Abstract

To ascertain the level of pollution and the way the heavy metals enter oil crops, soil, and plant samples were taken at different distances from the source of pollution, the Non-Ferrous-Metal Works (NFMW) near Plovdiv (0.5 and 15 km). The contents of the heavy metals in the plant material (roots, stems, leaves, seeds, fruit shell) and sunflower oil and rapeseed oil were determined. The quantitative measurements were carried out with inductively coupled plasma emission spectrometer. Peanuts (Arachis hypogaea L.) were the crop with the highest uptake of heavy metals from the soil, followed by rapeseed (Brassica napus L. a napus), sesame (Sesamum indicum L.), and sunflower (Helianthus annuus L.). The distribution of the heavy metals in the organs of the crops had a selective character that in peanuts decreased in the following order: roots > stems > leaves > fruit shell > seeds, in sunflower—leaves > roots > stems > seeds > fruit shell, and in sesame and rapeseed—leaves > stems > roots > fruit shell > seeds. A clearly distinguished tendency toward a decrease of the contents of heavy metals in oil crops was observed with increasing of the distance away from the NFMW. The quantities of lead (Pb), copper (Cu), and cadmium (Cd) in the rapeseed oil, obtained from rapeseed, grown 0.5 km away from the NFMW, were higher than the accepted maximum permissible concentrations. In the oil from sunflower, grown in the region of the NFMW, the contents of Pb and Cu exceeded about two times the maximum permissible concentration and could be hazardous for the people to consume it. Sunflower and rapeseed could be grown in industrially polluted regions until stage “blossoming” and be used for fodder for the animals.