Occurrence and accumulation of metals in lupine seeds in Ethiopia

Overview

Woreta et al. (2023) measured chromium (Cr), Mn, Fe, Co, nickel (Ni), Cu, Zn, cadmium (Cd), and lead (Pb) in lupine seeds and paired agricultural soils from four districts of South Gondar Zone, Ethiopia. The routeable occurrence values are the Table 4 seed concentrations in mg/kg; Table 5 soil values and Table 7 bioaccumulation factors are pathway context and should not be pooled as product concentrations. The paper reports total-element measurements only, with no arsenic, mercury, or chromium speciation.

Key numbers

The abstract and conclusion summarize the same seed ranges as Mn 292-309 mg/kg, Co 44.5-48 mg/kg, Fe 148-155 mg/kg, Zn 92.5-98.8 mg/kg, Ni 68.5-73.4 mg/kg, Cu 85.4-92.2 mg/kg, Cr 36.6-39.9 mg/kg, Cd 9.23-10.5 mg/kg, and Pb 12.2-12.7 mg/kg. The paper states that Mn, Co, Fe, and Zn were below its cited maximum allowable limits, while Ni, Cu, Cr, Cd, and Pb exceeded those source-listed limits.

Table 5 reports paired soil concentrations in mg/kg: Cr 53.3 +/- 0.9 to 60.5 +/- 1.2, Mn 566 +/- 1 to 577 +/- 1, Fe 332 +/- 1 to 337 +/- 2, Co 64.9 +/- 0.1 to 75.5 +/- 1.0, Ni 83.1 +/- 0.0 to 103 +/- 0, Cu 148 +/- 1 to 160 +/- 1, Zn 191 +/- 2 to 197 +/- 1, Cd 17.7 +/- 0.2 to 18.2 +/- 0.1, and Pb 20.9 +/- 0.1 to 21.4 +/- 0.1. The authors report that soil Co, Ni, Cu, and Cd exceeded their cited WHO soil limits, while Cr, Mn, Fe, Zn, and Pb were below those limits.

Table 7 reports bioaccumulation factors below 1.0 for every metal and district. The lowest BAF in the table is Fe 0.448 at Dera, and the highest is Ni 0.824 at Farta. The text states that BAF values were between 0.4 and 1.0, indicating transfer from soil to crop without BAF values above unity.

Methods (brief)

The study collected lupine seed and topsoil samples from Estie, Andabet, Dera, and Farta in South Gondar Zone between October and December 2020. Seed samples were rinsed with deionized water, air-dried, pulverized, sieved through 105 micrometer, and stored refrigerated. A 0.5 g seed aliquot was digested with 1 mL HNO3 and 5 mL HClO4 at 200 degrees C for 60 min, diluted to 50 mL, and analyzed by flame atomic absorption spectrophotometry using a Buck Scientific Model 210VGP AAS. Soil samples were collected from 0-20 cm topsoil, dried, sieved, digested separately, and analyzed with the same instrument. The method reports seed LODs from 0.031 to 0.235 mg/kg, seed LOQs from 0.101 to 0.785 mg/kg, and recovery ranges of 93.75% to 117.17% for lupine and 82.39-108.74% for soil.

Implications

This source adds Ethiopian lupine-seed occurrence data for the broad legumes/pulses product family, with paired soil measurements documenting a soil-to-crop pathway. Because the paper reports district-level composite means rather than individual sample measurements, downstream evidence use should retain the district and composite-sampling context. Soil-only concentrations should remain exposure-pathway context and should not be routed as edible lupine occurrence values.

Related evidence

• Legumes and Pulses, Other
• Legumes
• Chromium
• Manganese
• Iron
• Cobalt
• Nickel
• Copper
• Zinc
• Cadmium
• Lead

Update history

The five most recent substantive edits to this page, classified major (evidence or structure moved), correction (a published value or statement was wrong and has been fixed), or minor (narrative rewritten without changing the underlying evidence). Each description is derived from what the edit did to this page; the linked commit is the authoritative record, routine regeneration passes are excluded, and the full version history lives in git.