THE EFFECT OF VARIETY ON HEAVY METALS INTAKE BY ONION GROWN IN CONTAMINATED SOIL

摘要

The environmental study, carried out in Slovak Republic, was aimed at assessment of quality of onion based on the contents of heavy metals (Zn, Cu, Ni, Pb, Cd) as well as the possible correlations among selected heavy metals in soil and onions (Allium cepa L). Seven different varieties were analysed (Sherpa, Boston, Bingo, Shakespeare, Lusy, Vsetana, Radar). Seven sampling sites were selected and the analyses of pHkci , P, K, Mg and chosen heavy metals in 2 different extracts were carried out (aqua regia, 1 M NH_4NO_3). Gained results showed that in some sampling sites the measured values were exceeded in comparison with limit values given by the law no. 220/2004 (valid in the Slovak Republic - SR) as well as threshold values proposed by European Commission (EC) (2006). In our paper the values of total cadmium content were in range from 1.10 to 1.28 mg/kg and the content of mobile form of lead was in range from 0.13 to 0.33 mg/kg. In the case of onion the highest acceptable amounts for cadmium and lead were also exceeded and the values ranged from 0.09 to 0.38 mg/kg and 0.56 to 1.80 mg/kg. Among the varieties statistically significant differences (P < 0.05) in intake of heavy metals were found (Multiple Range Tests for heavy metal by variety, Method: 95.0 percent LSD).