This study examined the concentration of heavy metals in 13 fish species. The results indicated that shellfish species (clams) have the highest metal concentrations, followed by demersal and pelagic fishes. The mean concentration of metals in clams are Zn 88.74 ± 11.98 µg/g, Cu 4.96 ± 1.06 µg/g, Pb 1.22 ± 0.19 µg/g, Cd 0.34 ± 0.04 µg/g dry wt. basis, whereas the same measure in fish tissues was 58.04 ± 18.51, 2.47 ± 1.21, 0.58 ± 0.27 and 0.17 ± 0.08 µg/g dry wt. basis. The concentrations of heavy metals in clams and fish tissues were still lower than the maximum allowable concentrations as suggested by the Malaysian Food Act (1983) and are considered safe for local human consumption.
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.
Livers and muscles of swamp eels (Monopterus albus) were analyzed for bioaccumulation of heavy metals during the plowing stage of a paddy cycle. Results showed heavy metals were bioaccumulated more highly in liver than muscle. Zinc (Zn) was the highest bioaccumulated metal in liver (98.5 ± 8.95 μg/g) and in muscle (48.8 ± 7.17 μg/g). The lowest bioaccumulated metals were cadmium (Cd) in liver (3.44 ± 2.42 μg/g) and copper (Cu) in muscle (0.65 ± 0.20 μg/g). In sediments, Zn was present at the highest mean concentration (52.7 ± 2.85 μg/g), while Cd had the lowest mean concentration (1.04 ± 0.24 μg/g). The biota-sediment accumulation factor (BSAF) for Cu, Zn, Cd and nickel (Ni) in liver tissue was greater than the corresponding BSAF for muscle tissue. For the three plowing stages, metal concentrations were significantly correlated between liver and muscle tissues in all cases, and between sediment and either liver or muscle in most cases. Mean measured metal concentrations in muscle tissue were below the maximum permissible limits established by Malaysian and U.S. governmental agencies, and were therefore regarded as safe for human consumption.
In this study, the ranges of pollutants found in the soft tissues of Perna viridis collected from Kg. Masai and Kg. Sg. Melayu, both located in the Straits of Johore, were 0.85-1.58 μg/g dry weight (dw) for Cd, 5.52-12.2 μg/g dw for Cu, 5.66-8.93 μg/g dw for Ni and 63.4-72.3 μg/g dw for Zn, and 36.4-244 ng/g dry weight for ∑PAHs. Significantly (p < 0.05) higher concentrations of Cd, Cu, Ni, Zn and ∑PAHs in the mussels were found in the water of a seaport site at Kg. Masai than a non-seaport site at Kg. Sg. Melayu population. The ratios of low molecular weight/high molecular weight hydrocarbons (2.94-3.42) and fluoranthene/pyrene (0.43-0.45) in mussels from both sites indicated the origin of the PAHs to be mainly petrogenic. This study has demonstrated the utility of using the soft tissues of P. viridis as a biomonitor of PAH contamination and bioavailability in the coastal waters of Peninsular Malaysia.
Inductively Coupled Argon Plasma Atomic Emission Spectroscopy (ICP-AES) has been used to determine Pb, Zn and Cu levels in 47 exfoliated human teeth (all of which required extraction for orthodontic reasons). Lead concentrations for the group were 1.7 microg (g tooth mass)(-1) to 40.5 microg (g tooth mass)(-1). with a median of 9.8 microg (g tooth mass)(-1). A median lead level in excess of the group value was found for the teeth of six lorry drivers who were included in the study. A more significant enhancement was found for the seven subjects whose age was in excess of 60 years. The median values for Zn and Cu were 123.0 and 0.6 microg (g tooth mass)(-1) respectively. Present values for tooth-Zn are lower than published data for other ethnic groups.