Review Finds Lead and Cadmium Exceed Safe Limits in Ethiopian Foods

A systematic review of 23 studies published between 2000 and February 2026 has concluded that heavy-metal contamination of food in Ethiopia is widespread and uneven, with lead, cadmium and chromium repeatedly exceeding international safety limits in vegetables, cereals and fish, particularly in industrial, urban and intensively farmed areas. The review, published in the journal Food Safety and Risk, synthesizes quantitative concentration data from across the country’s food supply and compares them against FAO/WHO maximum permissible limits, offering the most integrated picture to date of dietary heavy-metal exposure risks in Ethiopia.

The analysis, which followed PRISMA reporting principles, identified 51 records through searches of PubMed, Scopus, Web of Science, Google Scholar, Science Direct and institutional repositories. After removing 12 duplicates and screening 39 records at title and abstract stage, 16 were excluded for failing eligibility criteria, leaving 23 studies that all reported quantitative heavy-metal concentrations in edible products using recognized analytical methods. Studies focused solely on soil, water or sediment, lacked quantitative data, or provided insufficient methodological detail were excluded. The included work spanned cereals, vegetables, fruits, milk, meat and fish from multiple regions.

According to the review’s summary figure, lead was the most frequently reported contaminant exceeding FAO/WHO limits, appearing in exceedance in roughly 65 to 70 percent of the studies, followed by cadmium and chromium. Fish and vegetables emerged as the most vulnerable food groups. Copper levels were mostly within permissible limits, and mercury concentrations in fish were consistently below the maximum limit of 0.5 mg/kg. Nickel, cobalt and palladium are not strictly regulated in foods by FAO/WHO, but the review notes that elevated values, especially in fruits, vegetables and fish, may pose additional concerns.

The regional pattern is striking. Cereals including teff, wheat, barley and maize sold at Deberemarkose market showed chromium between 1.57 and 2.22 mg/kg, copper from 1.28 up to 294 mg/kg, lead from 0.34 to 0.52 mg/kg, and cadmium between 1.84 and 2.01 mg/kg. Against the FAO/WHO vegetable and cereal limits cited in the review — lead at or below 0.3 mg/kg and cadmium at or below 0.2 mg/kg — the cadmium values represent a many-fold exceedance. The review flags the extraordinary copper value of 294 mg/kg as possibly indicating local contamination or an analytical error, since copper elsewhere remained below the 40 mg/kg ceiling.

Vegetables from industrial and urban hotspots fared poorly. In Dukem, tomato, cabbage and lettuce carried chromium of 2.9 to 3.77 mg/kg, cadmium of 2.2 to 3.68 mg/kg and lead of 4.6 to 5.5 mg/kg. Sebeta vegetables, including lettuce, cabbage and red beet, contained lead of 5.87 to 7.67 mg/kg and nickel of 20.67 to 23.59 mg/kg, while Mojo tomatoes and cabbage showed lead of 3.63 to 7.56 mg/kg. Vegetables from Akaki, Kera and Debre Birhan reached lead concentrations as high as 12.3 mg/kg and chromium up to 8.8 mg/kg. By contrast, chromium in most vegetable samples elsewhere fell within the 2.3 mg/kg guideline, and copper remained well under its 40 mg/kg limit.

Fruit results were more heterogeneous. Avocado, mango, papaya, pineapple, banana and orange from Addis Ababa and Hawasa markets contained copper of 0.13 to 3.13 mg/kg and lead of 0.07 to 0.37 mg/kg, generally acceptable levels. Watermelon from the Somali region also fell below limits. But avocado, banana, papaya and mango from Arbaminch showed copper of 21.3 to 32.6 mg/kg, lead of 13.8 to 27 mg/kg, chromium of 9.5 to 29 mg/kg and cobalt of 14.8 to 28.3 mg/kg — lead and chromium values that far exceed the fruit limits of 0.1 and 0.05 mg/kg respectively. Mangoes from Arbaminch, Wolita Sodo and Demote Gale in a separate study showed very low lead and copper, underscoring how sharply contamination can vary within a single commodity and even a single town.

Animal-derived foods showed a similar location-dependent split. Raw milk from the Hawasa Industrial Zone contained copper of 63.0 to 77.78 mg/kg — far above the 30 mg/kg limit for milk and meat — along with chromium of 2.0 to 3.29 mg/kg and nickel of 1.0 to 2.93 mg/kg, which the review attributes to potential contamination from industrial effluents or feed sources. Milk from Bahir Dar showed chromium of just 0.022 mg/kg and copper of 0.051 mg/kg, and Borena milk had nickel, cadmium and lead below detection limits. Meat from Central Gonder contained copper of 1.5 to 11.5 mg/kg and lead of 0.42 to 1.5 mg/kg, generally below limits, though occasional cadmium values of up to 0.41 mg/kg approached or exceeded the 0.05 mg/kg threshold.

Fish from Ethiopian freshwater bodies accumulated some of the highest burdens recorded. Gilgel Gibe fish, including Labeo, Barbus and Nile tilapia, contained chromium of 10.31 to 19.53 mg/kg, lead of 3.08 to 10.04 mg/kg and cadmium of 0.35 to 1.6 mg/kg. Koka Lake fish carried cadmium up to 5.38 mg/kg and lead up to 13.1 mg/kg, while Lake Tana fish showed lead of 2.65 to 6.12 mg/kg. Hashenge Lake species contained lead of 0.88 to 1.24 mg/kg and cadmium of 0.58 to 1.66 mg/kg. Against fish limits of 0.3 mg/kg for lead and 0.05 mg/kg for cadmium, these are substantial exceedances. One anomalous copper measurement in Hawasa Lake fish, ranging up to 219.68 mg/kg, was flagged by the review as possibly reflecting a point source, spatial heterogeneity, or analytical problems such as matrix interference, incomplete digestion, calibration errors or inadequate quality control.

The review also examined how the measurements were made, and found that methodology itself limits confidence in comparisons. Flame atomic absorption spectrometry dominated, applied in most fruit, vegetable, cereal, meat, milk and fish studies because it is inexpensive and suitable for routine quantification, but it provides single-element analysis with lower sensitivity than modern alternatives. A smaller number of studies used ICP-MS, mainly in fish and fruit work, and ICP-OES in recent vegetable and milk studies, both offering lower detection limits and simultaneous multi-element determination. Mercury was measured by cold vapor atomic absorption combined with flame atomic absorption. The authors caution that variability in reported concentrations cannot be attributed to geography alone: sampling strategies, seasonal factors, digestion methods, detection limits and quality-assurance procedures all differed among studies and may explain inconsistencies for similar foods.

The authors conclude that lead, cadmium and chromium are the principal contaminants of concern and call for routine, risk-based national monitoring focused on these metals in high-risk commodities and locations, stronger enforcement of industrial wastewater discharge regulations, safer irrigation practices, and investment in laboratory capacity with harmonized sampling and quality-assurance protocols. They note significant limitations: most included studies reported concentrations without assessing dietary exposure or quantifying health risk, and publication bias may have shaped the evidence base. Future work, they argue, should move beyond isolated measurements toward nationally representative, longitudinal studies incorporating dietary exposure assessment, source attribution, bioaccessibility testing and quantitative human-health risk assessment to support effective food-safety policy in Ethiopia.

Subject of Research: Heavy metal contamination in crops, livestock products and fish in Ethiopia

Article Title: Heavy metal levels in crop and livestock product in Ethiopia: a review

Article References: Kefale, B., Woldeyes, F., Tessera, G. M., & Fanta, S. W. (2026). Heavy metal levels in crop and livestock product in Ethiopia: a review. Food Safety and Risk, 13(1), Article 39. https://doi.org/10.1186/s40550-026-00165-x

Image Credits: AI Generated

DOI: 10.1186/s40550-026-00165-x

Keywords: heavy metals, Ethiopia, food safety, lead, cadmium, chromium, systematic review, vegetables, fish, FAO/WHO limits, industrial contamination, public health