Scientist says nerve gas nastier than you thought

A new academic study has suggested that US troops may have been physiologically affected by exposure to low levels of sarin nerve gas in the aftermath of the 1991 Gulf War.

It is believed that US soldiers occupying an Iraqi munitions depot at Khamisiyah mistakenly blew up a stockpile of gas rockets in March 1991, believing them to be ordinary explosive munitions. Nobody noticed any ill effects at the time.

It was only two months later, when Iraqi chemical weapons facilities were inspected by the UN as part of the ceasefire agreement, that the US began to realise that nerve gases might have been released into the atmosphere.

There has been no suggestion that any military personnel were exposed to concentrations of sarin high enough to produce immediately noticeable effects. However, meteorological models indicate that 100,000 American troops could have been exposed to very low sarin levels.

This possible low-level sarin exposure has been seen by many as a possible cause of Gulf War Syndrome. If it is, however, it can't be the only one: 150,000 US veterans are still listed as sufferers.

Dr Roberta F White led this latest research effort, the results of which are to be published in June's NeuroToxicology journal. An abstract of the study can be seen here. Thirteen soldiers who were in the presumed sarin footprint were compared with thirteen who weren't by imaging their brains with MRI scanners.

According to Dr White and her team, the brain scans showed "a significant association between higher levels of estimated sarin/cyclosarin exposure and both reduced white matter...and increased right lateral ventricle...and left lateral ventricle volumes."

The researchers conclude that "these findings suggest subtle but persistent central nervous system pathology in Gulf War veterans potentially exposed to low levels of sarin/cyclosarin".

Dr White has a long history of research in chemical weapons exposure and Gulf War Illness issues.

In 2001, she published research concluding that Gulf War veterans who said they had been exposed to chemical warfare agents showed "poorer performance on cognitive tests involving specific functional domains".

In 2004, she worked on a project examining 18 people exposed to sarin during the Tokyo subway gas attack of 1995, and concluded that sarin may have unknown, long-term chemical neurotoxic effects other than those already understood. That paper specifically rejected the idea that post-traumatic stress disorder might be involved.

In 2003, Dr White was reported in the Veterans' Administration newsletter (pdf) as having done another study which "found Gulf War-deployed vets performed 'significantly worse' on tests of attention, visuospatial skills, visual memory, and mood. The study also found veterans who took the anti-nerve agent pills pyridostigmine bromide during the war performed worse than those who didn't take the drug".

Generally speaking, Dr White seems to be a good scientist to go to if you want a positive result.

It's perhaps also worth noting that declassified CIA reports suggest that some or all the sarin rounds blown up at Khamisiyah were of binary construction, meaning that they contained not sarin but two precursor chemicals which would be mixed to form sarin when the weapons were fired. Blowing up kit like this wouldn't release large amounts of nerve agent into the atmosphere; just precursors.

If the rockets weren't binaries, there would be an excellent chance of their sarin payload having decomposed to uselessness. This was a major problem for the pre-1991 Iraqi chemical weapons industry.

Still, it's always possible that sarin has some kind of serious long-term effects beyond those documented, at very low concentrations. If that does turn out to be the case, given the huge quantities of sarin released during the Iran-Iraq war of 1980s, one might expect visible symptoms in those countries' populations.

Or, it could be that this is the kind of problem which only affects Western society, and as long as there are compensation payouts and research funding to be had, people will pursue them. ®

Lewis Page is a former bomb-disposal operator with experience in handling live chemical weapons.