Polychlorinated biphenyls and hexachlorocyclohexanes in sediments and fish species from the Napoleon Gulf of Lake Victoria, Uganda

Abstract

• High concentrations of PCBs were found at locations near Jinja Municipality.• The PCB and HCH levels were low to moderate compared to other locations worldwide.• The fish from the Napoleon Gulf was fit for consumption in regard to PCBs and HCHs.• The ratios of α-/γ-HCH were low suggesting past input of lindane. a b s t r a c t a r t i c l e i n f o Polychlorinated biphenyls (PCBs) and hexachlorocyclohexanes (HCHs) were analyzed in surface sediments (b30 cm depth) and two fish species: Nile perch (Lates niloticus) and Nile tilapia (Oreochromis niloticus). The samples were collected from the Napoleon Gulf on the northern shore of Lake Victoria. The analysis was done using a gas chromatograph (GC) coupled to a high resolution mass spectrometer for PCBs and a GC equipped with an electron capture detector for HCHs. Total (Σ) PCBs in the muscles of fish varied widely with mean values ranging from 41 to 670 pg g −1 lipid weight (lw). The PCB levels in L. niloticus were significantly greater than those in O. niloticus. The large variability observed in the data was attributed to differences in feeding habits and trophic levels. While O. niloticus is a filter-eating fish species feeding mainly on phytoplankton and zooplankton, L. niloticus have predatory feeding behaviors and prefer a diet of live fish and, therefore, are more prone to bioaccumulate contaminants. The mean PCB concentrations in the sediments varied from 362 to 848 pg g −1 dry weight. Variations in PCB levels were observed from one study site to another, this was attributed to the nature and particle size of the sediments. HCH isomers were detected in fish at mean concentrations of up to 45,900 pg g −1 lw. The PCB and HCH concentrations were lower than those from previous studies elsewhere in literature and were below the maximum residue limits set by the European Commission and FAO/WHO Codex Alimentarius Commission, implying that the fish was fit for human consumption.

Polychlorinated biphenyls in sediments and fish species from the Murchison Bay of Lake Victoria, Uganda

“…Average concentrations of the Σ 18 PCBs ranged from 80 to 779 pg g − 1 wet weight (ww). The concentrations were in the same range as those reported in similar fish species from the Napoleon Gulf of Lake Victoria (94-716 pg g −1 ww: Ssebugere et al, 2013a;Ssebugere et al, 2014) These levels were at least an order of magnitude higher compared to the present results. In Egypt, Said et al (2008) reported PCB concentrations varying from 3320 to 72 060 pg g −1 lw in fish (O. niloticus and Clarias gariepinus) from Lake Burullus.…”

“…They were 3-fold higher than those reported in sediments from the Napoleon Gulf and Thurston Bay of Lake Victoria (Ssebugere et al, 2013b;Ssebugere et al, 2014). The PCB concentrations in the present study were comparable to data from other fresh water bodies in Africa: the Nile River in Egypt (El-Kady et al, 2007), Ghar El Melh lagoon in Tunisia (Ameur et al, 2011), Pangani River basin in Tanzania (Hellar-Kihampa et al, 2013) and Congo River basin in the Democratic Republic of Congo (Verhaert et al, 2013).…”

“…To our knowledge whereas PCBs have been reported in fish and sediments from the Napoleon Gulf and Thurston Bay of Lake Victoria (Ssebugere et al, 2013a, b;Ssebugere et al, 2014) and from other water bodies in the world (Manirakiza et al, 2002;Adu-Kumi et al, 2010;Darko et al, 2008;Helm et al, 2008;Eqani et al, 2013;Verhaert et al, 2013), literature shows no work about these pollutants in the Murchison Bay. The Bay is a major hotspot for discharge of industrial outflow, urban runoff and municipal effluents from Kampala, Uganda's capital city (Banadda et al, 2009).…”

“…These developments coupled with a population of over one million people in its catchment area have resulted in increased pollution (Banadda et al, 2009(Banadda et al, , 2011a(Banadda et al, , 2011bWasswa et al, 2010). Polychlorinated biphenyls (PCBs) have previously been documented in the lake (Ssebugere et al 2013a, b;Ssebugere et al, 2014). The PCBs are released into the environment as a result of industrial applications such as capacitors, hydraulic fluids in electronic equipment, and coolants and lubricants in transformers (Gidarakos et al, 2009;Moon et al, 2012;Lundin et al, 2013;Miller et al, 2013).…”

Particle size distributions and gas–particle partitioning of polychlorinated dibenzo-p-dioxins and dibenzofurans in ambient air during haze days and normal days

“…The Shapiro-Wilk test was used for verifying the normality of data. Since concentration values were not normally distributed, the Mann-Whitney U test was used for comparing two data sets (Ssebugere et al, 2014a;Ssebugere et al, 2014b). The comparisons of particle and PCDD/F concentrations during normal days and haze days were tested using this method.…”