The health ministry Tuesday certified a man with leukemia as having suffered an industrial accident and being entitled to benefits after he was exposed to radiation as a construction worker at the Fukushima No. 1 nuclear plant, though it did not confirm there was a link between the radiation and the cancer.

The man, now in his early 40s, is the first person involved with working at stricken facility to receive the certification for developing leukemia.

He installed covers for the damaged reactor buildings at the plant between October 2012 and December 2013 before being diagnosed with leukemia, according to the ministry. He developed the disease while in his 30s.

"While the causal link between his exposure to radiation and his illness is unclear, we certified him from the standpoint of worker compensation," an official of the Health, Labor and Welfare Ministry said.

Workers who are injured or become ill due to work or commuting can receive benefits under Industrial Accident Compensation Insurance. To receive compensation, they must submit claims to a labor standards inspection office, which will examine and pass judgment on them.

For leukemia to be certified as an industrial accident caused by radiation exposure, a claimant must meet certain requirements, such as being exposed to radiation of at least 5 millisieverts in a year, and having developed the illness more than a year after they were first exposed to radiation.

In the aftermath of the nuclear disaster, Tokyo Electric Power Co. installed covers over the damaged reactor buildings to prevent the further dispersal of radioactive material.