Overview
Naser and colleagues sampled onion, garlic and chilli plants and their soils from fields irrigated with industrial wastewater, fields flooded by contaminated ponds, and a clean research station in Gazipur. Tables 1 to 3 give mean ± SD lead, cadmium and nickel for roots, bulb or fruit, leaves and the whole plant on a dry-weight basis. Edible parts from polluted fields carried several times more lead and cadmium than those from the clean site.
Key numbers
- Onion bulb lead: 6.42 (directly polluted), 3.62 (indirectly polluted), 1.20 µg/g dry wt. (non-polluted); cadmium 1.62, 1.10 and 0.60 µg/g (Table 1, p. 125).
- Garlic bulb lead 7.54, 5.28 and 2.64 µg/g; cadmium 1.80, 0.84 and 0.64 µg/g dry wt. (Table 2, p. 126).
- Chilli fruit lead 6.10, 5.26 and 3.38 µg/g; cadmium 1.50, 1.20 and 0.82 µg/g dry wt. (Table 3, p. 127).
Methods (brief)
Plants were washed, oven-dried at 65 °C, ground, digested with nitric and perchloric acids and read on a Varian AAS. Each sample was analyzed three times. No detection limit, reference material or recovery is reported, and the number of plants per site is not given.
Evidence Fitness
A small field comparison centred on wastewater-irrigated industrial land, so it shows a contamination contrast rather than typical market levels. Two table errors are flagged. In Table 1, onion whole-plant cadmium and nickel repeat the lead column. In Table 2, garlic whole-plant lead repeats onion’s values. Dry onion, garlic and chilli are seasoning proxies for barbecue-sauce and ranch-dressing; those pages are not linked.