Overview
Gbedemah and colleagues measured mercury, lead and cadmium by AAS, plus coliform bacteria, in lettuce and bell pepper from three urban farm sites irrigated with stream or reservoir water, alongside a farmer survey. Tables 4 and 5 give one value per vegetable per site.
Key numbers
- Bell pepper mercury: 150 (Haatso), 280 (Dzorwulu) and 3090 (Weija) with the row unit printed as “μg mg x10000” and the header as mg/kg (Table 5).
- Lead 50 and cadmium 30 for every vegetable at every site (Tables 4 and 5).
Methods (brief)
Lead and cadmium by dry ashing with nitric acid and AAS; mercury by nitric acid and hydrogen peroxide digestion and cold-vapour AAS, after oven-drying at 105 C. No QA is reported.
Evidence Fitness
Weak quantitative evidence: one sample per vegetable per site, and the concentration units cannot be resolved (header, row label, text and abstract disagree), so values are stored unconverted with integrity flags. Identical lead and cadmium values everywhere suggest reporting limits rather than measurements. Wastewater-type irrigation (site context: wastewater). Bell pepper colour is not stated, so the green-bell-pepper page is not linked.