Overview
The authors bought cabbage and cauliflower in open markets of the three Kathmandu Valley districts in 2012 and measured arsenic, cadmium, copper, mercury, lead and zinc by AAS on dried material. Arsenic and mercury were not detected. Lead and cadmium were well above the FAO/WHO limits they cite. The article is printed as volume 15, issue 1 (2014); the manifest lists 2015.
Key numbers
- Cabbage leaves, mean of three districts (Table 2, mg/kg dry weight): cadmium 1.56 (SD 0.55), lead 10.54 (3.79).
- Cauliflower, mean of three districts (Table 3, mg/kg dry weight): cadmium 1.22 (0.36), lead 15.70 (5.24).
- Arsenic and mercury were not detected in either vegetable at any site (Tables 2-3).
Methods (brief)
One gram of dried powder was digested in a nitric, perchloric and sulfuric acid mixture at 80 °C and read on a Perkin-Elmer 2380 AAS. Standard solutions were run often; no reference material, recovery or detection limit is reported.
Evidence Fitness
Only three samples per vegetable and district (18 in total), from one season, with little quality control. The grocers said the produce was grown along polluted riversides, so it may not represent ordinary supply. Results are dry weight. Lead values of 7 to 21 mg/kg are high for brassicas. Cabbage and cauliflower bear directly on non-root vegetables.