In the present work, Thoron (220Rn) concentrations was determined for (44) samples of medical drugs derived from medicinal plants in Iraqi pharmacies. Solid state nuclear detectors (SSNTDs) CR-39 detectors were used in the present study. The results show that the Thoron concentrations in the samples under study ranged from 1.82 Bq/m3 to 66.48Bq/m3, with an average 32.91±3.36 Bq/m3. All results of radon concentrations for all samples were much less than the acceptable lower limits of the action level, by International Commission on Radiological Protection (ICRP). So, the intake of the studied samples of medical drugs in Iraq does due to 220Rn not lead to substantial changes in the internal effective dose. It is conclude that the thoron concentrations in the samples under study were not significant from a health hazard point of view.
Medical drugs; Medicinal plants; 220Rn concentrations; C-39; Annual internal dose.
The basic component of our life support system is considered to be in the soil, water, plants and air. These environmental components contain measurable amount of radioactivity. The specific metabolic character of the plant species may lead to accumulation of radio -nuclides in their organs, which may further depend upon the physic- chemical characteristics of the soil . Therefore, there may be increased risk to human population via food chain. The primary sources of elements from the environment to plants are: air, water and the soil . The radionuclides present in the environment are transferred to plants by two ways first indirect method uptake from soil through roots. When food crops are grown in the contaminated soil, the activity is shifted from the soil to the roots and then in shoots. At the end, activity is transferred to the human diet . These radio?nuclides can get transferred into plants along with the nutrients during mineral uptake and accumulate in various parts and even reach edible portions . Second, it is direct method absorption through aerial parts of the plants. Presence of radioactivity in plant organs has been reviewed by various workers . There are two pathways leading from Uranium and thorium to parents in plant: through the air and through the roots . The plants roots are naturally related to microorganisms, and these associations can have direct or indirect impacts on the mobility, availability and acquisition of elements by plants . The radiological effect of the uses of fertilizers in soil is due to the internal irradiation of the respiratory organ by the alpha particles, short lived radon thoron progeny and the external irradiation of the body by gamma rays emitted from the radionuclides. Radon is carcinogenic to humans and responsible for main natural radiation exposure to human being [5,6]. Thorium (chemical symbol Th) is naturally-occurring radioactive metal found at very low levels in soil, rocks, and water, and therefore is found in plants and animals as well. The most common form of thorium is 232Th, found naturally.