To Answer Cremation Questions, Forensics Finds Unlikely Ally In Physics

November 1, 2000

GAINESVILLE, Fla. — University of Florida physicists and forensic scientists are using the powerful tools of particle physics to solve some of the mysteries of the dead.

In an unlikely collaboration, a group of UF physicists and forensic scientists have demonstrated they can use a particle accelerator to determine whether ashes or ash look-alikes are the cremated remains of people. Although it hasn’t been tested yet, the process also may be able to identify a person based on his or her ashes.

The process is expected to play a role in resolving an escalating number of disputes nationally over so-called “cremains” among families or between families and crematories. Such disputes, which may involve crematories giving the wrong remains to survivors, are becoming increasingly common as more people choose cremation over traditional burial.

“It’s a hot topic, and this opens up a new set of possibilities,” said Michael Warren, an assistant professor in UF’s department of anthropology.

Warren and Tony Falsetti, an associate professor of anthropology and co-director of UF’s William R. Maples Center for Forensic Medicine, sought the physicists’ assistance as part of their work as expert witnesses in a legal battle in South Florida.

Two family members were fighting over the cremated remains of a loved one. One gave the other an urn, but he suspected its brownish-white contents were not what they appeared and turned to UF for help.

Traditional cremations leave behind small bone fragments that forensic workers can readily identify as human bone. But new technology, being implemented at crematories around the country, has resulted in much finer remains with no recognizable bone or human structure. Because cremation destroys all DNA, the new technology is leaving forensic scientists with no ability to separate cremated remains from sand, for example.

“The latest cremation technology kind of put us out of business,” Warren said.

Enter the physicists. Gene Dunnam and Henri Van Rinsvelt, both UF physics professors, and Ivan Kravchenko, a senior engineering technician, knew particle accelerators had been used before to discover trace elements in geological samples. They decided to try using a process known as Particle Induced X-ray Emission analysis, or PIXE, with the disputed remains.

Although an older model was used for the initial experiment, the Los Alamos National Laboratory recently donated a newer accelerator to UF. Housed in a large basement room in the new physics building, the accelerator has a 12-foot cylinder connected to a series of smaller tubes and chambers. The chamber is charged with 1.7 million volts, which accelerates hydrogen ions and transforms them into a proton beam. The beam is focused on a sample, which sends off X-rays that identify the elements it contains.

The physicists’ experiment showed that the ashes from the South Florida family contained calcium, which would be consistent with human bone. But it also showed that the ashes did not contain phosphorous, another prominent ingredient in bone.

The physicist’s conclusion: The urns did not contain human remains.

“We think it’s a mixture of sandy soil with a little lime rock,” Dunnam said. “Whoever did this was not entirely stupid, because lime rock contains calcium, which is also in bone.”

In certain circumstances, the technique may open a door for forensic scientists to identify individuals based on their remains, Falsetti and Warren said.

For example, if the deceased had recently undergone medical work involving ingesting, say, barium, the particle accelerator would identify that element. If a person had a metal implant, the particle accelerator also would pick up trace concentrations of the metal, even if the visible metal lumps were removed following the cremation.

Falsetti and Warren said demand for identifying cremated remains is on the upswing because of mistakes made during cremations, which are becoming more and more popular nationally. In 1999, about 25 percent of deaths led to cremations, compared with about 20 percent in 1994, according to the Cremation Association of North America. With 71,739 cremations, Florida trailed only California among states with the most cremations.

“Not a lot of labs do cremains analysis, but the fact that we’re at a major university and can develop new techniques with physicists or other experts here really sets us apart from those that do,” Warren said.