Overview
Norton and colleagues measured cadmium and lead by ICP-MS in about 1,300 samples of locally grown produce from a historically mined region (Devon and Cornwall) and a lightly mined one (Aberdeenshire). Only 0.2% of samples exceeded the EU cadmium limit and 0.6% the lead limit. Peeling lowered both metals in potatoes and swedes, and baked potato skin held far more lead than the flesh.
Key numbers
- Potato (peeled), SW: cadmium mean 7.2, max 21.5 ng/g; lead mean 5.0, max 26.8 ng/g fresh weight, n = 82 (Tables 2 and 3).
- Potato (peeled), NE: cadmium mean 18.5 ng/g, lead mean 7.6 ng/g fresh weight, n = 28 (Tables 4 and 5).
- Lettuce, SW: cadmium mean 16.6, lead mean 27.0 ng/g fresh weight, n = 42 (Tables 2 and 3).
- Baked potato, n = 20: lead 162.7 ng/g in skin vs below 8 ng/g in flesh (Results, p. 10).
Methods (brief)
Produce was washed in tap water as for cooking, prepared as commonly eaten (potatoes and roots peeled, apples and courgettes unpeeled), pureed, dried at 70 °C and microwave digested; ICP-MS with rhodium internal standard. Four plant CRMs gave cadmium recoveries of 84 to 94% and lead 70 to 91%. Laser ablation ICP-MS located the metals in the outer 0.4 to 0.9 mm of potato.
Evidence Fitness
Large, well-documented survey with CRM control, though lead recoveries were low for two CRMs. The file is the accepted author manuscript, not the typeset article. The basket LOD is not stated and the tables carry floor values (1.8 ng/g cadmium, 4.0 ng/g lead) that look like substitutions for non-detects. Direct for non-root vegetables. Raw peeled potato is a proxy for cream-of-potato-soup, and no soup was measured, so the soup pages are not linked.