Keywords: 
• radioactive contamination /
• drinking water /
• health risk /
• accident

Abstract: The potential health risk caused by transporting of radioactive material is increasing with the fast development of nuclear energy and nuclear technology. In present paper, the contamination of cesium-137, cobalt-60 and strontium-90 to the Yellow River of Lanzhou region was considered and the dispersion of these radionuclides were modeled. Furthermore, the potential health risk brought out by the radionuclide dispersion to drinking water were discussed. Based on the existing domestic activity of the radionuclide sources and the data obtained from the international radioactive accidents, the activity levels and flow rates of cesium-137 was presented with consideration of the effect brought out by the sediment. The potential health risk of cesium-137 at two different drinking water sources, which were 64 km and 114 km from the accident position in the river downstream, were calculated, respectively. The mortality risk and morbid risk coefficients of cesium-137 were obtained and used to evaluate its health risk induced by ingestion of tap water. At the same time, the potential health rick of cobalt-60 and strontium-90 were also assessed by using the minimum average flow rate of the Yellow River during the nearest past 30 years. All the results showed that the dispersion of cesium-137, cobalt-60 and strontium-90 in the Yellow River varied with the radioactivity of the nuclides, the flow rate of the river and suspended sediment in the river, and ingestion of tap water contaminated by these radionuclides will cause mortality and morbid risk. Hence, it is very important to react promptly to the river drinking water contamination caused by radionuclides so as to reduce their health risk to human beings.