Islam et al. 2018 — Heavy metals in Tangail industrial-area food crops

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: Cr 0.45-47.7, Ni 0.22-38.6, Cu 0.43-47.4, As 0.72-6.05, Cd 0.001-6.70, and Pb 0.21-35.9.

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

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 iAs concentration.

Wiki pages this source may touch

• Rice
• Vegetables
• Non-root vegetables
• Beans
• fruits
• Rice (white, brown, wild — bulk grain)
• Non-Root Vegetables
• Legumes and Pulses, Other
• Fresh Fruit
• Chromium
• Nickel
• Copper
• Arsenic, Total
• Cadmium
• Lead

Verification notes

• PDF text extracted with pdftotext -layout; the extracted text contained the title page, DOI, methods, Table 1 concentration values, Table 4 EDI totals, and Table 6 arsenic-risk footnote.
• DOI verified from the first page as 10.1080/10106049.2018.1516246; DOI, raw-handle, and cite-key checks found no existing source page before creation.
• Table 1 values above were checked against the extracted table. Units are copied as mg/kg dw or mg/kg; no conversion was made.
• Speciation: arsenic is total As only. The source’s risk model assumed 50% inorganic As in foods, but no measured inorganic-arsenic values are reported. Chromium is total Cr only; no Cr(VI) is reported.
• Frontmatter product and ingredient slugs were checked against docs/gpt-collaboration/taxonomy-snapshot.md; no new slug was invented.
• Audit subagent 2026-06-09 (REVISE verdict) flagged matrices: [dry-weight, bangladesh-market, industrial-area-crops] for vocabulary review. Verified against source §2.1: samples were “collected by hand from the selected agricultural fields during March-April, 2016” — NOT market-collected. The bangladesh-market slug (an established country-market idiom in the corpus for retail-market surveys) was factually wrong on this page and was dropped; replaced with agricultural-field to capture the field-collected provenance, alongside the existing descriptive industrial-area-crops. dry-weight retained per controlled vocabulary.
• Source-internal discrepancy noted (not a wiki defect): the abstract and §2.1 state “Seventy five samples of eight different agricultural crops” and sample_n: 75 faithfully reports that figure, but the sum of Table 1 row-level n’s is 93 (57+3+9+6+6+3+5+4). Carry forward for any future synthesis pass that needs to weight rice-vs-vegetable contributions; the wiki uses the source’s stated sample size as authoritative.

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.