Heavy metals in medicinal and fodder plants of the negev desert

The concentrations of heavy metals (zinc, copper, iron, manganese, cadmium, lead and nickel) were measured in 51 desert plants, of which 42 are considered medicinal, three fodder and six common plant species. Accumulation of certain heavy metals in some plant species was 2 - 260-fold higher than the available heavy metal content of the soil of the Negev desert. The highest levels of heavy metal (mg kg^-1 dry weight) were: Fe: 3020 in Gundelia tournefortii and 2485 in Anchusa strigosa; Cu: 27 and 21 in Nicotiana glauca and Anchusa strigosa, respectively; Zn: 113 and 85 in Populous euphratica and Achillea fragrantissima, respectively; Mn: 109 and 99 in Phagnolon rupestre and Anchusa strigosa, respectively; Cd: 22 in Achillea fragrantissima; Pb: 33 in Asparagus aphyllus, 25 in Echinops polyceras, and 23 in Seriphidium sieberi; Ni: 19 and 16 in Paronychia argentea and Anchusa strigosa, respectively. The accumulation of heavy metals in some desert plants may open a new perspective for application of these species as 'accumulators' of heavy metals to clean-up contaminated soils in arid environments.