An Assessment Of Metal Distribution And Metal Soluble Fractions In The Edible Molluscs From Malaysia

The present study focused on the heavy metal concentrations in the different parts of 12 species of Malaysian molluscs, six species of bivalves and gastropods, respectively. The aim of the present study was to provide information on the concentrations of the essential metals: Cu, Fe and Zn and the non-essential metals: Cd, Ni and Pb in the edible tissues of molluscs with particular reference to the food safety and ecotoxicological points of views. For bivalves, Cu, Fe and Zn concentrations in the edible parts ranged at 1.80-79.8 μg/g dw, 42.9-4895 μg/g dw and 28.3-379 μg/g dw, respectively. While for Cd, Pb and Ni, they ranged at 0.253-22.4 μg/g dw, 0.558-46.5 μg/g dw and 0.656-23.6 μg/g dw, respectively. As for gastropods, Cu, Fe and Zn concentrations in the edible parts ranged at 1.97-686 μg/g dw, 51.2-2921 μg/g dw, 22.8-337 μg/g dw, respectively. While for Cd, Pb and Ni, they ranged at 0.159-32.9 μg/g dw, 1.20-43.0 μg/g dw and 0.222-27.9 μg/g dw, respectively. The study on the soluble and insoluble heavy metal fractions revealed that an abundance of soluble metals like Cd, Pb and Ni were consistently found in some tissues of the molluscs such as in the foot, mantle and muscle and they could potentially be transferred through the food web (predators). The total metal concentrations in the different parts were compared with the food permissible limits set by six organizations around the world. However, to overcome the overestimation of food safety based on the total metal concentrations in the different edible tissues, determination of the metal soluble fractions in the tissues were further investigated in this study. The soluble concentrations were compared with the permissible limits set by the Environmental health Criteria (1998, 2001) and the FAO/WHO (1984). From the present findings, it was found that consumption of large amounts of Per. viridis, G. expansa and most of the gastropods could pose metal toxic to their consumer. The elevated of Cu and Zn concentrations in most of the edible parts of the gastropods suggested that the consumption of large amounts of most gastropods were not advisable. As for Cd levels, it was found that the byssus of Per. viridis and D. faba; and the digestive gland and mantle of Chi. capucinus were not safe for continuous consumption (for example: more than a week) since the levels would exceed the permissible limit. Besides, the continuous consumption of the byssus of Per. viridis and D. faba would also potentially cause Pb toxicity. The information on the metal distributions in the different parts obtained by using the cluster analysis is important to facilitate the biomonitoring of the marine environment, which based on the use of different tissues in the species of molluscs of Malaysi

Heavy metal concentrations in the different tissues of Chicoreus capucinus : the significance as a biomonitor.

The present study aims at to determine the concentrations of Cu, Fe, Ni, Pb and Zn in the different parts of Chicoreus capucinus of Janggut River. Generally, it was found that the different soft tissues accumulated higher concentrations of essential Cu, Fe and Zn. In particular, the snail digestive caecum was highly accumulative of Cu while the snail’s digestive tract (glands, caecum and intestines) was also highly accumulatively of Zn. The snail’s operculum was highly accumulative of Fe. As for the shell, it was highly accumulative of nonessential Ni and Pb. Different levels of metals in the different tissues of C. capucinusindicated the metal regulation in the different tissues are different due to difference in metallothionein binding sites. Therefore, it was suggested that C. capucinuscould be a new biomonitor to monitor heavy metal bioavailabilities and contamination in the Malaysian intertidal area as recommended by the Mussel Watch Program

The Different Capability Of Metal Uptake In The Shell Of Perna Viridis Compared To The Different Soft Tissues: A Statistical Approach

Distribution of metals in bivalves is usually examined based on different metal concentrations in the different tissues of the bivalves. Patterns of metal distribution between the shells and the different soft tissues of two geographical populations of the green-lipped mussel Perna viridis were investigated. The correlation analysis showed insignificant correlation between the shells and the different soft tissues. The multiple linear stepwise regression analysis showed that the shells were not influential in metal accumulation in the total soft tissues. The cluster analysis showed that the shells were clustered differently, as a single entity, from the rest of the different soft tissues. All these findings indicate that the capability of metal uptake by the shell of Perna viridis differs

Distribution of heavy metals concentrations in the different parts of the clam Polymesoda erosa: The potentials as a biomonitor.

The bivalve Polymesoda erosa were collected from Sepang Kecil River (Selangor), Parit Jawa (Batu Pahat) and Telok Mas (Malacca), located in the west coast of Peninsular Malaysia. The soft tissues of the clams were dissected into five parts: muscle, foot, mantle, gill and remaining soft tissues. The shells and the pooled dissected tissues were determined for heavy metal concentrations. It was found that gill accumulated the highest Cu followed by remaining soft tissues and mantle for all the three sites. Meanwhile, shell was found to accumulate the non-essential metals like Cd, Pb and Ni. For Zn, highest concentrations were found in the mantle and gill. On the other hand, there were no clear pattern was observed in the accumulation of Fe for all the six tissues. Different levels of metals in the different soft tissues of P. erosa indicated that the metal regulation in those tissues are different due to differences in binding sites at the metallothionein. Therefore, P. erosa can be a potential biomonitor of heavy metal bioavailability and contamination, as recommended by the Mussel Watch Program

Heavy metal concentrations (CD, CU, NI, PB, FE AND ZN)in the different soft tissues and shells of pholas orientalis collected from Sekinchan and Pantai Remis, Selangor.

The clam, Pholas orientaliswere collected from the mudflats of Sekinchan and Pantai Remis, and their soft tissues were dissected into crystalline style, siphon, mantle and foot; while the shells were divided into three parts namely the umbo, smooth part (anterior of shell) and rough part (posterior of shell). Generally, the results show that: 1) All the different soft tissues accumulated higher concentrations of essential Cu, Zn and Fe when compared to those in the hard tissues; 2) On the other hand, the three hard tissues accumulated higher concentrations of nonessential Cd, Ni and Pb than those in the soft tissues. These results reflected a different binding affinity for the two different metal groups between the soft and the hard tissues; 3) The different levels of metals found within the four different tissues indicated that metal detoxification mechanism in the different organs are not similar in P. orientalis. The ecological distribution and metal distribution in the different tissues of P. orientaliscan serve as a baseline for future reference

Is a mussel processing site a point source of Zn contamination? evidence of Zn remobilization from boiled mussel, Perna viridis

Sediment sampling in the Straits of Johore revealed that the surface sediments collected at a jetty near a mussel processing factory in Kg. Sg. Melayu had elevated Zn concentration in its first geochemical fraction; namely, easily, freely, leachable or exchangeable (EFLE) and its total concentration. This total Zn level in the sediment was comparable to the polluted sites on the west coast of Peninsular Malaysia. It was assumed that the tap water, in which mussels had been boiled, might have contained high levels of Zn which would then be released to the drainage system and finally emptied into the coastal waters where the jetty is located. In order to confirm this point source of Zn contamination, a laboratory study was designed to ascertain if the boiled mussels contained higher concentrations of metals compared to a control group. The laboratory results showed that distilled water, in which fresh mussel tissues had been boiled for 15 minutes, possessed significantly (P < 0.05) higher levels of dissolved Zn. In addition, Zn concentrations in the total boiled soft tissues and boiled shells of fresh mussel Perna viridis were significantly (P < 0.05) lower than the Zn levels before boiling, and this finding evidently showed that Zn in the mussel tissues was remobilized and thus released to the water. Therefore, these results supported the conclusion that the mussel processing factory at Kg. Sg. Melayu, which used tap water to boil the mussels before shucking, was a point source of Zn contamination in this area in the Straits of Johore

Determination of Heavy Metal Distributions in the Green-Lipped Mussel Perna viridis as Bioindicators of Heavy Metal Contamination in the Johore Straits and Senggarang, Peninsular Malaysia.

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

The length of the crystalline style of Perna viridis in relation to shell length, shell width and shell height : data for future reference.

The crystalline style (CS) is a gelatinous rod-like body that contains starch-digesting enzymes in the hemolymph of the bivalves. The lengths of the CS, shell lengths, shell widths and shell heights of the green-lipped mussel Perna viridis, collected from seven sampling sites in southern coastal waters of Peninsular Malaysia, were measured. The lengths of CS in relation to shell length, shell width and shell height were 72-73%, 211-218% and 154-157%, respectively. The correlation analysis indicated that the length of CS is positively and significantly (P< 0.001) correlated to the shell length (R= 0.81), shell width (R= 0.82) and shell height (R= 0.64). The percentages of the CS length to the shell parameters could be potentially used to identify the different mussel species since different mussel species have a specific CS length to the shell length. The present findings can serve as an important reference for comparative purpose with other bivalve species

Heavy metal concentrations(CU, PB, NI AND ZN)in the surface sediments from a semi-enclosed intertidal water, the Johore Straits : monitoring data for future reference.

Since decades ago, the 1909-built dam-like Johore Causeway has been of much environmental concerns. This is due to the rapid economic and industrial development in the southern Johore of West Malaysia and Singapore which created a lot of anthropogenic pollutants into this semi-enclosed intertidal ecosystem via riverine inputs. In this study, surface sediments were collected from the western and eastern parts of the Johore Straits, in August 2004. The samples were analyzed for Cu, Zn, Pb and Ni. As a function of dry weight, the mean total concentrations of these metals were 28.6 μg/g (west) and 110 μg/g (east) for Cu; 137 μg/g (west) and 180 μg/g (east) for Zn; 33.7 μg/g (west) and 33.6 μg/g (east) for Pb and 22.6 μg/g (west) and 27.3 μg/g (east) for Ni. Geochemical studies revealed that the metal nonresistant fractions of the sediments were 52.3%, 67.3%, 29.2% and 64.9% for Cu, Zn, Pb and Ni, respectively. The non-resistant percentages indicated that the Johore Straits is receiving anthropogenic Zn, Ni, Cu and Pb. The present data indicated that some sites at the Straits were polluted with heavy metals to a certain degree based on the set Sediment Quality Guidelines/Criteria for the similar metals. The data found in this study should provide useful reference if the dam-like Causeway were to be replaced by a proposed free-flow bridge in the future

A preliminary study on the use of gastropod-sediment accumulation factors (GSAFs) to identify gastropods as potential biomonitors of heavy metals contamination.

This study presented the gastropod-sediment accumulation factor (GSAF) of four species of tropical gastropods from Peninsular Malaysia, which focused on the different parts of gastropods namely shell, digestive caecum, operculum and foot. It was found that the different parts of the gastropods could be classified into 1) macroconcentrator (GSAF > 2), 2) microconcentrator (1 < GSAF <2) and 3) deconcentrators (GSAF < 1), as proposed by Dallinger (1993). It was found that Chicoreous capucinus and Pomacea insularum were good macroconcentrators for Pb (in all parts namely shell, digestive caecum, operculum and foot). Thais sp. was found as a good macroconcentrator for Cu in all parts while Chi. capucinus was a good macroconcentrator for Cd and Cu based on shell, digestive caecum and foot and for Zn based on digestive caecum, operculum and foot. Similarly Cerithidea obtusa was found as a good macroconcentrator for Cd based on shell, digestive caecum and operculum. Therefore, the above results indicated that the metal accumulation rates and metal storage were tissue specific, and thus specific organ/tissues can be used for a better interpretative biomonitoring purpose. This preliminary study points to the use of GSAF values as potential indicators of metal bioavailabilities and contamination in coastal areas of Peninsular Malaysia and this should merit further studies