A civic group says blood tests it conducted on people living near US military bases in Okinawa have detected two to four times Japan's national average level of widely used chemical compounds known collectively as PFAS, or poly-fluorinated alkyl substances.

Many of the compounds are described as toxic.

The group on Saturday released the test results of blood samples collected from 387 people in six municipalities in Okinawa Prefecture.

The tests were conducted with the help of Kyoto University following a series of reports on the compounds being detected in high concentrations in rivers and spring water near US military bases in the prefecture.

The group says the test detected 3.8 times the nationwide average level of PFAS in the town of Kin, which hosts Camp Hansen.

Three point seven times the average level were detected in Chatan town, home to the Kadena Air Base and other US military facilities, and 3.4 times in the Kiyuna district of Ginowan City with the Futenma Air Station.

The government recorded the average figure last year.
Japan does not have legislation that sets criteria for PFAS levels in blood.

The group says that based on the test results, it plans to urge the central and prefectural governments to conduct larger-scale tests to clarify the facts about the situation concerning PFAS.

The Okinawa Prefectural government has already asked the US military to allow it to conduct investigations on US bases to check whether the fluorine compound leaked from them.

But the US military has not allowed such probes to be conducted.