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Title:	Heavy metals concentration in Tilapia (oreochromis niloticus) from selected sites in Selangor and health risks estimation
Authors:	Taweel Abdulali Khalifa Ali (P46959)
Supervisor:	Mohammad Shuhaimi-Othman, Assoc. Prof. Dr.
Keywords:	Heavy metals- Environmental aspects
Issue Date:	28-Aug-2014
Description:	The accumulation of heavy metals in fish has been extensively studied. However, research has basically focused on the fish edible tissue (muscle), whereas distribution patterns among other tissues, such as livers and gills have been mostly neglected. The present study has been undertaken to determine the levels of some essential heavy metals, including copper (Cu), zinc (Zn), iron (Fe), manganese (Mn), cobalt (Co) and chromium (Cr) and some non-essential heavy metals including aluminium (Al), arsenic (As), cadmium (Cd), lead (Pb), and nickel (Ni) in livers, gill and muscle of freshwater tilapia fish (Oreochromis niloticus). The fish were sampled from sites in Selangor, Peninsular Malaysia throughout a year between April, 2009 and February, 2010. The studied sites are Serdang Night Market, Bandar Baru Bangi Night Market, Kajang Wet Market, Bandar Baru Bangi Wet Market, Culture Pond A, Culture Pond B, Langat River, Cempaka Lake and Engineering Lake as well as one site in Libya named Ain Kiaam Lake for comparison purposes of heavy metals concentration between both countries. Heavy metal concentrations were detected using an inductively coupled plasma spectrometer (ICP-MS) after microwave-acid digestion. The results revealed that heavy metals concentration levels varied at all the sampling stations and the livers appeared to be the main heavy metal storage tissue. Heavy metal concentrations were relatively high in livers compared to the gills and muscle in all studied sites. Samples collected from Ain Kiaam (Libya) recorded relatively lower heavy metal concentrations than those collected from all other sites in Malaysia. Periodic levels of the metals were also different at the sampling sites (ANOVA, P<0.05). Variations in sampling sites were noted in the level of heavy metals in tilapia, generally the highest level was recorded in tilapia from natural sites (Langat River, Cempaka Lake and Engineering Lake). Based on the results, heavy metal concentration levels in tilapia fish muscle in all studied sites were lower than the maximum permissible limit as recommended by international and national standards for food and human health. The Hazard Quotient (HQ) values in fish from all sites, were not exceeded the safe limit of 1.00, which indicates that fishes from this study sites is safe to be eaten. Thus, muscle tissue of tilapia from all sites may not cause any serious health risk. The maximum allowable fish consumption rate (kg/day) was calculated and the lowest rate was recorded in fish from Cempaka Lake for As with 0.533 kg/day followed by Culture Pond B with 0.619 kg/day. Acute toxicity tests of Cu, Cd, Zn and Pb on tilapia fish fingerlings in the laboratory were also carried out to determine the LC50s. The LC50 increased with the decrease in mean exposure times. The LC50s for 96 hours for Cu, Cd, Zn and Pb were 1093, 3751, 16177 and 1494 μg/L respectively. The toxicity ranking of the four heavy metals was Cu > Pb > Cd > Zn.,Ph.D
Pages:	271
Call Number:	TD196.M4 T348 2015
Publisher:	UKM, Kuala Lumpur
Appears in Collections:	Faculty of Health Sciences / Fakulti Sains Kesihatan

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