The Japanese government concealed the U.S. military’s acknowledgement in 2023 that two of its bases were likely sources of PFAS contamination in Okinawa Prefecture, sources said.
Okinawa Prefecture had requested permission from the U.S. military to conduct on-site inspections of bases to identify the sources of pollution.
The United States rejected the request. But it did acknowledge to the Japanese central government that PFAS contamination in the prefecture likely came from the Kadena Air Base and the Marine Corps Air Station Futenma, the sources said.
However, the Japanese government failed to include that acknowledgment when it released the U.S. response to the public, the sources said.
Asked about Japan’s exchanges with the U.S. side concerning PFAS in Okinawa Prefecture, Chief Cabinet Secretary Minoru Kihara declined to discuss details at his Sept. 8 news conference.
He only said the U.S. response was what “the Defense Ministry has presented to the prefectural government.”
PFAS, a group of chemicals linked to cancer, has been detected at high concentrations around several U.S. military facilities in the southernmost island prefecture. They are called “forever chemicals” because of their extreme durability.
Surveys conducted by the Okinawa prefectural government since 2016 have repeatedly found elevated PFAS levels around the Kadena and Futenma bases.
The prefecture suspected the long-term use of PFAS-containing firefighting foam at the facilities caused the pollution, and it sought to inspect the bases to determine the cause.
According to the sources, the U.S. military told the Japanese government in December 2023 that firefighting foam containing PFAS used in training facilities at the Kadena and Futenma bases was likely responsible for the contamination.
When the Defense Ministry released the U.S. response in December 2025, it disclosed the reasons why the United States denied the prefecture’s inspection request.
But it did not reveal that the U.S. military had identified the two bases as likely sources of the contamination, the sources said.
The U.S. side said access to the bases could be granted only if sampling data clearly showed the contamination originated from U.S. military facilities, and if both governments had agreed standards for evaluating the results.
It said Okinawa’s request failed to meet those requirements.
AloJapan.com