studies using bivalves as biomonitors of heavy metal pollution, the effectiveness of using Mussel Watch is beyond any reasonable doubts. The challenge is the development of more accurate methodologies for of heavy metal data interpretation, and the precision of the biomonitoring studies using bivalves as biomonitors, whether in coastal or freshwater ecosystems. Lastly, inclusion of human health risk assessment of heavy metals in commercial bivalves would make the research papers of high public interest.

The aim of the present study was to assess the efficacy of All Cosmos Industries (ACI) bio-organic and bio-chemical fertilizers and ACI N-Fixer (N-Bio Booster) on the paddy yields based on the field trial plots at Langkat, Medan, Indonesia. This application of ACI bio-organic fertilizer (NPK 5/5/5) and ACI bio-chemical (NPK 15/15/15) fertilizer and ACI N-Fixer tests were conducted at the paddy farm at Langkat from May-October 2018. This study employed a factorial randomized complete block design which consisted of two factors, namely: Factor I with four types of fertilizers while Factor II consisted of two paddy varieties (Inpari 30 and Inpari 32). Overall, the filled grains in the ACI treatments are significantly (P< 0.05) higher than those in the control treatments that used Normal Chemical Compound NPK. Overall, total weight per meter² (368-617g) in ACI treatments are also significantly (P< 0.05) higher than those (319-371g) in the control treatments. At harvesting time at 105 days after transplanting, significantly higher (P< 0.05) colony counts (13-15 x 106 CFU/mL) (for ACI treatments), than those (8 x 106 CFU/mL) in the controls positively indicated higher total yields of paddy grains per hectare. It was found that the application of ACI bio-organic and bio-chemical fertilizers and ACI N-Fixer can improve paddy yields of the two rice varieties, between 16.4-38.2% (up to 5.75 MT/ha), in the field trial plots at Langkat. These commercial fertilizers play an imperative role in refining the soil fertility and thereby can increase the yield of rice production. Therefore, it is highly recommended that ACI bio-organic and ACI bio-chemical fertilizers and ACI N-Fixer (N-Bio Booster) can be employed to increase the paddy yield in this region.

Haqal is a small city located in north-western part of Arabian Peninsula. The anthropogenic activities in this region are evident. This region is targeted for future development by Saudi government. In this study, the surface sediment of Haqal coastal waters were analysed for heavy metals (Cd, Cu, Fe, Ni, Pb, and Zn). The total concentration (mg/kg dry weight) ranged from 0.012-0.186 for Cd, 0.582-1.13 for Cu, 0.51-2.18 for Ni, 0.68-2.64 for Pb, 1.97-4.52 for Zn while for Fe, it ranges from 0.155 to 0.254%. Based on ecological risk assessment results, the values of PERI were categorised as 'low ecological risk', thus all sampling sites were unpolluted with heavy metals. Despite that, this monitoring study had a positive result for non-heavy metal pollution, future mitigation of the heavy metal pollution in coastal areas of Tabuk should be given priority by the authorities. The present study can be considered as the first effort to monitor the pollution of heavy metals in Haqal. This provides baseline information for future ecotoxicological studies which can involve application of bioindicators to assess the quality of the marine environment in this region.

The aim of this paper is to determine and discuss the Concentrations of Copper (Cu) in the different soft tissues of Perna viridis and surface sediments collected from western and eastern parts of Johore Singapore Causeway. In general, it is found that the different tissues of eastern mussel populations were found to have significant (p < 0.05) higher Cu levels than those in the western mussel populations. This indicated higher Cu bioavailability in the eastern part of causeway than that in the western part. The geochemical fractions (except for oxidizable-organic fraction) showed significant (p < 0.05) higher Cu levels in the eastern sediments than those in the western part of the causeway. This indicated higher Cu contamination in the eastern part of causeway than that in the western part. With consistent scientific reports of high metal levels in the eastern part of causeway between 2015-2018, it is predicted that there is a plausible constant source of anthropogenic metal contamination at the eastern part of the causeway beyond 2020 should there is no drastic effective control of the anthropogenic activities.

The intertidal and urban waters of west Peninsular Malaysia are interesting area for ecotoxicological studies because they receive wastes due to agricultural municipal and industrial wastes along the west coast of Peninsular Malaysia Surface water samplings were conducted from the intertidal coastal waters and from urban rivers drainages from northern to southern parts of the west coastal areas of Peninsular Malaysia between January and April These nitrate levels in the south western part ranged from mg L while those in the north western part ranged from to mg L These nitrate levels in these intertidal waters were much lower than those found for urban drainages to mg L of Peninsular Malaysia Overall the mean values for the nitrate concentrations mg L follow Urban drainages gt north western intertidal gt south western intertidal The results showed the occurrence of nitrate contaminatin in the urban area due to human induced activities such as domestic wastes Albeit this study revealed no serious threat of nitrate contamination in the urban and intertidal coastal waters compared to the safety limits continuous monitoring should be carried out on the concentrations of nitrate in the aquatic ecosystem of Peninsular Malaysia since it could be a harmful nutrient to living organisms if presented in excessive concentrations

This paper reviews the potentials and challenges of using Oil Palm Biomass Wastes (OPBW) as Renewable Energy (RE) source in Malaysia. The OPBW mainly includes Palm Oil Mill Effluent (POME) and Empty Fruit Bunches (EFB). From the present review, the major potentials of OPBW consist of their large availability, being a major sources of lignocellulosic materials for industrial, being economically viable, being a solution to the disposal problem and cost-benefit. The challenges of using OPBW as RE source are being a high dependency on the availability of the OPWB, unfair subsidies given to RE based fuel, the use of POME that produces methane, substantial amount of under-utilization of lignocellulosic wastes from OPBW, the need for further studies on the correct selection of generation plant size, and not economically competitive. Overall, the challenge is to make the OPBWs as a reliable, profitable and sustainable RE industry. Based on the present review mainly from Malaysia, there are definite potentials/advantages of using OPBW as RE source in Malaysia. Ways and suggestions on these practical issues on how to reduce problems facing the use of OPBW as RE source in Malaysia should be investigated and addressed before the large scale utilization of OPBW as RE source can be anticipated in Malaysia.

The heavy metal (HM) pollution in sediment is of serious concern, particularly in the Red Sea environment. This study aimed to review and compile data on the concentrations of four HMs (Cd, Cu, Pb, and Zn) in the coastal surface sediments from the Red Sea, mainly from Saudi Arabia, Egypt, and Yemen, published in the literature from 1992 to 2021. The coastal sediments included those from mangrove, estuaries, and intertidal ecosystems. It was found that the mean values of Cd, Cu, Pb, and Zn in coastal Red Sea sediments were elevated and localized in high human activity sites in comparison to the earth upper continental crust and to reference values for marine sediments. From the potential ecological risk index (PERI) aspect, 32 reports (47.1%) were categorized as ‘considerable ecological risk’ and 23 reports (33.8%) as ‘very high ecological risk’. From the human health risk assessment (HHRA) aspect, the non-carcinogenic risk (NCR) values (HI values < 1.0) of Cd, Cu, Pb, and Zn represented no NCR for the ingestion and the dermal contact routes for sediments from the Red Sea countries. The reassessment of the HM data cited in the literature allowed integrative and accurate comparisons of the PERI and HHRA data, which would be useful in the management and sustainable development of the Red Sea area, besides being a helpful database for future use. This warrants extensive and continuous monitoring studies to understand the current and the projected HM pollution situation and to propose possible protective and conservative measures in the future for the resource-rich Red Sea ecosystem.

This study aimed to analyse ten trace metal concentrations in the edible part of the freshwater clam Corbicula javanica and to provide a critical assessment of the potential risks to human health through consumption of this clam as food based on well-established indices and food safety guidelines. The clams were captured from a pristine original site and transplanted to other sites with different environmental qualities. The trace metal levels in the edible total soft tissue (TST) of the clam were below those of the food safety guidelines referred to except for Pb, which exceeded the permissible limit set by the European Commission (2006) and the US Food and Drug Administration/ Center for Food Safety and Applied Nutrition), Interstate Shellfish Sanitation Conference. (USFDA/CFSAN, ISSC) (2007). The estimated daily intake (EDI) values of the clam were found to be lower than the oral reference dose and the calculated target hazard quotient (THQ) and total THQ were found to be less than 1. Therefore, in conclusion, the human health risk for consumption of TST of C. javanica at both average and high-level were insignificant regardless of the environment it was exposed to.

Fifty-five core marine sediments from three locations at South China Sea and one location each at Sulu Sea and Sulawesi Sea of coastal East Malaysia were analyzed for heavy metals by instrumental neutron activation analysis and inductively coupled plasma mass spectroscopy. The enrichment factor and the modified degree of contamination were used to calculate the anthropogenic and pollution status of the elements in the samples. The enrichment factor of As, Cd, Cr, Cu, Ni, Pb, and Zn varied from 0.42-4.26, 0.50–2.34, 0.31–0.82, 0.20–0.61, 0.91–1.92, 0.23–1.52, and 0.90–1.28, respectively, with the modified degree of contamination values below 0.6. Comparative data showed that coastal East Malaysia has low levels of contamination.

Since 1990s until today, the Asia-Pacific Mussel Watch approach has been widely used for biomonitoring purpose in Malaysia by using the green-lipped mussel Perna viridis in particular. This paper reviewed the concentrations of heavy metals (Cd, Cu, Pb and Zn), Linear Alkylbenzenes (LABs), Polycyclic Aromatic Hydrocarbons (PAHs), phenolic Endocrine Disrupting Chemicals (EDCs) [nonylphenol (NP), octylphenol (OP), and bisphenol A (BPA)] and organochlorine (OC) compounds (PCBs, DDTs, CHLs, HCHs and HCB) in nine mussel populations collected in 1998 (because I involved in the sampling field trip when I was a trainee researcher) from the coastal waters of Malaysia. In fact, all of these data were published separately in five different peer-reviewed journals in the literature (see Yap et al. [6,7]; Tsutsumi et al. [14]; Isobe et al. [15]; Monirith et al. [16]). Since they discussed only based on the group of contaminants which they focused upon, this review paper aimed to see a holistic picture and understanding of the impacts of the different chemical contaminants in relation to the description of the sampling sites. Based on seven mussel populations with complete 11 chemicals (ranging from heavy metals, LABs, PAHs, phenolic EDCs and OCs), a dendrogram was established using single linkage cluster analysis. A dendrogram was established using single linkage cluster analysis showing two major subclusters. The first subcluster comprised Tanjung Rhu, Trayong, Kuala Penyu and Pasir Panjang populations, indicating relatively uncontaminated conditions while the other subcluster consists of Penang, Kg. Pasir Puteh and Anjung Batu which indicated contaminated conditions as it is well supported by the elevated levels of some chemicals. The subcluster combining Penang and Kg. Pasir Puteh populations were mainly due to the elevated levels of LABs and PAHs in both sites while Kg. Pasir Puteh also had elevated levels of Cu, Pb, PCBs and CHLs. Anjung Batu, which is also clustering together with Penang and Kg. Pasir Puteh population can be explained by its elevated levels of three OC compounds namely DDTs, CHLs and HCHs.

The spatial distribution of 19 polycyclic aromatic hydrocarbons (tPAHs) was quantified in aquacultures located in intertidal mudflats of the west coast of Peninsular Malaysia in order to investigate bioaccumulation of PAH in blood cockles, Anadara granosa (A. granosa). Fifty-four samples from environmental matrices and A. granosa were collected. The sampling locations were representative of a remote area as well as PAH-polluted areas. The relationship of increased background levels of PAH to anthropogenic PAH sources in the environment and their effects on bioaccumulation levels of A. granosa are investigated in this study. The levels of PAH in the most polluted station were found to be up to ten-fold higher than in remote areas in blood cockle. These high concentrations of PAHs reflected background contamination, which originates from distant airborne and waterborne transportation of contaminated particles. The fraction and source identification of PAHs, based on fate and transport considerations, showed a mix of petrogenic and pyrogenic sources. The relative biota-sediment accumulation factors (RBSAF), relative bioaccumulation factors from filtered water (RBAFw), and from suspended particulate matter (SPM) (RBAFSP) showed higher bioaccumulations of the lower molecular weight of PAHs (LMWs) in all stations, except Kuala Juru, which showed higher bioaccumulation of the higher molecular weight of PAHs (HMWs). Calculations of bioaccumulation factors showed that blood cockle can accumulate PAHs from sediment as well as water samples, based on the physico-chemical characteristics of habitat and behaviour of blood cockles. Correlations among concentrations of PAHs in water, SPM, sediment and A. granosa at the same sites were also found. Identification of PAH levels in different matrices showed that A. granosa can be used as a good biomonitor for LMW of PAHs and tPAHs in mudflats. Considering the toxicity and carcinogenicity of PAHs, the bioaccumulation by blood cockles are a potential hazard for both blood cockles and their consumers.

The present study aimed to assess the effects of anthropogenic activities on the heavy metal levels in the Langat River by transplantation of Corbicula javanica. In addition, potential ecological risk indexes (PERI) of heavy metals in the surface sediments of the river were also investigated. The correlation analysis revealed that eight metals (As, Co, Cr, Fe, Mn, Ni, Pb and Zn) in total soft tissue (TST) while five metals (As, Cd, Cr, Fe and Mn) in shell have positively and significantly correlation with respective metal concentration in sediment, indicating the clams is a good biomonitor of the metal levels. Based on clustering patterns, the discharge of dam impoundment, agricultural activities and urban domestic waste were identified as three major contributors of the metals in Pangsun, Semenyih and Dusun Tua, and Kajang, respectively. Various geochemical indexes for a single metal pollutant (geoaccumulation index (I geo), enrichment factors (EF), contamination factor (C f) and ecological risk (Er)) all agreed that Cd, Co, Cr, Cu, Fe, Mn, Ni and Zn are not likely to cause adverse effect to the river ecosystem, but As and Pb could pose a potential ecological risk to the river ecosystem. All indexes (degree of contamination (C d), combined pollution index (CPI) and PERI) showed that overall metal concentrations in the tropical river are still within safe limit. River metal pollution was investigated. Anthropogenic activities were contributors of the metal pollution. Geochemical indexes showed that metals are within the safe limit.

This study evaluates the impact of anthropogenic activities on the Shahrood River using water physico-chemical variables and macroinvertebrates data sets obtained over a period of 12 months between February 2012 and February 2013 at 8 sampling sites. Biotic indices i.e. FBI and BMWP based on macroinvertebrates and physico-chemical indices (MPI, HPI and NSF-WQI) were employed to evaluate the water quality status in connection with natural- and human-induced pressures. Based on physico-chemical indices, water quality was categorized as low polluted level and it is suitable for drinking purposes. The water quality based on biotic indices was related to the anthropic activities; a clear deterioration of the water quality was observed from upstream to downstream sites. The water quality along the river changed from very good (class I; reference sites) to good (class II; midstream sites) and turned into moderate (class III) and poor (class IV) quality (downstream sites). These findings indicate that biotic indices are more powerful indicators in assessing water quality than physico-chemical indices. Allocapnia, Glossosoma and Hesperoperla were exclusively related to least disturbed sites, and Naididae, Orthocladiinae and Ecdyonurus were found in sites showing notable degradation. Our results recommended that the use of macroinvertebrates could be employed as a cost-effective tool for biomonitoring and controlling of polluted riverine ecosystems in the Middle East. Finally, the results from this study may be useful not only for developing countries, but also for any organization struggling to use macroinvertebrate based indices with restricted financial resources and knowledge.

Distributions of Cd, Cu, Pb, and Zn in the surface sediments from two sites of the Kuala Gula Bird Sanctuary, Malaysia were monitored for a period of 6 months from October 2006 to March 2007. In December 2006, the concentration of Zn in one location was significantly (p

Horseshoe crabs (Tachypleus gigas) were collected from intertidal sites of the polluted Juru River (Penang) and the relatively unpolluted Sepang Besar River (Selangor) in September and December 2007. They were dissected into six parts namely carapace, muscle, telson, leg, operculum and gills. For each site, different tissues from the horseshoe crabs were determined for the concentrations of Cd, Cu, Ni, Fe, Pb and Zn in them. Gills accumulated the highest concentrations of Cu, Cd, Fe, Ni and Pb. Muscles were found to have the highest concentrations of Zn. Most distinctively, the concentrations of Cu, Ni and Zn in the muscles of the Juru River population were significantly (P< 0.05) higher than those from the Sepang Besar River, indicating that the Juru River had higher contaminations and bioavailabilities of these metals than the Sepang Besar River. This conclusion was also well supported by the sediment data. These results suggest that T. gigas (especially the muscle) is a potential biomonitor of Cu, Ni and Zn contaminations and bioavailabilities in tropical intertidal areas.

Distribution of polycyclic aromatic hydrocarbons (PAHs) was determined in green mussels (Perna viridis) from various sites in coastal waters of Peninsular Malaysia between August 2004 and January 2007, in order to assess contamination by petroleum hydrocarbons. The range of ∑PAHs detected in mussels was from 766 to 110500 (ng/g lipid wt.). High concentrations of PAHs were found in mussel tissues collected near Penang Bridge. The ratios of methyl phenanthrenes to phenanthrene (∑MP/P ratio) for Penang, Kg. Pasir Puteh and Tebing Runtuh (Johore Straits) were greater than 2, indicating extensive input of petrogenic PAHs. The results indicated that male individuals elevated more considerable concentrations of PAHs in their soft tissues in comparison to female individuals. The results of independent sample T-test showed that there were no significant differences (p > 0.05) between male and female mussels analysed in the Pasir Panjang station. Negative significant correlations (r = −0.890, p < 0.01) and (r = −0....

Impacts of heavy metal concentrations in sediments on the gastropod community structure were assessed in the coastal waters of Dumai, Sumatra, Indonesia. The objective of this study was to relate the levels of heavy metal pollution with the changes of gastropod community structure in the study area. Concentrations of Cd, Cu, Pb, Zn, Ni, and Fe in surface sediments collected from five sampling stations were analyzed and correlated with the abundance, species richness, and diversity of gastropod populations. Sediments at stations with more anthropogenic activities accumulated higher concentrations of heavy metals and consequently displayed lower abundances, lower species richness and diversity; while stations with lower heavy metal concentrations in sediments showed the opposite pattern in gastropod community metrics. The above findings are complemented by significant negative correlations p < 0.05–0.01) between concentrations of Cd, Cu, Pb, Zn, and Ni in the sediments and gastropod abundance and species richness. Among the metals analyzed, Cu and Zn had strongest negative correlations with the gastropod diversity which suggests that these metals may be the most detrimental to gastropod populations in the mangrove area of Dumai coastal waters.

Concentrations of Cd, Cu, Pb, Zn, Ni and Fe were determined in the surface sediments to investigate the distributions, concentrations and the pollution status of heavy metals in Dumai coastal waters. Sediment samples from 23 stations, representing 5 different site groups of eastern, central and western Dumai and southern and northern Rupat Island, were collected in May 2005. The results showed that heavy metal concentrations (in microg/g dry weight; Fe in %) were 0.88 (0.46-1.89); 6.08 (1.61-13.84); 32.34 (14.63-84.90); 53.89 (31.49-87.11); 11.48 (7.26-19.97) and 3.01 (2.10-3.92) for Cd, Cu, Pb, Zn, Ni and Fe, respectively. Generally, metal concentrations in the coastal sediments near Dumai city center (eastern and central Dumai) which have more anthropogenic activities were higher than those at other stations. Average concentration of Cd in the eastern Dumai was slightly higher than effective range low (ERL) but still below effective range medium (ERM) value established by Long et al. (Environmental Management 19(1):81-97, 1995; Environmental Toxicology Chemistry 17(4):714-727, 1997). All other metals were still below ERL and ERM. Calculated enrichment factor (EF), especially for Cd and Pb, and the Pollution load index (PLI) value in the eastern Dumai were also higher than other sites. Cd showed higher EF when compared to other metals. Geo-accumulation indices (I(geo)) in most of the stations (all site groups) were categorized as class 1 (unpolluted to moderately polluted environment) and only Cd in Cargo Port was in class 2 (moderately polluted). Heavy metal concentrations found in the present study were comparable to other regions of the world and based on the calculated indices it can be classified as unpolluted to moderately polluted coastal environment.

In this study, the patterns of the distributions and redistributions of heavy metals in the different soft tissues of Perna viridis were determined. Crystalline style and muscle were found to be sensitive organs to pollution as evidenced by total disturbances in the patterns of metal occurrences. The present findings confirmed the use of different soft tissues as an effective way of monitoring the status of metal pollution in tropical coastal waters. Therefore, the distribution of metals in different parts of P. viridis is proposed as a good indicator of metal pollution in tropical coastal waters.

A total of 40 marine mussel Perna viridis populations collected (2002–2009) from 20 geographical sites located in two busy shipping lanes namely the Straits of Malacca (10 sites; 16 populations) and the Straits of Johore (8 sites; 21 populations) and three populations (2 sites) on the east coast of Peninsular Malaysia, was determined for Cd, Cu, Fe, Ni, Pb and Zn concentrations. In comparison with the maximum permissible limits (MPLs) set by existing food safety guidelines, all metal concentrations found in all the mussel populations were lower than the prescribed MPLs. In terms of the provisional tolerable weekly intake prescribed by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) and oral reference doses (ORDs) by the USEPA, all the studied metals (except for Pb) were unlikely to become the limiting factors or unlikely to pose a risk for the consumption of the mussel populations. The estimated daily intake (EDI) for average level mussel (ALM) and high level mussel (HLM) consumers of mussels was found to be lower than the ORD guidelines for Cd, Cu, Fe, Ni and Zn. Furthermore, the target hazard quotient (THQ) was found to be less than 1 for ALM consumers but higher than 1 for HLM consumers in some sites. Therefore, there were no potential human health risks to the ALM consumers of the mussels. However, for Pb THQ values, the Pb levels in some mussel populations could create a health risk problem. Present results indicate that the consumption amounts of mussels should be limited for minimizing potential health risks of heavy metals to the HLM consumers.

A study was carried out on the distribution and enrichment of trace elements in the core marine sediments of East Malaysia from three stations at South China Sea and one station each at Sulu Sea and Sulawesi Sea. Five stations of sediment cores were recovered and the vertical concentration profiles of six elements namely Br, Cs, Hf, Rb, Ta, and V were determined using the instrumental neutron activation analysis. The enrichment factor, geoaccumulation index and the modified degree of contamination were used to calculate the anthropogenic and pollution status of the elements in the samples. Except for Cs and Hf, which by the enrichment factor are categorized from minimum enrichment to moderate enrichment in all stations and for V and Rb in Sulu Sea and Sulawesi Sea, which are categorized minimum enrichment, other elements are found to be no enrichment at all stations. The geoaccumulation index of Hf in one station shows moderately polluted and for other elements are unpolluted. However, the modified degree values of all samples are less than 1, suggesting very low contamination of elements found in all the stations.

Centella asiatica is a commonly used medicinal plant in Malaysia. As heavy metal accumulation in medicinal plants which are highly consumed by human is a serious issue, thus the assessment of heavy metals in C. asiatica is important for the safety of consumers. In this study, the heavy metal accumulation in C. asiatica and the potential health risks were investigated. Samples of C. asiatica and surface soils were collected from nine different sites around Peninsular Malaysia. The concentration of six heavy metals namely Cd, Cu, Ni, Fe, Pb and Zn were determined by air-acetylene flame atomic absorption spectrophotometer (AAS). The degree of anthropogenic influence was assessed by calculating the enrichment factor (EF) and index of geoaccumulation (Igeo). The heavy metal uptake into the plant was estimated through the calculation of translocation factor (TF), bioconcentration factor (BCF) and correlation study. Estimated daily intakes (EDI) and target hazard quotients (THQ) were used to determine the potential health risk of consuming C. asiatica. The results showed that the overall surface soil was polluted by Cd, Cu and Pb, while the uptake of Zn and Ni by the plants was high. The value of EDI and THQ showed that the potential of Pb toxicity in C. asiatica was high as well. As heavy metal accumulation was confirmed in C. asiatica, daily consumption of the plant derived from polluted sites in Malaysia was not recommended.

Total mercury (Hg) levels in the intertidal surface sediments along the west coast of Peninsular Malaysia were analysed by using heat vaporization method. Total Hg levels in these sediments ranged from 3.00 to 201 µg kg−1 dry weight with a mean concentration of 60.0 µg kg−1 dry weight. More than 90% of the samples studied have the total Hg concentrations less than 150 µg kg−1 dry weight. Compare with the regional data and sediment quality guidelines, the Hg contamination in the intertidal area along the west coast of Peninsular Malaysia was not serious, except for a few sites that might have received anthropogenic Hg in the samples collected between 1999 and 2000. It is suggested that a similar study of heavy metals in the sediments of the west coast of Peninsular Malaysia be conducted regularly.

Samples of mangrove snails Nerita lineata and surface sediments were collected from nine geographical sampling sites in Peninsular Malaysia to determine the concentrations of eight metals. For the soft tissues, the ranges of metal concentrations (μg g(-1) dry weight (dw)) were 3.49-9.02 for As, 0.69-6.25 for Cd, 6.33-25.82 for Cu, 0.71-6.53 for Cr, 221-1285 for Fe, 1.03-50.47 for Pb, and 102.7-130.7 for Zn while Hg as 4.00-64.0 μg kg(-1) dw(-1). For sediments, the ranges were 21.81-59.49 for As, 1.11-2.00 for Cd, 5.59-28.71 for Cu, 18.93-62.91 for Cr, 12973-48916 for Fe, 25.36-172.57 for Pb, and 29.35-130.34 for Zn while for Hg as 2.66-312 μg kg(-1) dw(-1). To determine the ecological risks on the surface habitat sediments, sediment quality guidelines (SQGs), the geochemical indices, and potential ecological risk index (PERI) were used. Based on the SQGs, all the metals investigated were most unlikely to cause any adverse effects. Based on geoaccumulation index and enrichment factor, the sediments were also not polluted by the studied metals. The PERI values based on As, Cd, Cu, Cr, Hg, Pb and Zn in this study were found as 'low ecological risk'. In order to assess the potential health risks, the estimated daily intakes (EDI) of snails were found to be all lower than the RfD guidelines for all metals, except for Pb in some sites investigated. Furthermore, the calculated target hazard quotients (THQ) were found to be less than 1. However, the calculated total target hazard quotients (TTHQ) from all sites were found to be more than 1 for high level consumers except KPPuteh. Therefore, moderate amount of intake is advisable to avoid human health risks to the consumers.

Malaysia is now a developing country and on her way towards being an industrialised one by the year 2020. Most of her industries and urban areas are located on the west coast of Peninsular Malaysia. In addition, the offshore area of the west coast is now one of the busiest shipping lanes in the world. These two phenomena make the intertidal and offshore areas of the west coast of Peninsular Malaysia interesting for scientific studies. Therefore, this study focused on both the offshore and intertidal sediments of the west coast of Peninsular Malaysia. Sampling for sediment samples were done from the northern to the southern ends of the peninsula and these sediment samples were analysed for Cu and Pb. It was found that total Cu concentrations ranged from 0.25 to 13.8 and 0.40 to 315 μg/g dry weight (dw) for offshore and intertidal sediments, respectively. For Pb, it ranged from 3.59 to 25.4 and 0.96 to 69.8 μg/g dw for the offshore and intertidal sediments, respectively. The ranges of Cu and Pb found from the west coast of Peninsular Malaysia were low in comparison to regional data. However, some intertidal areas were identified as receiving anthropogenic Cu and Pb. Geochemical studies revealed that the ‘nonresistant’ fraction for Pb contributed about 70.0% to 75.0% and 54.0% of the total Pb concentration in the offshore and intertidal sediments, respectively. As for Cu, the ‘nonresistant’ fraction contributed about 46.2% to 60.4% and 46.3% of the total Cu concentration in the offshore and intertidal sediments, respectively. The ‘nonresistant’ fraction contained mostly of anthropogenic metals besides natural origins. These ‘nonresistant’ percentages indicated that both the offshore and intertidal areas could have received anthropogenic-derived metals, which could be influenced by physico-chemical properties of the sediments. Although the present data indicated that contamination due to Cu and Pb in the west coast of Peninsular Malaysia especially in the offshore areas were not serious, regular biomonitoring studies along the west coast of Peninsular Malaysia are recommended. Keywords: Cu, Pb, Sediment, Geochemical speciation, West coast of Peninsular Malaysia

Malaysia is one of the fast economic developing nations in the region. From the ecotoxicological points of view, many environmental concerns are expected to continually rise up due to the potential anthropogenic inputs such as industries and urbanization. Although the heavy metal concentrations had been reported in the sediments from the west coast of Peninsular Malaysia, the east coast receives lesser attention since it is not as populous and industrialized as in the west coast. In this study, concentrations of Cu and Zn for surface sediments were determined and the samples were collected between 2002 and 2004, from west (five sites), south (five sites) and east (10 sites) intertidal area of Peninsular Malaysia. Total Cu concentrations ranged from 3.80 to 117 μg/g dry weight with south coast recording the highest mean concentration (38.8 μg/g dry weight), followed by west (31.13 μg/g dry weight) and east coasts (12.96 μg/g dry weight). Total Zn concentrations ranged from 36.6 to 395 μg/g dry weight with west coast recording the highest mean concentration (137 μg/g dry weight), followed by south (111 μg/g dry weight) and east coasts (73.8 μg/g dry weight). Apart from the comparison based on the conventional total concentrations of metals, three geochemical fractions (EFLE, acid-reducible and oxidisable-organic) were also useful in identifying the polluted sites in which the three geochemical fractions in the sediments of the west and south coasts of Peninsular Malaysia had significantly (P < 0.05) higher concentrations of Cu and Zn when compared to those in the east coastal sediments. This had strengthened our previous assumption that the east coast is less polluted by anthropogenic Cu and Zn when compared to the west and south coasts of Peninsular Malaysia.

The concentration of carcinogenic polycyclic aromatic hydrocarbons (c-PAHs) present in the sediment and water of Peninsular Malaysia as well as in the cockle Anadara granosa was investigated. Samples were extracted and analysed with gas chromatography-mass spectrometry. The concentrations of total carcinogenic polycyclic aromatic hydrocarbons (t-PAHs) were measured between 0.80 +/- 0.04 to 162.96 +/- 14.74 ng/g wet weight (ww) in sediment, between 21.85 +/- 2.18 to 76.2 +/- 10.82 ng/L in water samples and between 3.34 +/- 0.77 to 46.85 +/- 5.50 ng/g ww in the cockle tissue. The risk assessment of probable human carcinogens in the Group B2 PAHs was calculated and assessed in accordance with the standards of the United States Environmental Protection Agency (US EPA). Case I in the toxicity assessment analysed the cancer risk to consumers of Malaysian blood cockle. Case II assessed the risk of cancer from exposure to PAHs from multiple pathways. The average cancer risk of case I and case II were found to be classifiable as unsafe according to the US EPA standard. The cancer risk due to c-PAHs acquired by the ingestion of blood cockle was (8.82 +/- 0.54) x 10-6 to (2.67 +/- 0.06) x 10(-2), higher than the US EPA risk management criterion. The non-cancer risks associated with multiple pathways in Kuala Gula, Kuala Juru and Kuala Perlis were higher than the U.S. EPA safe level, but the non-cancer risk for eating blood cockle was below the level of U.S. EPA concern.

Surface sediments were collected from the north western aquatic area (13 intertidal sites and 5 river drainages) of Peninsular Malaysia, which were suspected to have received different anthropogenic sources. These sites included town areas, ports, fishing village, industrial areas, highway sides, jetties and some relatively unpolluted sites. The present study revealed that 4.79–32.91 μg/g dry weight for Cu, 15.85–61.56 μg/g dry weight for Pb, and 33.6–317.4 μg/g dry weight for Zn based on 13 intertidal surface sediments while those based on 5 river drainage surface sediments were 10.24–119.6 μg/g dry weight for Cu, 26.7–125.7 μg/g dry weight for Pb and 88.7–484.1 μg/g dry weight for Zn. In general, the metal levels in the drainage sediments are higher than in the intertidal sediments, suggesting dilution factor in the intertidal sediment and direct effluent from point sources in the drainage sediment. In particular, the total concentrations of Cu, Pb, and Zn for the sampling site at Kuala Kurau Town exceeded the Effect Range Median values for Cu, Pb, and Zn for assessments of sediment quality values for freshwater sediment as proposed by MacDonald et al. (Arch Environ Contam Toxicol 39:20–31, 2000), thus adverse biological effects would be observed above this level. Assessment using enrichment factor (using Fe as a normalizer) and geoaccumulation index showed that the three metals at Kuala Kurau Town and Juru Industry drainage were evidenced as having more enrichment and mostly due to non-natural sources. However, caution should be exercised that the interpretation can only become valid when the ratios, indices, and sediment quality values are combined. This is due to the fact that not all the established indices are applicable and, to a certain extent, some of them should be further revised and improved to suit a different metal for Malaysian sediment. Undoubtedly, sites near drainages at Kuala Kurau Town and Juru River Basin need greater attention to mitigate the heavy metal pollution in the future.

The influential physico-chemical parameters on the spatial and temporal distribution of oligochateas ( Limnodrilus sp.) at the polluted downstream of Langat River were studied in comparison to the unpolluted upstream for 10-months sampling from March 1998 to February 1999. Based on the correlation analysis (CA) and multiple stepwise regression analysis (SRA), the distribution, abundance and density of Limnodrilus sp. were almost consistent during the ten time samplings from April 1998 to February 1999. Based on CA, the density and distribution of Limnodrilus sp. correlated negatively with the pH and dissolved oxygen (DO) while positively correlated with conductivity, biological oxygen demand (BOD), NO 3 , NH 3 , total suspended solids (TSS), chemical oxygen demand (COD) and dissolved concentrations of Cu and Zn. Based on SRA, most of the above parameters are selected as influential factors in affecting the distribution and presence of Limnodrilus sp. on the tropical river. This indicated that the Limnodrilus sp. is a pollutant resistant worm since they can survive in the poor water quality ecosystem. These results based on CA and SRA signified the resistance and tolerance of Limnodrilus sp. survived at the polluted ecosystem of the tropical river. Hence, Limnodrilus sp. is a good bioindicator of polluted rivers in the tropical ecoregion. Journal of Applied Sciences and Environmental Management Vol. 10(3) 2006: 135-140

A study of the impacts of anthropogenic activities on the distribution and biodiversity of benthic macroinvertebrates and water quality of the Langat River (Peninsular Malaysia) was conducted. Four pristine stations from the upstream and 4 stations at the downstream receiving anthropogenic impacts were selected along the river. For 4 consecutive months (March-June 1999), based on the Malaysian DOE (Malaysia Environmental Quality Report 2000, Department of Environment, Ministry of Science, Technology and Environment Malaysia. Maskha Sdn. Bhd. Kuala Lumpur, 86pp; Malaysia Environmental Quality Report 2001, Department of Environment, Ministry of Science, Technology and the Environment Malaysia) water quality index classes, the upstream stations recorded significantly (P