Abstract:
Heavy metals are elements having relatively high density and are toxic at low concentration; they are divided into essential and non-essential heavy metals. They exist naturally within the atmosphere resulting from human and anthropogenic activities. Fish bio-accumulates various heavy metals into their muscles. Heavy metals exist within food chain; man is exposed through consumption of contaminated foods, this result into different health effects such as carcinogenic effects. Heavy metals are determined using various methods such as flame atomic absorption spectrometry. The study aimed at producing baseline data about heavy metals presence, their concentrations in Nile perch samples and water harvested from Lake Kyoga, Kaberamaido district and comparing their concentrations with their respective maximum acceptable limits by W.H.O/F.A.O. Ten Nile perch and water samples were collected randomly once from selected landing sites of Alau and Akapala in Lake Kyoga, Kaberamaido district Uganda. Samples were analyzed at Uganda Industrial Research Institute using Flame atomic absorption spectrometry for heavy metal presence and their concentration. In fish, concentrations ranges of Pb, Cd, and Cr were 0.0–4.858 ppm, 0.308-0.616 ppm and 0.0-0.061 ppm respectively. Ni was not detected in the fish samples. Pb and Cd were higher than their respective recommended limits of 0.2Mg/Kg and 0.05Mg/Kg respectively by F.A.O. Cr was within its recommended limits of 0.1Mg/Kg by F.A.O. In water samples the concentration of Pb was 0.818 ppm and Cr was 0.1190 ppm, these were higher concentration than their maximum acceptable limits of 0.01Mg/Kg and 0.05Mg/Kg respectively by W.H.O. In water, Nickel and cadmium were not detected. Results shown significance between the fish samples collected from the Lake Kyoga landing sites. The reason for the presence of these heavy metals was attributed to pollution of the lake. The study recommended continuous monitoring of heavy metal status in the lake and more studies about heavy metals to be done in other fish species harvested at Lake Kyoga.
