Selected Heavy Metals in Water and Bottom Sediments in Lake Turkana, Kenya: Distribution and Statistical Analysis

Purpose: Heavy metal pollution in aquatic ecosystems is a threat to health, safe water and food security. Therefore, the study aimed at investigating the quality of Lake Turkana’s ecosystem by analyzing levels of lead, cadmium and chromium in water and bottom sediments for necessary interventions. Methodology: During the dry season, field sampling of water and bottom sediments was performed randomly in triplicates from five locations of Lake Turkana mapped out based on adjacency to potential anthropogenic point pollution sources. Levels of selected heavy metals (lead, cadmium and chromium) were determined using flame atomic absorption spectroscopy (iCE3300 AA System) at Kenyatta University’s food science laboratories. Findings: Water lead, cadmium and chromium ranged: 0.11±0.01 to 0.12±0.00 mg/L, 0.00±0.00 to 0.03±0.00 mg/L and 0.01±0.00 to 0.03±0.01mg/L, respectively while sediment lead, cadmium and chromium ranged: 0.56±0.11 to 1.01±0.03 mg/Kg, 0.02±0.00 to 0.24±0.10 mg/Kg and 0.11±0.03 to 0.20±0.05 mg/Kg, respectively. The lake water contained lead and cadmium beyond WHO allowable limits while sediment lead, cadmium and chromium levels complied with USEPA standards. Lead, cadmium and chromium levels in sediments were significantly higher (p < 0.05) than in water in 100 %, 80 % and 60 % of the sites, respectively. Unique Contribution to Theory, Policy and Practice: The study findings necessitate concerted efforts by researchers, community and policy makers to monitor and control heavy metal levels to ensure water and sediment quality is maintained.