Potentially harmful elements in the geoenvironment: A status review of sources, impacts and regulatory framework in Cameroon, Central Africa

Objectives: Unpolluted environments are vital for human health and well-being. Despite evidence highlighting risks associated with potentially harmful elements (PHEs) in the geoenvironment, systematic assessments in Cameroon remain limited. This review aims to evaluate PHE concentrations in water, soils, and food crops across Cameroon's regions, identify sources, and assess related health risks. Methods: A systematic literature search was conducted using databases such as Google Scholar, Scopus, PubMed, and ScienceDirect. Seventy-seven articles met the inclusion criteria. English-language peer-reviewed studies were selected, and methodological quality was assessed. Health risks were evaluated using the Health Risk Index (HRI), and soil contamination was assessed through the Geo-accumulation Index (Igeo). Key findings: Anthropogenic and geological sources were identified as primary contributors to PHE contamination. Highest PHEs recorded across regions included Fe (446 mg/L, Littoral), Pb (5.68 mg/L, Centre), Al (1.79 mg/L, East), NO₃⁻ (271.83 mg/L, Far North), and F⁻ (334 mg/L, North), in water; Fe (14,635,600 mg/kg, Northeast), Pb (307.2 mg/kg, North), Al (9.84 mg/kg, Littoral), and Cu (15,717 mg/kg, Northwest) in soils; and As (0.51 mg/kg, Northwest), Pb (131 mg/kg, Northwest), Cu (17 mg/kg, West), and Zn (22.5 mg/kg, West) in food crops. The highest Igeo values were observed in soils of the East (0.68–4.33) and Littoral (1.4–13.3) regions. HRIs for vegetable consumption were 2.31, 2.23, and 1.3 for Co, Hg, and Pb, respectively. Conclusions: This review highlights significant health risks from PHE contamination in Cameroon. Implementing robust policies for protecting water, soils, and crops is critical for safeguarding public health.