Heavy metal pollution levels in stream sediments from Bipindi-Kouambo iron deposit, South, Cameroon

Heavy metal pollution in aquatic environments poses a significant hazard due to the persistence of these contaminants. To assess pollution levels and their ecological and community implications, the concentrations of heavy metals in stream sediments were analyzed. Twenty-one stream sediment samples from Bipindi-Kouambo were examined for 14 heavy metals using an Agilent 7700x inductively coupled plasma mass spectrometry system. The average concentrations of metals were found in the following descending order: Iron (Fe) > Manganese (Mn) > Lead (Pb) > Chromium (Cr) > Vanadium (V) > Zinc (Zn) > Nickel (Ni) > Barium (Ba) > Cobalt (Co) > Copper (Cu) > Arsenic (As) > Molybdenum (Mo) > Cadmium (Cd) > Mercury (Hg). To evaluate the degree of pollution, single-element pollution indices were calculated. The geo-accumulation index values for some samples indicated extremely polluted conditions. Mean contamination values suggested moderate to extremely high contamination for As (1 to 3) and for Pb and Fe (>6). The mean enrichment factor values for Cd and Pb exceeded 2, indicating minimal, significant, and extremely high enrichment levels. Similarly, the ecological risk assessment for Pb and Fe indicated moderate to high risk. These results reveal that sediments in Bipindi–Kouambo contain particularly high concentrations of Pb and Fe, which may pose significant risks to both human health and aquatic organisms that depend on these water sources. Key words: Heavy metal pollution, stream sediments, enrichment factor, contamination factor, Bipindi-Kouambo, South Cameroon.