For the first time ever, scientists have been able to prove the use of chemical weapons through the analysis of environmental residues taken years after such an attack occurred. In a development that could have far-reaching consequences for the enforcement of the chemical weapons treaty, soil samples taken from bomb craters near a Kurdish village in northern Iraq by a team of forensic scientists have been found to contain trace evidence of nerve gas, GB, also known as Sarin, as well as mustard gas.
The samples were collected on June 10, 1992 by a forensic team assembled by the Boston-based Physicians for Human Rights (PHR) and the New York-based Human Rights Watch (HRW). The samples were forwarded to the Chemical & Biological Defence Establishment (CBDE) of Great Britain’s Ministry of Defence at Porton Down which analyzed them.
Eyewitnesses have said that Iraqi warplanes dropped three clusters each of four bombs on the village of Birjinni on August 25, 1988. Observers recall seeing a plume of black, then yellowish smoke, followed by a not-unpleasant odor similar to fertilizer, and also a smell like rotten garlic. Shortly afterwards, villagers began to have trouble breathing, their eyes watered, their skin blistered, and many vomited - some of whom died. All of these symptoms are consistent with a poison gas attack.
“These scientific results prove beyond a shadow of doubt that the Iraqi government has consistently lied to the world in denying that these attacks occurred,” said PHR and HRW. “They also send a clear signal that chemical weapons attacks cannot be launched in the belief that the natural elements will quickly cover up the evidence.”
According to scientists at Porton Down, the discovery marks “the first time that we have found evidence in soil samples of traces of the degradation products of nerve agent.” In addition to degradation products of nerve agents, the sample also yielded significant amounts of the degradation products of mustard gas.
Alastair Hay, a consultant to PHR and Senior Lecturer in Chemical Pathology at the University of Leeds, said, “This discovery not only confirms eyewitness accounts and medical examinations of Kurdish people that nerve gas as well as mustard gas were used against them, but it also has enormous implications for the effectiveness of the chemical weapons treaty.” While inspection teams from the United Nations Special Commission have found both mustard and nerve agents stored in Iraq, as well as munitions containing them, the samples from Birjinni show they were actually used, Hay said.
In addition to confirming reports of a gas attack on Birjinni, the findings “indicate that samples collected from appropriate locations can provide evidence of the presence of chemical warfare agents over four years after the attack,” according to Dr. Graham Pearson, Director General and Chief Executive of the Chemical and Biological Defense Establishment. “This should contribute to the deterrent effect against nations contemplating the use of chemical weapons.” So far, the Chemical Weapons Convention has been signed by 145 countries and is now awaiting ratification before entering into force.
In August 1988, shortly after the ceasefire that ended the Iran-Iraq war, the government of Saddam Hussein launched a major military offensive against the Kurds in northern Iraq, sending tens of thousands of refugees fleeing into southeastern Turkey. Six weeks later, in October 1988, a PHR medical team interviewed and medically examined dozens of Kurdish refugees who either witnessed or showed physical symptoms of chemical weapons attacks. The PHR team concluded that bombs containing mustard gas and at least one unidentified nerve agent had been dropped on Kurdish villages in northern Iraq.
According to HRW, the Birjinni attack was one of dozens of chemical weapons attacks launched against the Kurds in 1988. “These chemical weapons attacks were part of a genocidal campaign carried out against Kurdish civilians,” said Kenneth Anderson, director of the Arms Project of Human Rights Watch and a member of the PHR/HRW forensic team that visited Iraqi Kurdistan in June 1992.
At least four people were killed during the attack on Birjinni, two in an orchard and and two brothers in a cave where they sought refuge. The remaining villagers fled. Refugees reported that Iraqi soldiers visited the village days later and buried the two victims found in the orchard, and elderly man and a young boy.
On June 10, 1992 a forensic team from PHR/HRW visited Birjinni, a small village of about 30 houses, a mosque, and a school. The team consisted of Dr. Clyde Snow, a well known consultant in forensic anthropology to medical examiners’ offices in the United States and professor of anthropology at the University of Oklahoma; James Briscoe, an archaeologist with Roberts/Schornik & Associates, Inc., Norman, Oklahoma; Mercedes Doretti and Luis Fondebrider, both members of the Argentine Forensic Anthropology Team; Kenneth Anderson, a consultant to PHR and HRW; Isabel M. Reveco of the Chilean Forensic Anthropology Team; and Stefan Schmitt of the Guatemalan Forensic Anthropology Team.
The forensic team exhumed the bodies of the man and boy reportedly killed during the attack and buried by the Iraqi soldiers. Anthropological evidence showed the man to be about 60 years of age and the boy to be about five years of age. Neither skeleton showed signs of physical trauma. The forensic team took samples of clothing and soil and insect larva from the graves. They also took soil samples and pieces of metal from inside four bomb craters located just about 700 meters from the village. The craters were found in a line, each crater about 30 meters apart. Three samples were taken from each crater: one each from the center and southern and northern edges. The samples were secured in plastic bags, described, and labelled. The team also observed bomb fragments in and around the craters.
At Porton Down, analysis by gas chromatography and mass spectrometry found that six soil samples taken from the first two craters contained mustard agent and/or thiodiglycol, a compound produced by the hydrolysis (breakdown by water) of mustard agent. Trace amounts of the degradation products of sulfur mustard, 1,4-thioxane and 1,4-dithiane, were also detected in these samples. The chemists at Porton Down also found the presence of the compound tetryl, an explosive that, according to Dr. Hay, is widely used in chemical munitions.
The second six samples, including pieces of metal, countained “unequivocal” residues of methylphosphonic acid (MPA) and isopropyl methylphosphonic acid (iPMPA), according to analytical chemists at Porton Down. MPA is a product of the hydrolysis of any of several chemical weapons nerve agents. iPMPA is a product of the hydrolysis of the nerve agent GB, which is made using isopropyl alcohol. The compounds could only have come from a nerve gas, and iPMPA is a unique fingerprint of GB.
No traces of mustard or nerve agents or their breakdown products were found in the samples taken from the gravesites, although only about three grams of clothing were examined. Further analyses of these are planned.
According to the analysis team at Porton Down, “this is the first example, to our knowledge, that a suspected use of nerve agent had been corroborated by the analysis of environmental residues. The analyses also demonstrated that traces of chemical weapons agents or their degradation products can still be detected in the environment over four years later, provided that the samples are taken from a point of high initial contamination.”
Chain of Custody of Birjinni Samples
- On June 10, 1992, the PHR/HRW forensic team archaeologist Mr. James Briscoe gathered the samples from the craters in Birjinni. While still in Birjinni, Mr. Bricoe placed them in plastic bags marked with Chicago Police Forensic labels and labelled them. Later that day, Mr. Briscoe gave the samples to Dr. Clyde Collins Snow, the team’s forensic anthropologist. The samples remained in Dr. Snow’s custody until he gave them to another team member, Mr. Kenneth Anderson, on June 20, 1992. At no time were the samples unpacked.
- On June 20, 1992, Mr. Anderson packed the samples in his luggage and they travelled with him from Dohuk, Iraq to Istanbul, Turkey. At no time were the samples unpacked.
- On June 22, 1992, Mr. Anderson flew with the samples in his luggage to New York, NY, arriving on the same day. In New York, Mr. Anderson took the samples from his luggage, and kept them at the offices of Human Rights Watch in New York in a sealed box.
- On June 26, 1992, Mr. Anderson sent the samples by Federal Express to Dr. Snow in Norman, Oklahoma. Mr. Anderson did not unpack the samples from their plastic containers at any time.
- On July 13, 1992, Dr. Snow sent the samples by Federal Express to Ms. Susannah Sirkin at Physicians for Human Rights in Boston, Massachusetts. No unpacking of the samples took place.
- On July 16, 1992, Ms. Sirkin sent the samples by Federal Express to Dr. Alastair Hay at the University of Leeds in Great Britain. The samples remained in his custody at the Department of Chemical Pathology, University of Leeds. No unpacking of the samples took place. In the meantime, Dr. Hay contacted the Chemical & Biological Defence Establishment (CBDE) at the Ministry of Defence in Porton Down.
- On October 2, 1992, when the CBDE gave the final clearance for the samples to be analyzed, Dr. Hay sent the samples by Securidor Omega Express to the CBDE in Porton Down.
- On October 5, 1992, Securidor Omega Express delivered the package containing the samples to CBDE. CBDE superintendent Mary C. French placed the package in a locked refrigerator, where they remained in the queue of samples to be analyzed.
- On February 2, 1993, Dr. Robin Black at the CBDE opened the samples for analysis.
