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Heavy Metal Index

Assessment of heavy metals in foods around the industrial areas: Health hazard inference in Bangladesh

Overview

Islam and colleagues measured chromium, nickel, copper, arsenic, cadmium, and lead in rice and seven vegetable/fruit crops grown around industrial areas of Tangail district, Bangladesh. The source reports crop concentrations in mg/kg dw and compares them with FAO/WHO food-crop limits. Arsenic is reported as total arsenic in the occurrence table; no inorganic arsenic speciation is provided.

Key numbers

The abstract reports all-sample concentration ranges in mg/kg: chromium (Cr) 0.45-47.7, nickel (Ni) 0.22-38.6, Cu 0.43-47.4, arsenic (As) 0.72-6.05, cadmium (Cd) 0.001-6.70, and lead (Pb) 0.21-35.9.

Table 1 reports metal concentration in food samples from the Tangail industrial area in mg/kg dw:

Plant samplenCr mean +/- SD (range)Ni mean +/- SD (range)Cu mean +/- SD (range)tAs mean +/- SD (range)Cd mean +/- SD (range)Pb mean +/- SD (range)
Rice5710.78 +/- 8.48 (0.45-32.49)5.38 +/- 4.46 (0.22-20.75)18.09 +/- 13.76 (0.43-47.69)1.87 +/- 1.16 (0.72-6.05)0.081 +/- 0.086 (0.001-0.37)4.34 +/- 4.35 (0.21-18.04)
Sponge gourd32.81 +/- 0.72 (2.27-3.63)3.55 +/- 0.98 (2.93-4.69)2.29 +/- 0.63 (1.56-2.72)2.92 +/- 0.76 (2.05-3.41)12.09 +/- 3.02 (8.69-14.49)30.37 +/- 7.91 (21.25-35.42)
Bitter gourd928.72 +/- 9.99 (14.35-47.67)21.43 +/- 5.21 (15.2-29.84)17.21 +/- 5.01 (9.67-24.17)1.52 +/- 0.39 (1.01-2.03)3.15 +/- 2.13 (0.81-6.70)5.96 +/- 1.76 (3.34-8.53)
Papaya621.23 +/- 11.35 (8.69-26.30)20.03 +/- 4.79 (13.40-26.30)20.64 +/- 5.02 (13.67-25.45)1.91 +/- 0.79 (0.79-2.99)1.26 +/- 0.30 (0.84-1.69)6.65 +/- 2.52 (3.92-10.20)
Okra623.42 +/- 5.79 (15.22-28.51)31.04 +/- 7.70 (20.49-38.62)18.02 +/- 5.64 (9.93-24.97)2.55 +/- 0.70 (1.53-3.64)2.86 +/- 1.39 (1.35-4.84)21.12 +/- 11.34 (8.32-35.87)
Bean318.16 +/- 4.88 (12.52-21.10)18.47 +/- 4.64 (13.21-22.03)12.48 +/- 3.25 (8.73-14.56)1.67 +/- 0.42 (1.26-2.11)1.58 +/- 0.64 (0.94-2.25)7.10 +/- 2.11 (4.71-8.74)
Brinjal521.78 +/- 11.07 (10.40-33.40)21.30 +/- 8.08 (11.81-33.21)16.97 +/- 7.26 (9.03-27.75)2.12 +/- 0.54 (1.57-2.88)0.87 +/- 0.23 (0.64-1.26)7.01 +/- 2.11 (3.77-9.49)
Chili416.41 +/- 6.22 (8.12-21.57)22.00 +/- 5.60 (17.97-30.20)11.55 +/- 5.05 (6.22-16.66)2.15 +/- 0.59 (1.48-2.91)1.12 +/- 0.31 (0.81-1.43)13.48 +/- 9.86 (7.32-28.18)

Additional source-reported numbers:

  • Table 1 lists FAO/WHO 2011 permissible levels as Cr 2.3, Ni 10, Cu 40, As 0.1, Cd 0.05, and Pb 0.1 mg/kg.
  • The text states the highest mean Cr was in bitter gourd at 28.72 mg/kg, and the lowest was in sponge gourd at 2.81 mg/kg.
  • The highest mean Ni was in okra at 31.04 mg/kg, and the lowest was in sponge gourd at 3.55 mg/kg.
  • The highest mean Cu was in papaya at 20.64 mg/kg, and the lowest was in sponge gourd at 2.29 mg/kg.
  • The text reports mean Pb in descending order beginning with sponge gourd 30.37, okra 21.12, and chili 13.48 mg/kg.
  • Table 4 total daily intake via food consumption for adults was Cr 8.816, Ni 8.066, Cu 8.491, As 1.114, Cd 1.189, and Pb 5.511 mg/day.
  • Table 4 total daily intake via food consumption for children was Cr 5.424, Ni 5.203, Cu 4.810, As 0.658, Cd 0.805, and Pb 3.519 mg/day.
  • Table 6 notes that carcinogenic-risk calculations assumed 50% inorganic As in foods; this is not a measured inorganic-arsenic concentration.

Methods (brief)

The study selected agricultural fields around industrial areas of Tangail district, Bangladesh, near textile, metal-processing, dyeing, brick-kiln, battery-manufacturing, and leather activities. At each station, the same species of cereal or vegetable were collected as sub-samples and mixed into composite samples. Consumable portions were washed with distilled water, cut, oven-dried at 70-80 °C to constant weight, and analyzed after microwave digestion of 0.2-0.3 g dried sample with 1.5 mL 69% HNO3 and 4.5 mL 35% HCl in a closed Teflon vessel. Heavy metals were measured by ICP-MS (Agilent 7700 series), with NIST 1547 peach leaves used as CRM in each sample batch.

Implications

This source contributes dry-weight Bangladesh industrial-area crop occurrence evidence for rice, non-root vegetables, bean/legume crops, and papaya. The values are dry-weight concentrations from field-grown crops and should not be mixed with fresh-weight market-basket food values without an explicit basis conversion. Arsenic is total As occurrence data; the paper’s 50% inorganic-As risk assumption should not be treated as an extracted inorganic arsenic (iAs) concentration.

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.

CommitDateChangeDescription
b01ec52c312026-08-04major1 section added
3171d069e32026-08-02major1 section added
90a2f9a38e2026-07-30major1 section added and 1 removed; narrative text revised
eaa8eeeedf2026-07-27major1 section added and 1 removed
50de6ab2172026-07-27minorNarrative text revised