Naser et al. 2018 - metals in spinach and other leafy vegetables in Bangladesh

Naser and coauthors measured Pb, Cd, Ni, Co, and Cr in spinach (Spinacia oleracea), red amaranth (Amaranthus tricolor), and amaranth (Amaranthus oleraseus) grown across a three-tier pollution gradient in Gazipur, Bangladesh: two industrial sites irrigated with Turag river water (high pollution, Kalakoir) or pond/kennel water (medium pollution, Zorun, Konabari) and one non-industrial experimental field (low pollution, BARI). The source is routeable to spinach and to leafy-vegetables-other because leaf and whole-plant tables report explicit dry-weight concentrations by species and by pollution level. Industrial-area findings should be kept jurisdiction- and site-contextual.

Key numbers

• Spinach leaves in high-pollution areas: Pb 5.97 +/- 0.30, Cd 1.02 +/- 0.15, Ni 31.9 +/- 3.38, Co 1.63 +/- 0.24, and Cr 5.70 +/- 0.36 ug/g dry weight.
• Spinach leaves in medium-pollution areas: Pb 3.61 +/- 0.18, Cd 0.52 +/- 0.03, Ni 24.6 +/- 2.23, Co 1.41 +/- 0.17, and Cr 5.62 +/- 0.23 ug/g dry weight.
• Spinach leaves in low-pollution areas: Pb 1.16 +/- 0.16, Cd 0.43 +/- 0.07, Ni 5.48 +/- 0.47, Co 0.47 +/- 0.09, and Cr 2.69 +/- 0.24 ug/g dry weight.
• Whole-plant spinach values were Pb 5.07 +/- 0.79, Cd 1.14 +/- 0.31, Ni 33.2 +/- 11.2, Co 1.60 +/- 0.27, and Cr 6.09 +/- 0.85 ug/g dry weight in high-pollution areas.
• Regulatory comparison: authors compare whole-plant means against the FAO/WHO-Codex Alimentarius (1984) safe limits cited in the paper as Pb 5, Cd 0.3, Ni 20, Co 50, and Cr 5 ug/g dry weight. Cd in spinach and amaranth exceeded the Cd limit even in the low-pollution (BARI) field; Pb, Ni, and Cr exceeded their respective limits in vegetables from the polluted areas; Co stayed below its limit across all sites.

Methods (brief)

Plant parts and corresponding soils were collected from two industrial areas (Kalakoir and Zorun, Konabari, Gazipur) and one non-industrial area (BARI experimental field) from 6-week-old plants. Roots, stem, and leaves were separated. Samples were oven-dried at 65 C for 72 to 96 h, ground in a ceramic-coated grinder, then digested with HNO3:HClO4 (5:1 volume) for 1.5 h at about 190 C. Concentrations were determined in triplicate by atomic absorption spectrophotometry (VARIAN AA2407 AAS) and reported in ug/g on a dry-matter basis. Statistical differences were judged by Tukey’s multiple comparisons in Excel Statistics 4.0 (Esumi Co. Ltd., Tokyo, Japan).

Implications

Certification: site-specific Bangladesh spinach evidence for Pb, Cd, Ni, Co, and Cr. Courses: strong example of plant-part and pollution-gradient separation. App: supports high-risk industrial-area sourcing context, not a general-market spinach value.

Wiki pages this source may touch

• Spinach
• Leafy / Green Vegetables, Other
• Spinach
• Leafy Vegetables
• Lead
• Cadmium
• Nickel
• Cobalt
• Chromium

Verification notes

Values were transcribed from Tables 3 and 4 in the PDF text extraction. Units are ug/g dry weight; conversion to ppb dry weight requires multiplying by 1000 and must be logged if used downstream.

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.