A man who worked at the Fukushima nuclear plant has contracted cancer due to radiation exposure, Japanese officials said on Tuesday. The worker, who is currently in his 40s, reportedly installed covers over damaged plant reactors from October 2012 to December 2013, during the cleanup phase after a major tsunami crippled the plant.

"This person went to see a doctor because he was not feeling well. That was when he was diagnosed with leukemia," said a health ministry official during a press briefing on condition of anonymity. He added that other possible reasons for the man's diagnosis had already been dismissed.

The Health and Labor Ministry also said that the government will compensate the man for medical costs and lost income, but did not give an exact amount.

Due to his previous work at numerous other nuclear plants, medical experts could not easily determine whether working at Fukushima directly caused his cancer. The anonymous official, however, reported that out of the man's total radiation exposure of 19.8 millisieverts, he received a dose of 15.7 millisieverts during his time at Fukushima.

'Massive blow' to policy

The announcement comes just a few days after Japan's decision to reactivate a second nuclear reactor. Future cancer cases could be on the horizon, since the worker's radiation exposure was far below the recognized limit for nuclear workers.

"This is a massive blow to the IAEA (International Atomic Energy Agency), which stated in September this year that no discernible health effects are to be expected due to the exposure of radiation released by the accident," said the environmental organization Greenpeace.

Ten other health compensation cases have been filed with the government since the Fukushima disaster, with seven rejected and three still under consideration.

rs/msh (AP, AFP, Reuters)