110mAg root and foliar uptake in vegetables and its migration in soil

Abstract

110mAg, as a radionuclide of corrosion products in water-cooled nuclear reactors, was detected in the liquid effluents of Guangdong Daya Bay Nuclear Power Station (GNPS) of Daya Bay under normal operation conditions. Experiments on a simulated terrestrial agricultural ecosystem were carried out using the pot experiment approach. The most common plants in Hong Kong and the South China vegetable gardens such as lettuce, Chinese spinach, kale, carrot, pepper, eggplant, bean, flowering cabbage, celery, European onion and cucumber were selected for 110mAg root and foliar uptake tests. The results show that carrot, kale and flowering cabbage have the greatest values of soil to plant transfer factor among the vegetables, while 110mAg can be transferred to Chinese spinach via foliar uptake. Flowering cabbage, the most popular leafy vegetable locally, could be used as a biomonitor for the radioisotope contamination in vegetables. Soil column and adsorption tests were also carried out to study the leaching ability and distribution coefficient (Kd) of 110mAg in the soil. The results show that most of the radionuclide was adsorbed in the top 1 cm of soil regardless of the pH value. The Kd was also determined. © 2002 Elsevier Science Ltd. All rights reserved.