Kasozi et al. 2021 — Heavy metal contamination in beef from Eastern Uganda with health risk assessment
This study measured concentrations of Cu, Zn, Pb, Cd, Co, Fe, Ni, and Cr in 40 raw beef samples collected from butcher points of sale in Soroti district, Eastern Uganda, and assessed health risks via target hazard quotient (THQ) and incremental lifetime cancer risk (ILCR) modeling. Analysis by atomic absorption spectrophotometry (PerkinElmer AAS 2380). Mean concentrations (ppm): Cu 1.45, Zn 44.43, Pb 5.42, Cd 0.41, Co 1.63, Fe 164.33, Ni 14.96, Cr 19.37. Of the measured non-essential metals, only Cd was below the WHO guideline limit (0.5 ppm). Lead (mean 5.42 ppm; max 10.94 ppm), Ni (mean 14.96 ppm), and Cr (mean 19.37 ppm) substantially exceeded WHO limits. THQ values above 1 for most metals indicated non-carcinogenic health risk in both adults and children. Cancer risk from Ni and Cr was notably elevated, especially for children.
Key numbers
n=40 beef samples (Soroti district, Eastern Uganda). Method: AAS (PerkinElmer 2380). Mean concentrations (ppm wet weight): Pb 5.42 (range 2.41-10.94); Cd 0.41 (range 0.11-0.98); Ni 14.96 (range 5.97-26.58); Cr 19.37 (range 6.94-35.89); Cu 1.45; Zn 44.43; Co 1.63; Fe 164.33. WHO limits (ppm): Pb 0.1; Cd 0.5; Ni 1.0; Cr 0.05. THQ greater than 1 for Pb, Ni, Cr, Cu, Co, Fe (non-carcinogenic risk flagged). Cancer risk: Ni > Cr > Cd > Pb; children > adults. Collection period: December 2019 - March 2020.
Methods (brief)
Observational study; 40 beef samples collected from rural butcheries in Soroti. AAS analysis at wavelengths specific to each metal. Health risk modeled using: EDI (estimated daily intake at Uganda-specific ingestion rates 120 g/day adults, 56.7 g/day children; BW 60.7 and 20.5 kg), THQ (non-carcinogenic), ILCR (carcinogenic) per US EPA methodology. Limitation: single-region, single-season cross-sectional sample; potential for contamination during slaughter and butchering not controlled.
Implications
Certification: Eastern Uganda beef shows substantially elevated Pb, Ni, and Cr relative to WHO guidelines; Cd is the only measured non-essential metal within acceptable limits. Courses: Illustrates how livestock raised in environmentally contaminated peri-urban and industrial areas can accumulate heavy metals in muscle tissue at levels exceeding food safety benchmarks. App: Beef from sub-Saharan Africa sourced from regions near tanneries and metal-working industries carries elevated Ni and Cr risk; geographic sourcing matters for risk estimation.