Plant nutrition and health effects of vegetables grown on contaminated soils – lessons from Sub Saharan Africa: a review

Soils in sub-Saharan Africa (SSA) are central to both agricultural productivity and human nutrition, yet increasing contamination from mining activities, wastewater irrigation, and agrochemical inputs has intensified the accumulation of toxic trace elements in food crops. This review synthesizes current evidence on the soil–plant–human transfer of toxic elements alongside essential nutrients, highlighting the inherent trade-offs between food safety and nutrition security in SSA. Drawing on interdisciplinary literature, the review examines the mechanisms governing metal bioavailability in soils, plant uptake dynamics, and dietary exposure pathways, with particular emphasis on leafy vegetables as key nutrient sources and major vectors of contaminant intake. While various mitigation strategies including soil amendments, phytoremediation, and soilless cultivation have shown technical effectiveness in reducing metal uptake, their real-world implementation remains limited by economic constraints, infrastructure deficits, and weak regulatory systems. The review identifies a critical gap in the application of integrated risk–benefit frameworks that simultaneously evaluate contaminant exposure and nutritional value, which is essential for informed decision-making in resource-constrained settings. It further highlights significant data limitations regarding bioavailability, crop-specific accumulation patterns, and population-level dietary exposure across SSA. By bridging soil science, agronomy, and public health perspectives, this review advances a more holistic understanding of contamination risks within food systems. It concludes by emphasizing the need for context-specific, scalable interventions and coordinated policy, research, and extension efforts to safeguard both human health and nutrition security in contaminated agricultural environments. Addressing these challenges is essential for protecting public health while sustaining nutrition security in mining-affected regions of SSA.