特集：アジアの資源開発におけるガバナンスのあり方―市場経済移行国における現状と今後の課題
リスク評価研究はリスクガバナンスにどのように活かされるか?
中国における鉛のリスク評価を事例として
2015 年 60 巻 3 号 p. 88-99
詳細
2015 年 60 巻 3 号 p. 88-99
A risk assessment (RA) is a series of procedure to quantify magnitude of risk. For an effective and transparent risk governance, sharing and understanding on quantitative risk information would be a first step. It is necessary not only for cases in developed countries but in developing countries. In this article, the author referred to a definition of the word “risk,” and introduced methods of RA in chemical risk. On chemical substances, risk is calculated according to the following formula;
Risk=Hazard×Exposure
Hazard assessment is a process of judgment whether the substance causes an adverse effect or not.Exposure assessment is a quantification procedure on exposures for targeted people who are currently experiencing or anticipating the adverse effect. For those assessments, scientific knowledge and data are used, such as animal test data, epidemiological data, measured concentration(s) for environmental media and concentration(s) appropriately estimated by mathematical models. For decision making in the real world, we should consider economic, social, political consequences of regulatory options in addition to the results of RA. This step is not necessarily scientific.
Then the author introduces an example of RA, focusing on lead pollution in a waste processing site for used/waste electronic equipments (E-waste) of China. Guiyu, which is located in Guangdong Province, was heavily polluted by inappropriate E-waste recycling, and well known for its bad condition. Researchers surveyed environmental concentrations and adverse effects on the residents in Guiyu. In our study, we confirmed whether model estimation on environmental concentration by a simple multi-media model is valid for exposure assessment and risk assessment. The model simulation to estimate lead concentration was applied by the model named USES-LCA 2.0. The result showed a good agreement on the simulated concentrations and measured concentrations. This suggests that risk assessment based on a model simulation will be expanded to prioritize plural scenarios on environmental management policies. A transparent prioritization tool of environmental management policies, based on the consideration of the cost-effectiveness of risk reduction, will facilitate better decision making.
