Tokyo CNN  — 

After reactors at the Fukushima Daiichi nuclear plant suffered catastrophic meltdowns, thousands of workers were sent in to deal with the aftermath.

Now, more than four years later, Japan has confirmed the first case of cancer related to that dangerous work.

The country’s health ministry said Monday a former Fukushima worker who was diagnosed with leukemia was entitled to workplace compensation.

The unnamed man in his 30s worked at the plant from October 2012 to December 2013, and was exposed to high levels of radiation, the ministry said.

“This is a massive blow to the IAEA, which stated in September of this year that no discernible health effects due to the exposure to radiation released by the accident are to be expected,” Greenpeace said.

IAEA is the International Atomic Energy Agency.

About 45,000 workers have been involved in cleanup work at the Fukushima plant since August 2011. The earthquake that caused the disaster at the facility took place five months earlier, in March 2011.

Ten other former Fukushima workers have filed similar cases. Seven were dropped; three are pending, the ministry said.

Tokyo Electric Power Company, the plant’s operator, said it wasn’t in a position to comment on the case of the worker, who was employed by a subcontractor.

“We would like to offer our sympathy to the former worker,” the company said. “We would like to continue working on the reduction of radiation at the site as well as thoroughly controlling the radiation exposure of the workers.”