Detection of Heavy Metals in Some Edible

Overview

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crops, the mean concentrations of Cd, Cr, Cu, Fe, Pb, and Zn were 0.06, 0.49, 0.21, 1.16, 0.15, and
0.17mg/kg respectively. Meanwhile, crops from Muda Lawal market exhibited mean concentrations of
0.06, 0.58, 0.17, 1.62, 0.1, and 0.22 mg/kg for Cd, Cr, Cu, Fe, Pb, and Zn, respectively. Cd, Cr, Cu,
(FAO), grains contribute to more than 50% of the global caloric intake (FAO, 2021). Common
separately. Fifteen (15) mL of tri-acid mixture (70% high purity (Nitric acid) HN03, 65%
(Perchloric acid) HCl04 and 70% (Sulfuric) H2S04 in 5:1:1 ratio) was added. The
The concentration of heavy metals in crops from the central market (Table 1) exhibited
Oryza sativa, and Sorghum bicolor, the levels of Cd ranged from 0.01 to 0.06 mg/L, Cr ranged
mg/kg, Pb ranged from 0.01 to 0.15 mg/kg, and Zn ranged from 0.06 to 0.17 mg/kg. Cd and
Table1: Concentration of heavy metals in the assayed grains obtained from Central market,
Table 2: Concentration of heavy metals in the assayed grains obtained from Muda Lawal
different grains assayed. Cd levels ranged from 0.01 to 0.06 mg/kg, Cr ranged from 0.19 to
0.58 mg/kg, Cu ranged from 0.02 to 0.17 mg/kg, Fe ranged from 0.2 to 1.62 mg/kg, Pb ranged
from 0.07 to 0.1 mg/kg, and Zn ranged from 0.06 to 0.22 mg/kg in Phaseolus vulgaris, Zea mays,
Table 3 displays the EDI of metals from consuming grains sourced from the central market.
The EDI results indicate a range of 0.01 to 0.76 mg/kg/bw/day for Cd, 0.01 to 0.56
mg/kg/bw/day for Cr, 0.02 to 0.17 mg/kg/bw/day for Cu, 0.03 to 1.33 mg/kg/bw/day for
Fe, 0.01 to 0.61 mg/kg/bw/day for Pb, and 0.06 to 0.76 mg/kg/bw/day for Zn. The results
Table 3: Estimated daily intake of grains obtained from Central market, Bauchi.
Table 4: Estimated daily intake of crops obtained from Muda Lawal market, Bauchi.
The data presented in Table 4 illustrates the EDI of metals resulting from the consumption of
exhibited a range of 0.01 to 0.76 for Cd, 0.11 to 0.6 for Cr, 0.01 to 0.19 for Cu, 0.12 to 1.06 for
Table 5: Hazard quotient and hazard index of grains obtained from central market, Bauchi.
guinea corn. The combined HI for all the metals studied ranged from 0.01199 in red guinea
Table 6: Hazard quotient and hazard index of crops obtained from Muda Lawal market.
which ranged from 0.33-4.68, 0.67-16.83, 9.01-43.675, 1.75-38.08 and 0.17-20.80mg/kg of Cd,
et al. (2022), where Pb and Cd were below the detection threshold, and Cu and Zn ranged
from 0.023 to 0.039 and 0.003 to 0.042 mg/kg, respectively. Wei et al. (2023) also reported heavy
mg/kg for Cd and Cr respectively). However, Pb exhibited a higher concentration (0.065
Plateau state by Bawa et al. (2021a) in crops sprayed with pesticides which ranged from 0.5-
also lower than those found by Bawa et al. (2023) in Kaduna state, Nigeria which ranged from
0.13-1.33, 0.25-1.50, 3.17-31.8, 0.50-5.33 and 14.08-44.00 mg/kg of Cd, Cr, Cu, Pb and Zn
Furthermore, Liu et al. (2020) reported the mean concentration of Cd, Cu, Cr, Pb and Zn in
this study. Moreover, Sharma and Bisla (2022) reported the mean concentration of Cd and Pb
in Phaseolus vulgaris obtained from a local market in India to be 0.27 and 0.19 mg/kg
17.5 mg/kg respectively. The differences in heavy metal concentrations in crops of the
within the acceptable RfD for Cu, suggesting no significant risk. Bawa et al. (2021a) reported
reported by Ahmad et al. (2023) ranged from 0.0055 to 0.0115 for Pb and Zn in barley, maize,
which ranged from 0.01199 to 0.79132 (for grains obtained from central market) and 0.01123
S., Abdel-Hameed U. K., Ali I. (2023). Amassing of heavy metals in soils, vegetables
metals in vegetables and potential risk for human health. Sci Agric, 68(1): 54-60
and vegetables of Dar es Salam, Tanzania. J Chem., 2018: 1-9.

Methods (brief)

the grains and evaluating associated health risks. We utilized Atomic Absorption Spectrophotometry
following acid digestion of grains to determine heavy metal concentrations. In Central market-sourced
Lawal and Central markets in Bauchi town. Samples were collected and stored in polythene
The dried samples were crushed using a stainless steel blender and passed through a 2 mm
Samples of grains from the markets (1.00±0.001 g each) were placed into 100 mL beakers
analysed for Cd, Cr, Cu, Fe, Pb and Zn, using an atomic absorption spectrophotometer (210
and soils collected from intensively cultivated areas of Sri Lanka. Sri Lanka: Pedologist,
Sharma D., Bisla G. (2022). Assessment of heavy metals in fruits and vegetables collected from

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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. When DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.

Commit	Date	Change	Description
b01ec52c	2026-08-04	major	2 sections added
d49e450f	2026-08-03	major	5 sections added; narrative text revised