Ullah et al. 2022 - Khyber Pakhtunkhwa vegetables heavy metals

Ullah et al. (2022) measured Pb, Cr, Cd, Cu, Zn, Ni, Fe, and Mn in water, soil, and nine edible vegetable types from peri-urban D.I. Khan, Khyber Pakhtunkhwa, Pakistan. The routeable occurrence values are the edible-vegetable metal ranges for wastewater-irrigated sectors X/Y and freshwater-irrigated sector Z. Water and soil values are pathway context and should not be pooled with vegetable occurrence values.

Key numbers

Figure 2 gives the vegetable-by-sector bar plots, while the results text reports exact concentration ranges in mg kg-1. The wastewater-irrigated sectors X and Y were reported together as Pb 7-41, Cr 6-38, Cd 1.8-7.5, Cu 11.7-27, Zn 7.9-34.9, Ni 15.6-61.2, Fe 7.2-39.3, and Mn 12.4-60.4 mg kg-1. The freshwater-irrigated sector Z was reported as Pb 4.0-7.0, Cr 3-27.7, Cd 0.3-1.4, Cu 7.5-14.5, Zn 3.3-16.7, Ni 4.1-28.7, Fe 2.8-57.3, and Mn 1.6-22.2 mg kg-1.

The nine vegetable types were cauliflower, tinda, spinach, cabbage, carrot, taro/Colocasia, radish, turnip, and lettuce. The paper states that Pb, Cd, Cr, and Ni in sectors X and Y were above the WHO norm, and that in sector Z the three heavy-metal concentrations Pb, Cr, and Cd were recorded with unusually high Ni in spinach and tinda.

Table 3 reports soil-to-vegetable transfer factors. For Cd, the highest reported TFs were 3.478 in sector X Colocasia, 3.741 in sector Y turnip and Colocasia, and 9.333 in sector Z radish. For Ni, the highest reported TFs were 0.855 in sector X lettuce, 0.949 in sector Y lettuce, and 12.766 in sector Z spinach.

Tables 4-6 report EDIM and HRI values for adults and children. The wastewater-sector tables report high adult HRI values for Cd: sector X Colocasia 1.72E+02, carrot 1.43E+02, cabbage 1.31E+02, and lettuce 1.31E+02; sector Y Colocasia 1.73E+02, turnip 1.73E+02, carrot 1.54E+02, and lettuce 1.38E+02. In freshwater sector Z, adult HRI values in Table 6 were all below 1, including Cd 7.33E-01 in Colocasia, 6.81E-01 in cabbage and radish, 6.28E-01 in spinach, cauliflower, and lettuce, 5.76E-01 in carrot, 4.71E-01 in tinda, and 3.14E-01 in turnip.

Methods (brief)

The study sampled three sectors around D.I. Khan between October 2019 and April 2020. Sectors X and Y had a long history of mixed city-runoff and textile-industry wastewater irrigation, while sector Z used underground freshwater. The edible portions of vegetables were washed, acidified with 0.1 M HCl for 30 min, rinsed with distilled water, oven-dried for 24 h at 60 °C, powdered, digested with HNO3, H2SO4, and HClO4, and analyzed by atomic absorption spectrophotometry. The authors report repeated analysis against NIST plant standard reference material with results within +/- 1% of certified values.

Implications

This source supports wastewater-irrigated vegetable occurrence context for leafy vegetables, spinach, root/tuber vegetables, and non-root vegetables in Pakistan. It should be routed as local peri-urban agricultural evidence, not as a national Pakistan vegetable baseline. The product values should remain separated from the water and soil tables because the latter are exposure-pathway context rather than edible-product concentrations.

Wiki pages this source may touch

• spinach
• cabbage
• cauliflower
• carrot
• lettuce
• root-vegetables
• non-root-vegetables
• leafy-vegetables
• spinach
• leafy-vegetables-other
• root-tuber-vegetables
• non-root-vegetables
• lead
• chromium
• cadmium
• copper
• zinc
• nickel
• iron
• manganese

Verification notes

• Identity checks before writing found no existing DOI, raw-handle, or cite-key page for 10.1007/s12011-021-02892-y, MFK_health-risk-assessment-and-multivariate-statistic, or ullah2022-khyber-vegetables-metals.
• The concentration values above come from the results text because Figure 2 contains the vegetable-by-sector concentration plots without a numeric table in the PDF text layer. No bar heights were estimated from the figure.
• Units preserved: vegetable concentrations remain in mg kg-1; water concentrations remain separate in mg L-1; soil concentrations remain separate in mg kg-1. No unit conversions were performed.
• Basis: the paper cleaned, acid-washed, oven-dried, and powdered edible vegetable portions before digestion; the reported vegetable concentrations are preserved in the source’s mg kg-1 basis.
• Source-side consistency caveat: the abstract says corresponding HRI values were below 1, but Tables 4 and 5 report many HRI values greater than 1 for wastewater-irrigated vegetables. This page reports the tables and records the contradiction.
• Matrix separation: water and soil concentrations are not product occurrence values.
• Missing slug note: the taxonomy snapshot has no exact tinda, taro, Colocasia, radish, or turnip ingredient/product slug. Frontmatter uses broad existing root/tuber, leafy, non-root vegetable, and spinach slugs.
• No brand names were present.

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.