Poisoned mongooses in Okinawa

Japanese researchers have detected high levels of polychlorinated biphenyls (PCBs) in mongooses found near two U.S. military bases in Okinawa. PCBs are one of the most toxic chemical waste categories on the planet, with strong persistence in the environment and high resistance to biodegradation. PCBs have been shown to cause cancer in animals and to lead to cancer in humans as well. Research must be undertaken to determine why high levels of PCBs were found near U.S. military bases.

The team of researchers from Ehime University and Meio University found a high average level of PCBs throughout the animals’ bodies and much higher levels of PCBs in their livers. Those levels are said to be much higher than in other parts of Okinawa or in other animals such as cats, boars or raccoons found elsewhere in Japan.

Mongooses were chosen for the study because they have a relatively narrow range of movement and often live close to residential areas. The PCBs they soaked up are highly soluble in fats and can easily accumulate in all types of organisms, with those at the highest levels of the food chain most affected.

In that sense, the mongooses serve as a possible marker of extremely high levels of PCBs in the area around the bases.

As the mongooses were found near U.S. Marine Corps Air Station Futenma and the Makiminato Service Area (Camp Kinser) on Okinawa Island in 2008, the most likely PCB source is equipment on the U.S. bases.

PCBs were widely used in insulators, transformers, capacitors and appliances such as TV sets and refrigerators and electric motors until the United States banned PCB use in 1979.

PCBs are associated with dioxins, another category of highly dangerous pollutant. One type of dioxin is Agent Orange, which reports in The Japan Times and other newspapers have said are stored on U.S. bases in Okinawa. The link has not been established, but it should be investigated.

The mongoose study is one of the first clear indicators that persistent organic pollutants are present near U.S. bases in Okinawa. Because of the secrecy surrounding the U.S. bases, it is not clear whether those toxic chemicals were cleaned up on bases in Okinawa or not.

Further studies are necessary to determine the extent of the pollution. The U.S. military should tell what they know about such pollutants and work with Japanese researchers to ensure that the environment in Okinawa can be kept free from carcinogenic, toxic chemicals.