Cadmium is a toxic element for all living beings, even at low concentrations, and it is a human carcinogenic according to IARC. Since food is reported as the main source of Cd intake in non-smoking individuals, FAO and WHO set limits for the maximum permitted human intake. Leafy vegetables have a relatively high potential for Cd uptake and translocation, therefore they are often considered Cd accumulators. As they are important salad crops of the Mediterranean diet and are available worldwide, their consumption may represent an effective risk for human health. Lettuce (Lactuca sativa) and endive (Cichorium endivia), grown on different agricultural soils in Campania region (southern Italy), subjected to different fertilisation treatments (unfertilisation, compost amendment and mineral fertilisation), were analysed to clarify if the highest concentrations found are linked to external (older and inedible) or internal (younger and edible) leaves. All the leafy vegetables analysed showed on average 2-fold higher (α=0.05) Cd concentrations in leaves than in roots. Leaf Cd concentrations in both lettuce and endive significantly differed among fertilisation treatments, with values highest in the plants grown on mineral fertilised soils. Apart from the soil fertilisation treatments, however, Cd leaf concentrations were often higher than maximum levels deduced by the CE 629/2008 Regulation. External leaves of endive plants showed significantly higher (α=0.05) concentrations than internal leaves (in some cases the values were 3-fold higher). This study highlights worrying Cd concentrations in the edible parts of the studied vegetables, with concentrations up to 4-fold higher than the threshold. Moreover, it points out two major drawbacks in the Italian and European regulatory frameworks: 1) metal concentration (as total and/or available fraction) limits in agricultural soils are lacking; 2) metal concentration thresholds reported in the CE 629/2008 Regulation, expressed on the fresh weight basis rather than on the dry weight basis, appear not suitable.
High cadmium concentrations in leaves of leafy vegetables
BALDANTONI, Daniela;ALFANI, Anna
2014-01-01
Abstract
Cadmium is a toxic element for all living beings, even at low concentrations, and it is a human carcinogenic according to IARC. Since food is reported as the main source of Cd intake in non-smoking individuals, FAO and WHO set limits for the maximum permitted human intake. Leafy vegetables have a relatively high potential for Cd uptake and translocation, therefore they are often considered Cd accumulators. As they are important salad crops of the Mediterranean diet and are available worldwide, their consumption may represent an effective risk for human health. Lettuce (Lactuca sativa) and endive (Cichorium endivia), grown on different agricultural soils in Campania region (southern Italy), subjected to different fertilisation treatments (unfertilisation, compost amendment and mineral fertilisation), were analysed to clarify if the highest concentrations found are linked to external (older and inedible) or internal (younger and edible) leaves. All the leafy vegetables analysed showed on average 2-fold higher (α=0.05) Cd concentrations in leaves than in roots. Leaf Cd concentrations in both lettuce and endive significantly differed among fertilisation treatments, with values highest in the plants grown on mineral fertilised soils. Apart from the soil fertilisation treatments, however, Cd leaf concentrations were often higher than maximum levels deduced by the CE 629/2008 Regulation. External leaves of endive plants showed significantly higher (α=0.05) concentrations than internal leaves (in some cases the values were 3-fold higher). This study highlights worrying Cd concentrations in the edible parts of the studied vegetables, with concentrations up to 4-fold higher than the threshold. Moreover, it points out two major drawbacks in the Italian and European regulatory frameworks: 1) metal concentration (as total and/or available fraction) limits in agricultural soils are lacking; 2) metal concentration thresholds reported in the CE 629/2008 Regulation, expressed on the fresh weight basis rather than on the dry weight basis, appear not suitable.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
