Tap water might have been contaminated

In April, Professor emeritus Akio Koizumi and Associate Professor Koji Harada at the Graduate School of Medicine, Kyoto University, tested the blood of citizens of Ginowan City’s Oyama district for perfluorooctanesulfonic acid (PFOS), an organic fluorine compound. The substance is a suspected carcinogen. The test detected in the citizens’ blood concentrations of PFOS four times higher than the national average, sources informed Ryukyu Shimpo on May 16. The substance is found in high concentrations in rivers near the U.S. military Kadena base and Futenma airfield, which are suspected sources of pollution. The test also checked the blood for another organic fluorine compound, perfluorohexane sulfonic acid (PFHxS). The test detected in the citizens’ blood a concentration 53 times the national average. As it has been pointed out that PFHxS may affect the cholesterol level and  liver function, the international community is discussing its regulation. (Abridged)