土砂災害を起因とした化学物質流出事故のリスク評価と対策の費用便益分析

抄録

In Japan, landslides have tended to increase along with an increase of precipitation; therefore, the damage to industrial and economic activities due to landslides should be concerned. However, previous research on Natural-hazard triggered technological accidents (Natech) has not been focused on landslides. Considering such backgrounds, we established a landslide risk assessment method for industrial facilities and conducted the cost-benefit analysis for the countermeasure option. Specifically, we picked up an industrial facility handling chemical substances located in the landslide hazard-prone area and also evaluated the health risk caused by the chemical release accident triggered by the landslide. Here, we selected n-hexane as a target chemical substance and calculated the atmospheric concentration after the accident. We calculated construction costs for countermeasure and accident costs such as compensations under the assumed scenario based on the Acute Exposure Guideline Level. The results showed that compensation for victims accounted for about 97% of the accident costs and efficiency of proactive countermeasures considering the cost-benefit ratio.