History of health management for radiation accident and disaster

According to the chronological evidences of radiation accident and disaster in the world, we can easily learn the valuable lessons on radiation health effects and also a necessity of well preparatory and organized system and network of emergency radiation medicine. Especially countermeasures on emergency radiation medicine have been categorized simply into two groups: acute and chronic effects, and high-dose and low-dose consequences. Based on the identification of potential impacts on radiation health and environmental effects, referring the past accidents and disasters, comprehensive risk analysis including risk estimation, risk management and risk communication is really required for maintaining healthy lives and safeguards in the unavoidable nuclear age of the 21st century.