Documents on the government committee’s website show that of 890,000 tonnes of water held at Fukushima, 750,000 tonnes, or 84 percent, contain higher concentrations of radioactive materials than legal limits allow.
In 65,000 tonnes of treated water, the levels of radioactive materials are more than 100 times government safety levels.
Radioactive readings of one of those isotopes, strontium-90, considered dangerous to human health, were detected at 600,000 becquerels per liter in some tanks, 20,000 times the legal limit.