Rapid industrialization in peri-urban centers has accelerated the accumulation of potentially toxic elements (PTEs) in agricultural soils, with implications for food safety and public health concerns. This study quantified PTEs (Cu, Cd, Cr, Pb, and Zn) in soils and yam (Colocasia esculenta) tubers from Kampala’s Luzira Industrial Area. Soil contamination levels were evaluated using the geoaccumulation index (I_geo), contamination factor (CF), and pollution load index (PLI), while soil-to-crop transfer of the PTEs was assessed using the biological accumulation factor (BAF). Statistical analyses (One Way Analysis of Variance, Pearson bivariate correlation, and Principal Component Analysis) were applied to identify relationships among PTEs and sampling sites. Soils exhibited marked industrial influence, with PTE concentrations in the order Zn > Pb > Cu > Cr > Cd. The PLI values above unity confirmed cumulative pollution, with hotspots dominated by Zn, Pb, and Cu. Yam tubers contained lower PTE concentrations but reflected a similar contamination pattern as in the soils. The BAF values were <1 for all the PTEs except Zn, pointing to its greater solubility and mobility in the area’s acidic soils. Health risk assessment indicated that yam consumption was the dominant exposure pathway, with hazard indices (HI) for children exceeding the safe threshold at all industrial sites (HI = 1.14–2.06), and total cancer risks (TCR) ranging from 1.27 × 10⁻⁴ to 5.83 × 10⁻⁴, well above the US EPA limit. For adults, the TCR also surpassed 1 × 10⁻⁴ at sampling points SP3 and SP4. These results found potential transfer of the PTEs from soils into yam tubers, with Cd and Cr being the key drivers of dietary risk.

Contamination of drinking water by potentially toxic elements (PTEs) remains a critical public-health concern in Uganda. This systematic review compiled and harmonized quantitative concentrations (mg/L) for key PTEs, lead (Pb), cadmium (Cd), arsenic (As), chromium (Cr), mercury (Hg), copper (Cu), zinc (Zn), nickel (Ni), cobalt (Co), manganese (Mn), and iron (Fe), across various potable and informal water sources used for drinking, including municipal tap water, boreholes, protected and unprotected springs, wells, rainwater, packaged drinking water, rivers, lakes, and wetlands. A comprehensive search of different databases and key institutional repositories yielded 715 records; after screening and eligibility assessment, 161 studies met the inclusion criteria, and were retained for final synthesis. Reported PTE concentrations frequently exceeded WHO and UNBS drinking water guidelines, with Pb up to 8.2 mg/L, Cd up to 1.4 mg/L, As up to 25.2 mg/L, Cr up to 148 mg/L, Fe up to 67.3 mg/L, and Mn up to 3.75 mg/L, particularly in high-risk zones such as Rwakaiha Wetland, Kasese mining affected catchments, and Kampala’s urban springs and drainage corridors. These hotspots are largely influenced by mining activities, industrial discharges, agricultural runoff, and corrosion of aging water distribution infrastructure, while natural geological conditions contribute to elevated background Fe and Mn in several regions. The review highlights associated health implications, including neurological damage, renal impairment, and cancer risks from chronic exposure, and identifies gaps in regulatory enforcement and routine monitoring. It concludes with practical recommendations, including stricter effluent control, expansion of low-cost adsorption and filtration options at household and community level, and targeted upgrades to water-treatment and distribution systems to promote safe-water access and support Uganda’s progress toward Sustainable Development Goal 6.

Potentially toxic element (PTE) contamination of food systems has emerged as an important environmental and public health concern in many developing countries, including Uganda, owing to rapid urbanization, industrialization, mining activities, wastewater reuse, informal waste disposal, and expanding urban agriculture. This review synthesizes evidence from peer-reviewed and selected grey literature on the occurrence of cadmium (Cd), chromium (Cr), nickel (Ni), lead (Pb), and arsenic (As) in cereals, vegetables, tubers, livestock products, fish, fruits, and processed foods consumed in Uganda. A structured literature synthesis and screening-level dietary risk assessment using estimated daily intake (EDI), target hazard quotient (THQ), hazard index (HI), carcinogenic risk (CR), and total carcinogenic risk (TCR) were conducted to identify contamination hotspots, priority exposure pathways, and potential public health implications. The available evidence revealed substantial spatial variability, with contamination consistently concentrated in mining-influenced agricultural areas, wastewater-irrigated farms, municipal dumpsites, industrial corridors, and urban food markets. Vegetables, cereals, livestock products, fish, and street-vended foods exhibited the greatest contamination burdens, while Pb and Cd were the PTEs most frequently reported exceeding WHO/FAO, Codex Alimentarius, and Ugandan food safety limits. Screening-level risk estimates indicated that Pb, Cd, and Cr contributed most to cumulative dietary exposure, with children consistently exhibiting higher EDI, THQ, HI, and TCR values than adults because of greater food intake relative to body weight. Although cumulative HI and TCR values exceeded recommended screening thresholds in several hotspot regions, these estimates should be interpreted as conservative screening-level indicators derived from heterogeneous published datasets rather than nationally representative measures of dietary exposure. Overall, the evidence indicates that PTE contamination in Ugandan food systems is predominantly hotspot-driven and highlights the need for targeted surveillance, standardized monitoring and reporting, improved pollution control, and strengthened food safety management to reduce chronic dietary exposure and protect public health.