Assessment of contamination, sources and health risks of potentially hazardous elements in surface sediments of Dibang, Cameroon

The assessment of potentially hazardous elements (PHEs) in surface sediments is very important to maintain ecosystem health. The present study examines the contamination levels, ecotoxicological and human health risk patterns of PHEs in surface sediments of Dibang, Cameroon. Sediment samples were analyzed by inductively coupled plasma-mass spectrometry (ICP-MS). The mean content of Cd (0.27), Mn (824.75 mg/kg), Zr (224.33 mg/kg), Pb (116.41 mg/kg) and U (198.86 mg/kg) surpassed upper continental crust values. Cr (27-96 mg/kg) and Pb were also above the sediment quality guidelines values, suggesting toxic stress responses to benthic organisms in the sediment of Dibang. Contamination factor, contamination degree, enrichment factor and geo-accumulation index suggest low to high degree of sediment contamination. Potential ecological risk assessment (PERI: 40.53–161.68) and toxicity indices (TRI/TUs < 5) indicate low potential ecological and toxicity effects. Non-carcinogenic risk assessment values for each hazardous element are less than 1 for children and adults indicating minimal risks to human health. Carcinogenic risk values for Ni, Cr and Pb are lower than the target risk level (1 × 10–4 and 1× 10-6 ); suggesting low carcinogenic health effects. From Pearson correlation coefficient (PCC), principal component analysis (PCA) and hierarchical cluster analysis (HCA) results, Fe, Mn, Zn, Co, V, Ni, Cr and Zr were primarily derived from geogenic sources, while Cu, Cd, Sc, Pb and U originated from both geogenic and anthropogenic sources. Across PCA, HCA and PCC results, the consistent grouping of Cd, Pb, Cu and U suggests a strong anthropogenic signal linked to artisanal mining, fertilizers, industrial and household effluents, agricultural and urban runoff. The integration of multi-index, health risk and multivariate methodologies provides a comprehensive framework for assessing and managing sediment contamination. These findings highlight the urgent need for targeted pollution control, mitigation and environmental management strategies in Dibang, Cameroon.