The tsunami that followed the earthquake on March 11, 2011, destroyed almost all the cities and villages along the serrated coast of northeast Japan. The affected prefectures plan to reconstruct and enlarge a coastal levee to prevent damage from future tsunamis. Since the coastal levee will cover the flat land close to the shore and available land can decrease remarkably in a small fishing village, it is not appropriate to construct a huge coastal levee that could exceed 10 m in height. It is necessary to consider local characteristics such as topography, population, industry, the natural environment, culture, and lifestyle before developing a disaster prevention plan. Moreover, residents, specialists, and the administration should discuss appropriate methods to defend local communities against future tsunamis. The coastal levee is only one means for disaster prevention, and its effective use is predicated on the condition that it does not lead local communities to decline.

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The values for cost per life-year saved (CPLYS) are estimated for the regulations of vegetables and rice contaminated with radioactive caesiums released by the Fukushima daiichi nuclear accident in 2011. The estimation is based on an exposure coefficient, 1.6×10^-8 years of loss of life-expectancy per becquerel of radioactive caesiums, and on the economic values lost by the prohibition of the distribution of contaminated agricultural products. The estimated values for CPLYS are 6.6 to 8.0 million yen and 23 to 51 million yen for the vegetables in March and April respectively, but up to 1.0 billion yen for rice. The latter value is much larger than the value of a life-year saved, which is estimated to be 20 million yen.

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Initial problem formulation and clear description of purpose of risk assessment for decision making and examination of its utility after its implementation in food safety are extremely important, but have not been well recognized in Japan. Examples of problems in current food safety risk assessment and inappropriateness in the actual application of the results of assessment to the risk management are discussed. A new paradigm of risk governance in food safety based on the recent progress in the risk assessment concepts developed by international cooperative efforts, such as works of the International Programme on Chemical Safety (IPCS), and its integration with relevant decision making for risk management together with effective risk communication, are described.

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The national expenditures for countermeasures against major causes of mortality and their effectiveness are not unraveled. In this study, we evaluated relationship between the mortality by major causes and their national expenditures for countermeasures, and then provided information to decide whether their expenditures for countermeasures meet persons' willingness to pay. Whereas the number of deaths by most major causes has been increasing, their age-adjusted mortality rates and age specific (≤64 years old and ≥65 years old) mortality rates showed decreased trends, suggesting that their expenditures for countermeasures have been effective. There were several orders of magnitude differences in expenditures for countermeasures among causes of mortality despite the similar number of deaths. The causes of mortality with high expenditures for countermeasures (e.g. traffic accident and malignant neoplasm) showed large reduction of mortality rates. The expenditures for countermeasures against traffic accident, malignant neoplasm, cardiocirculatory disease and fire disaster were comparable to or lower than the persons' willingness to pay for the risk reduction.

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