The Yomiuri ShimbunThe government intends to expand DNA tests conducted on the remains of war dead to include leg and arm bones, in a bid to identify more Japanese victims of World War II, according to sources.
The Health, Labor and Welfare Ministry has hitherto restricted such tests to teeth. However, in response to growing calls from bereaved families to widen the scope of the tests, the ministry plans to include thigh, arm and other bones in its DNA appraisal methods, the sources said.
DNA tests using bones from hands and feet are common in the United States and South Korea.
At least several hundred sets of remains with no teeth are recovered each year, meaning the expanded tests will increase the potential for identifying these remains.
The ministry started DNA tests on the remains of the war dead in fiscal 2003. The tests were, in principle, conducted on teeth covered in hard enamel, from which it is easy to extract nuclear DNA that can accurately identify an individual even after many years. Arm and leg bones were excluded for reasons including the low probability of getting a sample of this DNA.
However, in places such as Okinawa Prefecture and southern countries and areas, which were the site of ferocious battles, many remains have been found without heads, which had been blown off by bombs or removed due to other reasons. This prompted many bereaved families to push the ministry to adopt testing involving arm and leg bones, as is done overseas.
In light of improvements in DNA testing technology, the ministry went on an inspection tour of the United States in June 2016 to examine the procedures used there. The ministry learned the United States successfully extracted nuclear DNA from about 50 percent of the arm and leg bones it tested. Given that South Korea also conducts DNA appraisals on such bones, the ministry has decided to hear the opinion of a panel of DNA appraisal experts as early as this fiscal year and then make a final decision on tests involving the bones.
According to the ministry, about 2.4 million Japanese military personnel and civilian employees of the military died in Okinawa and overseas during the war. The remains of about 1.27 million have been collected so far. The remains of about 540,000 unidentified war dead have been laid to rest at locations including the Chidorigafuchi National Cemetery in Tokyo, although most were incinerated and DNA samples cannot be taken from them.
The ministry recovered the remains of 1,437 war dead in fiscal 2014, and 1,053 war dead in fiscal 2015. Of them, several hundred sets of remains found each year had no teeth. In preparation for the expansion of the testing program, the ministry has stored — instead of incinerating — 55 sets of remains found since July 2016.
The ministry’s DNA tests have identified the remains of 1,064 people since fiscal 2003. However, 98 percent of them were detainees who had been buried in areas such as Siberia in the former Soviet Union. Just 12 identified sets of remains were from Okinawa and southern countries and areas.
The ministry plans to establish this fiscal year a database containing DNA information from the teeth of about 8,000 war dead. If such information can be gleaned from arm and leg bone tests, it will be added to the database starting next fiscal year.
After the law promoting the collection of the remains of the war dead came into effect in April 2016, the government established a plan to strengthen its DNA testing and recovery operations for remains over a nine-year “concentrated implementation period” that began this fiscal year.Speech