In the wake of the massive tsunami last December that slammed into shores on Thailand and other parts of southern Asia, killing more than 200,000 people, scientists face a disturbing test of the effectiveness of DNA technology in identifying bodies. In Thailand, for example, where about 6,000 bodies were recovered, officials set out immediately to use DNA matching. Yet only a small fraction of the victims have been identified that way. The experience stands in sharp contrast to previous efforts using DNA after mass casualties. It also presages what workers will confront in identifying the dead in hurricane Katrina's aftermath.
Here's a typical story: Thaksin Jitjun, a middle-aged boat-engine salesman from the Thai fishing village of Ban Nam Ken, lost his wife, daughter, son-in-law, and two grandchildren to the tsunami. Like many others, Jitjun gave the police DNA samples, including blood, along with his family's dental and medical records. Five months later, he was able to bury just one relative, his son-in-law, a Frenchman who lived in Thailand. Jitjun's Thai family members are still missing. "I don't have much hope anymore," he says.
About 1,500 unknown bodies still lie refrigerated in containers at mortuaries in southern Thailand. Nearly all those named so far have been matched with dental records and fingerprint examinations. DNA matching has accounted for only about 5 percent of identifications. By contrast, DNA samples helped identify more than 8,000 war dead in the Balkans and more than half those who died in the 9/11 attacks.
"We've experienced more difficulty than anticipated in obtaining postmortem DNA profiles from deceased victims," said Karl Kent, former joint chief of staff for the Thailand Tsunami Victim Identification Center. Although the samples were taken soon after the victims died, the level of DNA degradation was high. Some scientists speculate that high temperatures and high humidity contributed to the breakdown of the genetic material. Arguments have been raised about whether the ocean water in which many of the bodies were immersed preserved or broke down DNA.
In some cases, entire families perished, leaving no one to provide reference samples and information. Also, many victims are thought to have been migrant workers from Myanmar (formerly known as Burma). That country has not participated in the identification effort. Myanmar migrants in Thailand are often reluctant to deal with Thai officials. Only seven bodies from Myanmar have been identified.
The vast majority of those identified by the Victim Identification Center are Europeans, like Jitjun's son-in-law. Fewer than 400 are Thai. That is partly because soon after the tsunami struck, disaster-victim identification teams raced to Thailand from more than two dozen countries and worked independently from Thai scientists to identify foreigners. "They tried to identify their own, their own countrymen," says Barbara Butcher, director of investigations at the New York City medical examiner's office. "There's something very wrong about saying, 'Well, we're going to identify Western but not Eastern bodies.' "
The teams eventually agreed to work together and treat all bodies equally, but the separate systems, and the data collected in the first days, have yet to be fully integrated. Because hundreds of thousands of families throughout the tsunami-ravaged region still lack information on the fate of their loved ones, Butcher and others have called for a better international system and ethical guidelines for responding to mass fatalities.
Official measurements of the earthquake that caused the Asian tsunami are available at http://earthquake.usgs.gov/eqinthenews/2004/usslav.
Visit Interpol's tsunami Web site: www.interpol.int/Public/asiandisaster/default.asp.