A Nankai Trough mega-earthquake with a magnitude of 8 to 9 on the Richter scale is predicted to occur with a probability of 70 to 80% within the next 30 years. Therefore, there are concerns about the risk to the health of residents due to the leakage of hazardous chemical substances from factories and business establishments associated with the earthquake. In this study, we attempted to estimate the stock amount of chemical substances subject to the PRTR Law at factories and business establishments in the area expected to be inundated by the tsunami caused by the earthquake.
It was found that the chemical substance stock in the tsunami inundation area nationwide was 19.5 million tons, accounting for 87.1% of the total stock of the 23 prefectures concerned. In addition, it was found that this amount is equivalent to the amount of chemical substances released for about 93 years in the 23 prefectures concerned.
