Perspective of heavy metal potential risk in wetland soil and fish for amplified waste management around Lake Victoria, Uganda

Abstract

Ssanyu GA, Kiwanuka M, Lunkuse I, Okumu D, Mbeiza NM. 2023. Perspective of heavy metal potential risk in wetlands soil and fish for amplified waste management around Lake Victoria, Uganda. Lake Reserv Manage. X:XXX–XXX. Increasing unsustainable agricultural and land management activities reduce the effectiveness of wetlands in absorbing heavy metals. This leads to high and detectable heavy metal levels in wetland soil and fish, respectively. This study assessed the content of heavy metals, particularly cadmium (Cd), chromium (Cr), cobalt (Co), lead (Pb), and nickel (Ni), in the water, soils, and commercial wetland fishes (Protopterus aethiopicus and Clarias galiepinus) from Lake Victoria wetlands with different land uses. Heavy metal analysis was done using inductively coupled plasma–optical emission spectrometry. Mean Cd and Pb levels were below the World Health Organization (WHO) permissible limits in all the wetlands’ water samples. Wetlands associated with urban or industrial development presented higher levels of Pb than other wetlands. Wairaka wetland, associated with commercial agriculture, presented a significantly higher mean concentration of Cr (191.2 mg/kg) in the soil than other wetlands. Cr and Ni contents were high in all fish muscle samples, while Cd and Pb contents in fish muscles were below WHO permissible limits, except for Clarias fish from 2 urban/industrial and one commercial agriculture affected wetlands, which had higher Pb than in other fish muscle tissues. The hazard index values of both fish species were greater than one from urban/industrial and commercial agriculture associated wetlands, implying that fish consumers would encounter noncarcinogenic health risks. More efforts are needed to strengthen Lake Victoria industrial and municipal waste management strategies to reduce the potential heavy metal risk in wetland soil and fish.