Mercury Contamination at a Former Factory Site in Hachioji City - June 1998

Mercury Contamination at a Former Factory Site in Hachioji City - June 1998

Serious soil contamination with inorganic mercury was discovered at a former factory site (25,000 square meters in area) in Hachioji City, Tokyo. Mercury that was not properly treated in the wastewater treatment process leaked out and contaminated approximately 6,000 cubic meters of soil. The plant manufactures agricultural chemicals, and the leaked mercury could cause health risks such as neurological disorders, kidney dysfunction, and Minamata disease.

According to Ministry of the Environment standards, special controls are required if the mercury concentration in the soil exceeds 0.5 mg/kg, but specific figures have not been disclosed, and citizens have criticized the lack of transparency of information. The Tokyo Metropolitan Government and the city of Tokyo are required to hold explanatory meetings for residents, promote continuous environmental monitoring, and take prompt action, including providing medical assistance.