HIROSHIMA – Children of Hiroshima A-bomb survivors sued the central government on Friday, claiming Tokyo has denied them their constitutional right to pursue happiness by failing to provide financial support.

In what the plaintiffs say is the first lawsuit in Japan to address the impact radiation has had on the children of the hibakusha, they are demanding that the Atomic Bomb Survivors’ Assistance Law be changed so that second-generation hibakusha can also be covered by it.

Arguing that their parents’ exposure to radiation from the 1945 U.S. atomic bombing of Hiroshima affected their own health as well, the 22 second-generation hibakusha are demanding the government pay them ¥100,000 each in compensation.

The government provides qualified first-generation survivors with various forms of financial assistance and covers the full cost of their medical expenses, but the aid does not extend to their children.

The plaintiffs argue that although the government rejects the hereditary effects of the atomic bombing on the children of survivors, the possibility of such effects cannot be ruled out as some studies do recognize them.

They also say the government has a responsibility to qualify them for support because they are living under constant fear that they may someday develop a radiation-linked disease.

“It is a historic first step,” Noboru Sakiyama, head of a national association of second-generation hibakusha groups, said in a news conference after filing the lawsuit.

“Through the trial we will seek support for second-generation hibakusha,” he said.

Plaintiff Katsuhiro Hirano, 58, has always been worried about his health because he knows several second-generation hibakusha who developed cancer and leukemia when they were young.

“Every time I became sick, I was worried that it may be having something to do with” being the son of a hibakusha, Hirano said.

Hirano’s mother got exposed to radiation when she came to look for her younger sister in the city two days after it was destroyed by the bomb on Aug. 6, 1945.

To pressure the government into granting them financial aid, second-generation hibakusha founded a group in the 1970s but to no avail.

The Health, Labor and Welfare Ministry has declined to comment, saying it has not seen the complaint yet.

A similar lawsuit is expected to be filed Monday by the children of those who survived the Aug. 9, 1945, U.S. atomic bombing of Nagasaki.