Electronic wastes in sub-Saharan Africa: A critical review of environmental and health impacts, regulatory responses, and future perspectives

Abstract

Recent technological advancements coupled with lax policy regulations have caused increased electronic waste (e-waste) burden in the Sub-Saharan Africa (SSA), thereby exacerbating the environmental signatures of hazardous substances including contaminants of emerging concern (CECs), endocrine-disrupting chemicals (EDCs), persistent organic pollutants (POPs), and toxic metals such as lead (Pb), mercury (Hg), and cadmium (Cd), among others. This review synthesized 62 studies published between 2008 and 2025 to assess the environmental and health risks associated with e-waste disposal in SSA. Pb, Hg, Cd, and brominated flame retardants were the most detected hazardous substances. Near e-waste sites, Pb levels in soil ranged from 120 to 14,000 mg/kg, while Cd reached 6.8 mg/kg in topsoil. Water contamination by Hg near informal processing sites ranged from 0.3 to 2.8 µg/L, exceeding the U.S Centers for Disease Control and Prevention (CDC) safety thresholds. Air pollution from open burning releases polycyclic aromatic hydrocarbons (400–1800 ng/m3), dioxins (3.5–19.2 ng/m3), and volatile metals, worsening the environmental health crisis. Informal recycling practices were the primary source of these pollutants, exposing workers and nearby communities to these toxic substances. This review highlighted significantly elevated health risks, with widespread exceedance of safety thresholds (e.g., blood Pb levels up to 309 µg/dL, compared to CDC reference: 5 µg/dL; Cd up to 8.5 µg/L), leading to cognitive deficits, neurological damage, cancer, and respiratory and reproductive disorders, particularly for the vulnerable populations. Observed trends, gaps in recycling infrastructure and policy underscore the urgent need for improved legislation, formal recycling systems, and public awareness to mitigate health risks in the SSA.