An expert, left, collects soil samples at Futenma No. On August 15. 2 Elementary School in Ginowan, Okinawa Prefecture. The school is next to the U.S. Marine Corps Air Station Futenma. Mika Kuniyoshi GINOWAN, Okinawa Prefecture - Extremely high levels of a suspected carcinogen were detected in the grounds of an elementary school next to the U.S. Marine Corps Air Station Futenma, rekindling persistent health concerns over the handling of dangerous chemicals at U.S. military bases.
A reading of perfluorooctane sulfonic acid PFOS at one site of the Futenma NoFutenma No. 2 Elementary School was about 29 times higher than the PFOS levels deemed under U.S. environmental guidelines to carry risks in containing the contamination.
Koji Harada, an associate professor of health and environmental sciences at Kyoto University, expressed alarm over the findings, saying they underlined the need for on-site inspections at the Futenma airfield.
The findings showed extremely high levels of the PFOS even on the ground surface where the contaminant tends to be washed away by rainwater, he said. The only way to address the problem is to open an investigation to find out the source of the contamination, given the high likelihood that soil lying deeper from the surface is polluted along with the groundwater. Near the school premises is a waste pipe that is believed to originate in the Futenma base.
An expert organization commissioned by a civic group called Ginowan Churamizu Kai society working to maintain clean water in Ginowan went ahead with an investigation of its own, saying it suspected that wastewater containing PFOS was released through the pipe.
On Aug. 15, the school's experts collected soil samples several centimeters below the ground surface at three sites on the school premises to determine the presence of PFOS. The findings were announced on Sept. 5.
After receiving its report, the municipal education board notified parents and other concerned parties on Sept. 7 that children will be prohibited from entering the area where figures are high.
Water quality guidelines for drinking and river water in Japan restrict the presence of PFOS and other substances to less than 50 nanograms per liter of water as the preliminary limit.
The soil screening guidance from the Environmental Protection Agency sets 38 nanograms per kilogram of soil as a level that requires more detailed examination for safety assessment.
The researchers found readings of 1,100 nanograms at one site.
A reading of 700 nanograms, about 18 times the U.S. level, was found at a second site. The gauge did not show a specific figure, because the level was so low at a third site.
PFOS do not degrade in the natural environment and pose a threat to humans and ecosystems.
The chemical is widely used in military bases as well as the petrochemical industry as firefighting foam to quell fuel fires.
The use and production of PFOS was banned in Japan in 2010 in principle.
Since 2016 a flurry of reports have emerged in Okinawa Prefecture about high concentrations of the chemical in rivers and other sites near U.S. military installations.
The prefectural government believes that U.S. military facilities are the source of the contamination.
Despite repeated requests under the Japan-U, the Japanese government and authorities in the southernmost prefecture have been denied access to the bases to carry out studies of their own. Status of Forces Agreement.
The safety cones were placed at the sites where high levels of PFOS were detected to keep children away from the city. The children were told to wash their hands and gargle carefully after playing in the school grounds.