Japan raised the severity level of the crisis at its crippled nuclear plant Tuesday from 5 to 7 to rank it on par with the 1986 Chernobyl disaster, citing cumulative radiation leaks contaminating the air, tap water, vegetables and seawater.

The new ranking signifies a “major accident” that includes widespread effects on the environment and health, according to the Vienna-based IAEA.

Officials from Japan’s Nuclear and Industrial Safety Agency said that the cumulative amount of radioactive particles released into the atmosphere since the incident had reached levels that apply to a Level 7 incident. Other factors included damage to the plant’s buildings and accumulated radiation levels for its workers.

TEPCO acknowledged that, if leaks continue, the amount of radioactivity released might eventually exceed the amount emitted by Chernobyl.