Organochlorine Residues in Fish and Water Samples from Lake Victoria, Uganda

Abstract

Nile tilapia and Nile perch samples from Lake Victoria were analyzed for lindane (gamma-1,2,3,4,5,6-hexachlorocyclohexane), aldrin (1,2,3,4,10,10-hexachloro-1,4,4a,5,8,8a-hexahydro-1,4:5,8-dimethanonaphthalene), alpha-endosulfan (6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3- benzo(e) dioxathiepin-3-oxide), dieldrin (1,2,3,4,10,10-hexachloro-6,7-epoxy-1,4,4a,5,6,7,8,8a-octahydro-1,4,5,8-dimethanonaphthalene), DDE (p,p'-1,1-dichloro-2,2-bis-(4-chlorophenyl)ethylene), and DDT (p,p'-1,1,1-trichloro-2,2-bis-(4-chlorophenyl)ethane). No significant difference (alpha = 0.05) in the residue levels between fish types for lindane, alpha-endosulfan, p,p'-DDE, p,p'-DDT, and dieldrin was observed. The aldrin levels in Nile perch (Lates niloticus) were significantly higher than the levels in Nile tilapia (Oreochromis niloticus). No difference was observed in the distribution of residues in the different parts of Nile tilapia, although a difference for p,p'-DDE was observed in the Nile perch. No significant difference was observed in the average fat content of the tissue of Nile perch and Nile tilapia; however, the distribution of fat was significantly different in the different parts of the fish, with the abdominal portion having the highest amount of fat. There was no correlation observed in this study between fat content and organochlorine concentration. Lower p,p'-DDT residues levels compared with the p,p'-DDE levels observed in this study indicate that DDT is no longer in use. The levels of organochlorine pesticide residues found in fish samples in this study were below the FAO, U.S. FDA, Australian, and German extraneous residue limits and maximum residue limits. The concentration of organochlorine residues in surface water within the Napoleon Gulf of Lake Victoria was below detection limit (0.1 microg L(-1)).

1,1,1-Trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) and its derivatives in marketed Clarius werneri caught from Ugandas major urban wetlands

“…ΣDDT concentrations of 33 µg/kg in Bagrus docman, 20 µg/kg in Protopterus gethiopinus and 33 µg/kg in Oreochromis niloticus from Lake Edward were reported (Sebugere et al, 2008), on the other hand (Kasozi et al, 2006) found total DDT of 11.67 µg/kg wet wt in Nile perch and 20 µg/kg wet wt in Nile tilapia from Lake Victoria. Similarly, Henry and Kishimba (2006) reported 20 µg/kg wet wt in Nile tilapia from Lake Victoria.…”

“…Although DDT was banned for agricultural and public health purposes in Uganda in the mid 1980's, its derivatives have been detected in sediments (Wasswa, 2009), water (Kasozi et al, 2006) and fish (Bimenya et al, 2007;Kasozi et al, 2006;Kyarimpa, 2007;Ogwok et al, 2009;Sebugere et al, 2008) from various aquatic ecosystems. These derivatives are still slowly being released into aquatic and terrestrial food chains and can reach significant concentrations in animals at higher trophic levels.…”

“…Considering the duration and intensity of the application of DDT in Uganda, the richness of the country in wetlands and the biodiversity in these wetlands, studies on DDT and its derivatives are essential in these systems. Previous studies have collected data on DDT derivatives for various fish species (Bimenya et al, 2007;Kasozi et al, 2006;Kyarimpa, 2007;Sebugere et al, 2008) from different aquatic ecosystems in Uganda. Substantial work has also been carried out on heavy metal contamination in urban wetlands, particularly in Nakivubo (Muwanga, 2006;Nabulo, 2008;Sekabira, 2010).…”

“…Substantial work has also been carried out on heavy metal contamination in urban wetlands, particularly in Nakivubo (Muwanga, 2006;Nabulo, 2008;Sekabira, 2010). Earlier studies on benthic feeders focused on Clarias gariepinus from Lake Edward (Bimenya et al, 2007;Sebugere et al, 2008) and Lake Victoria (Henry and Kishimba, 2006;Kasozi et al, 2006;Kyarimpa, 2007). Nonetheless, there is a lack of data pertaining to DDT derivatives in Clarius werneri from wetland ecosystems.…”

Intoxicação por organoclorados (endosulfan) em bovinos no Uruguai

“…Este composto tem sido detectado em águas destinadas ao consumo humano (Dalvie et al 2003). Tem sido também, detectado em peixes para consumo no Lago Victoria em Uganda, porém em baixas concentrações (Kasozi et al 2006).…”