Unaegbu et al. 2016 - heavy metals in fruits sold in Enugu, Nigeria
This data article measured Ni, Cd, and Pb in ten fruit samples sold in Enugu, Nigeria, alongside nutrient and antioxidant endpoints. The heavy-metal result is straightforward: Cd and Pb were non-detect in all ten fruit samples, while Ni was detected in seven samples at 0.03-0.09 mg/L, with four samples slightly above the source-cited 0.07 mg/L WHO/USEPA comparator.
Key numbers
Heavy metals in fruit samples (Table 4; mg/L):
| Fruit group | Nickel | Cadmium | Lead |
|---|---|---|---|
| Apple sample A | 0.05 | ND | ND |
| Apple sample B | ND | ND | ND |
| Pineapple sample C | 0.03 | ND | ND |
| Orange sample D | 0.09 | ND | ND |
| Watermelon sample E | 0.09 | ND | ND |
| Banana sample F | ND | ND | ND |
| Pineapple sample G | ND | ND | ND |
| Banana sample H | 0.09 | ND | ND |
| Orange sample I | 0.08 | ND | ND |
| Watermelon sample J | 0.04 | ND | ND |
The authors state that Egyptian orange, Nigerian orange, Nigerian banana, and South African watermelon were slightly above the 0.07 mg/L WHO/USEPA maximum contaminant-level comparator used in the paper. Cd and Pb were non-detect in every fruit sample.
Methods (brief)
Fruit samples were purchased from Ogbete market in Enugu metropolis, Nigeria and analyzed at University of Nigeria, Nsukka. Heavy metals were measured by flame atomic absorption spectrophotometry after calibration-plot preparation. The source reports analytical wavelengths of 228.9, 283.3, and 341.5 nm for Cd, Pb, and Ni, respectively. Analyses were run in triplicate, with standard deviation used for precision. LOD was derived from reagent blank measurements; calibration curves used standard concentrations from 0.5 to 10 mg/dL. Statistical analysis used SPSS 16.0.
Implications
Standards work: This is small-n fresh-fruit occurrence evidence. It is useful as Nigerian-market confirmation that Pb and Cd may be non-detect in common table fruits while Ni can be measurable in some samples, but the sample count is too small for distribution synthesis.
Courses: Useful for teaching how source unit choices matter. The paper reports Ni, Cd, and Pb in mg/L even though the matrix is fruit homogenate/extract rather than drinking water; downstream users should not convert to mg/kg without the missing extraction-basis details.
App: Route as fresh-fruit occurrence evidence for Ni with Cd/Pb non-detect context. Do not infer compliance with EU fruit limits because the source uses a water-style WHO/USEPA comparator and reports extract units.
Microbiome: Not addressed.
Wiki pages this source may touch
Verification notes
- Fresh auto-fetch ingest 2026-05-19 from the ingredient-cell apple Cd wishlist. The paper measured multiple fruits and three metals; Cd was non-detect in all samples, but the source is retained because it supplies directly measured fresh-fruit occurrence data.
- Created provisional ingredient scaffold pineapple because the measured fruit panel includes pineapple and no pineapple ingredient page existed.
- Strict brand firewall: no sampled-product brands are named in this source page.
- The source uses mg/L for fruit heavy-metal results; this page preserves that unit and does not convert to mg/kg.
Page history
The five most recent substantive edits to this page. The full version history lives in git; when DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.