Assessment of trace metals in five most-consumed vegetables in the US: Conventional vs. organic

Determination of cadmium and lead in tomato (Solanum lycopersicum) and lettuce (Lactuca sativa) consumed in Quito, Ecuador

“…In the present study, the samples from organic markets (bioferias) had Cd and Pb content in tomatoes and lettuce greater than that from the other three market groups selling nonorganic products. Further, the Cd content found by the present study and the results of Hadayat et al [ 38 ] are contradictory. There has been a significant increase in consumer demand for organic products, which are marketed as such because of the relatively low use of chemicals in their cultivation and less processing.…”

“…The maximum Cd concentration obtained in tomatoes (0.660 mg/kg, dry weight) in the current study was three times higher than that reported by Mohod [ 36 ] from Amravati, India, but lower than that reported by Labhade [ 37 ] from Nashik, Murad Basha et al [ 46 ] from Andhra Pradesh, India, and quite lower than that reported by Murad Basha et al [ 44 ] from Jamaica. Further, the concentrations reported by Hadayat et al [ 38 ] from Florida (USA) in both organic and nonorganic tomatoes were considerably lower than those from the present study, the same happened with the concentrations reported by Marín et al [ 45 ] from Valencia. For Cd content in lettuce, the dry weight results obtained by the present study were largely lower than those reported in Croatia [ 1 ], Argelia [ 5 ], and India [ 37 ], but higher than the value assessed in Valencia [ 45 ].…”

“…When comparing the results between nonorganic and organic crops (bioferias), considering the values from the present study and those reported by Hadayat et al [ 38 ], the metal content is completely different. Hadayat et al [ 38 ] describe that in the analyses of organic market products, the TM concentration was lower than that found in nonorganic crops; the authors suggest this is due to the non-use of metal-based pesticides. In the present study, the samples from organic markets (bioferias) had Cd and Pb content in tomatoes and lettuce greater than that from the other three market groups selling nonorganic products.…”

Comparative Effects of Organic and Conventional Cropping Systems on Trace Elements Contents in Vegetable Brassicaceae: Risk Assessment

“…This could be explained by considering that turnip greens are the vegetative Brassica rapa leaves, whereas the turnip tops are the fructiferous stems with flower buds and the surrounding leaves. Previous studies have indicated that metals tend to accumulate preferentially in roots rather than in storage organs or fruits [17,18]. Moreover, unlike what happens to the turnip greens, statistically significant differences were found for Cu (p < 0.05) and Zn (p < 0.01) between the conventional and organic turnip tops grown on Farm II, the highest concentrations being found in the organic ones.…”

The Effect of Different Organic Fertilizers on Yield and Soil and Crop Nutrient Concentrations

“…Wheat grain Zn concentrations were found to more than double with sewage sludge applications over 4 years in UK field experiments [28]. The concentration of secondary and micro nutrients Mg, Fe, K, Ca, and Mn of the edible part of vegetables was greater when grown in organic compared with conventional farms [29], whereas heavy metal toxicant concentrations of vegetables were greater when grown in conventional rather than organic systems [30]. It was observed in rice that uptake of P and K was greater with chicken manure than compost treatment, whereas uptake of N, Ca, and Mg was greater with compost treatment [31].…”