The U.S. government Friday filed its final report on the submarine USS Houston's radioactive leak earlier this year, saying it had no adverse effect on human health or the environment, the Foreign Ministry said.

The incident came to light on Aug. 1 when the United States notified Japan that the Los Angeles-class fast-attack sub may have leaked radioactive water during port calls at Nagasaki, Kanagawa and Okinawa prefectures.

Friday's report submitted by the U.S. Embassy's deputy chief of mission, James Zumwalt, concluded that the leak of a total potential amount of 0.605 microcuries was due to water seeping out of a shut valve.