It belatedly came to light that the Japanese government did not disclose the Japan-based U.S. military's assessment that U.S. bases in Okinawa are highly likely to be the source of contamination by a substance feared to be carcinogenic.
According to Kyodo News and the Asahi Shimbun on the 9th, the Japan-based U.S. military told the Japanese government in Dec. 2023 that it was highly likely that the use of foam fire extinguishing agents containing PFAS at firefighting training facilities at Kadena Air Base and Futenma Air Station caused contamination of the surrounding soil.
PFAS does not easily break down in nature and is called the "forever chemical." Concerns have been raised that some substances can cause various diseases, including cancer.
Okinawa Prefecture has demanded on-site inspections inside the bases since 2016, saying PFAS was detected at high concentrations around U.S. military bases.
While judging that the bases are highly likely to be the source of contamination, the Japan-based U.S. military conveyed to the Japanese government that it could not accept Okinawa Prefecture's request for on-site inspections.
Japan's Defense Ministry announced only that the Japan-based U.S. military would not allow on-site inspections. It did not disclose the U.S. military's assessment that Kadena Air Base and Futenma Air Station are highly likely to be sources of PFAS contamination.
Kyodo News reported that language acknowledging the possibility of contamination at U.S. military bases was deleted from the final text during the process of coordinating the announcement wording between the U.S. and Japanese governments.
Okinawa Governor Tamaki Denny criticized the Japanese government's response and stressed, "To resolve the base contamination issue, Okinawa Prefecture must conduct on-site inspections itself." Local residents are also pushing back, saying the Japanese government hid the relevant facts.
Cabinet Spokesperson Minoru Gihara, the Japanese government's spokesperson, said at a regular news conference that day, regarding the specific details discussed by the Japan-based U.S. military and the Japanese government, "I will refrain from answering in consideration of relations with the U.S. side."
Okinawa Prefecture plans to again ask the U.S. military for on-site inspections, saying PFAS was detected not only around Kadena Air Base and Futenma Air Station but also around Camp Hansen in central Okinawa's main island.
The United States and Japan concluded an agreement in 1973 allowing local governments to request on-site inspections or ask the U.S. military to investigate if there are reasonable grounds to suspect contamination occurred within U.S. military facilities.