Health Risk Assessment of Potentially Toxic Elements Contamination of Commonly Consumed Fruits in Bahir Dar Town, Northwest Ethiopia

Overview

This study measured Pb, Cd, Cr, and Cu concentrations in the edible portions of mango, banana, and orange collected from open markets in Bahir Dar town, Northwest Ethiopia, and assessed associated noncarcinogenic and carcinogenic health risks. Mango showed Pb (0.576 mg/kg dw) and Cd (1.771 mg/kg dw) concentrations exceeding FAO/WHO permissible limits of 0.3 and 0.2 mg/kg respectively, yielding a hazard index of 3.69 and a target cancer risk of 1.71 × 10⁻³, which exceeds the moderate risk threshold. Banana and orange Pb was not detected, with Cd below FAO/WHO limits.

Key numbers

Concentrations in edible portions (mg/kg dry weight, n = 9 per fruit, from composite of 40 samples each):

FAO/WHO limits (mg/kg): Pb 0.3, Cd 0.2, Cr 2.3, Cu 40.

Hazard Index (HI): Mango 3.69 (exceeds 1.0 threshold); Banana 0.02; Orange 0.02.

Target Cancer Risk (TCR): Mango 1.71 × 10⁻³ (above moderate risk limit of >1 × 10⁻³); Banana 7.16 × 10⁻⁴; Orange 7.15 × 10⁻⁴ (all above US-EPA safe limit of <1 × 10⁻⁶).

Ingestion rate used: 115 g person⁻¹ day⁻¹ (Ethiopian adult); reference body weight 70 kg.

Methods

Analytical method: Flame atomic absorption spectrophotometry (FAAS), Buck Scientific Model 210VGP, at University of Gondar. Wet acid digestion with HNO₃/HClO₄/H₂O₂ triacid mixture at 240°C. All values reported in dry weight. Method detection limits: Pb 0.082, Cr 0.051, Cd 0.020, Cu 0.009 mg/L. Recovery: 90.8–107%. No speciation performed; total metal concentrations only (note: Cr is total Cr, not Cr-VI). Study period January–June 2021.

Implications

Certification: Mango from Ethiopia or comparable tropical markets with irrigated agricultural practices carries documented Pb and Cd contamination risk. Cd in mango at 1.771 mg/kg dw is approximately 8× the FAO/WHO limit. These values are not wet-weight and should be converted using moisture content before comparison with most regulatory limits (which are expressed on a fresh weight basis).

Courses: Illustrates that fruit contamination in developing markets can exceed limits, particularly where industrial and agricultural Cd/Pb inputs affect soil. Useful contrast with North American/European occurrence data.

App: Mango from Ethiopia flagged; broadly suggests mango as a commodity with regional contamination variance. Data gap for fresh-weight conversion factor in this source.

Wiki pages updated on ingest

• Mango
• Banana
• orange
• Lead
• Cadmium

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