Heavy metals in vegetables: screening health risks involved in cultivation along wastewater drain and irrigating with wastewater

Overview

Sharma, Katnoria, and Nagpal measured cadmium, lead, copper, cobalt, and iron in edible portions of 12 vegetable types collected from three Amritsar, Punjab agricultural settings: two groundwater-irrigated sites beside the Tung-Dhab drain and one municipal-wastewater-irrigated site. The paper is routeable for contaminated-site vegetable occurrence evidence, especially spinach, because it reports exact prose values for spinach cadmium, cobalt, and copper and shows lead and metal-pollution results in figures. It should not be pooled silently with ordinary retail-market spinach because all sites were selected for wastewater-drain exposure or wastewater irrigation.

Key numbers

• Derived sample accounting: 12 common vegetables from three sites; edible parts were collected in triplicate from each site, implying 108 vegetable-site replicate samples.
• Site 1: groundwater-irrigated fields across the Tung-Dhab drain near industrial discharges; Site 2: groundwater-irrigated fields 15 km downstream; Site 3: municipal-wastewater-irrigated fields on the south side of Amritsar.
• Across all three sites, the source reports the general uptake pattern as Fe > Co > Cu > Cd > Pb.
• Cadmium: at Site 1, fenugreek had 0.8 mg/kg and spinach followed at 0.6 mg/kg. The paper reports the overall maximum cadmium value as 1.2 mg/kg in radish from Site 2, with Site 2 turnip at 0.87 mg/kg and Site 3 turnip, fenugreek, and radish at 1.06, 1.0, and 0.8 mg/kg, respectively.
• Cobalt: spinach had the maximum cobalt concentration at Site 1 and Site 3, reported as 92 mg/kg and 130.67 mg/kg, respectively; Site 2 maximum cobalt was coriander at 69 mg/kg.
• Copper: spinach from Site 1 had the highest copper value reported in the Results prose, 80.33 mg/kg.
• Lead: Figure 6 reports lead by vegetable and site. The prose states that 7 of 12 vegetables from Site 3 exceeded the leafy-vegetable permissible concentration cited by the paper, and that some Site 1 and Site 2 vegetables also exceeded the cited limit; exact spinach lead values are graph-only in the PDF text extraction and are not transcribed here as numeric evidence.
• Metal pollution index: spinach had the highest MPI rank at Site 1 and Site 2; at Site 3 the MPI rank was fenugreek, coriander, mint, then spinach.
• Hazard quotient: the paper reports that spinach from Site 1 had the highest copper hazard quotient and that spinach from all sites could be highly hazardous for children under the source’s minimum vegetable-intake assumptions.

Methods (brief)

The authors washed edible vegetable portions with distilled water, air-dried them, oven-dried them at 70 deg C, crushed the dried samples, digested 0.5 g dry vegetable with a tri-acid mixture, and made the digest to 50 ml. Cadmium, copper, cobalt, iron, and lead were analyzed using an Agilent 240FSAA atomic absorption spectrophotometer. Values are treated as dry-weight edible-portion concentrations because the method dries samples before digestion and reports mg/kg concentrations without a fresh-weight conversion. The paper reports total elemental concentrations only; no speciation is provided.

Implications

• Certification (HMTc): Adds contaminated-site context for spinach and broader vegetables in India. The source is useful for stress-testing market/geography stratification but should not be pooled with ordinary US-market or retail spinach without an explicit contaminated-site sensitivity flag.
• Courses: Useful case study for explaining how groundwater-adjacent drains and wastewater irrigation can both elevate metals in leafy vegetables, and why row-fit, geography, and cultivation setting must be recorded before pooling.
• App: Supports spinach and leafy-vegetable warning/context modules for contaminated irrigation settings, especially Cd/Cu/Co signals and the child hazard-quotient discussion.

Wiki pages this source may touch

• Spinach
• Vegetables
• Leafy Vegetables
• Root vegetables
• Non-root vegetables
• Spinach
• Leafy / Green Vegetables, Other
• Root and Tuber Vegetables
• Non-Root Vegetables
• Cadmium
• Lead
• Copper
• Cobalt

Verification notes

• DOI, title, author byline, year, and journal were taken from the PDF title page and metadata.
• The paper’s figures show additional vegetable-specific metal bars, including lead, but the PDF text extraction does not expose exact graph values. Structured evidence rows from this ingest therefore include only exact values stated in prose.
• The concentration basis is dry-weight edible portion by method inference from oven-drying at 70 deg C before digestion and mg/kg reporting; the source does not explicitly print “dry weight” beside each concentration table or figure, and no source-provided fresh-weight conversion was found.
• The abstract reports the highest copper value as 81.33 mg/kg, while the Results prose reports spinach from Site 1 at 80.33 mg/kg. This page uses the Results prose value and records the discrepancy for audit traceability.
• The source covers leafy, root, fruiting, and bulb vegetables, but matrices is limited to current common matrix terms. The broader non-root and mixed-vegetable scope is carried by ingredient and product slugs.
• This is not a retail-market or US-market survey. Route as contaminated-site / wastewater-irrigation context unless governance explicitly admits it into a separate contaminated-site sensitivity pool.

Update history

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