Relationship between radioactivity and toxicity in some medicinal plants.

Plants absorb water, nutrients and minerals from the soil through their root. Also, minerals, the radionuclides present in the growing media also are absorbed by plant parts following the same pathway. Consequently, it is important to determine the concentrations of these radionuclides in edible plants to access the associated risk to human health. In the present work, the levels of natural radioactivity and the level of some toxic elements in 17 medicinal plants, commonly used in Egypt, were measured using high-purity germanium gamma spectrometry and atomic absorption, respectively. The investigated plants were sub-grouped according to the edible parts into leave samples (n = 8), roots (n = 3), and seeds (n = 6). Also, the specific activity of both radon and thoron was measured by using alpha emitters registration which is emitted from radon and thoron gases in CR-39 nuclear track detectors. Additionally, the concentration of some toxic elements (Cu, Zn, Cd and, Pb) in six samples of medicinal plants was determined by atomic absorption spectrometry.