Sarin Exposure Linked to Brain Damage
Click
Here to Add Comment Subject:
Sarin Exposure Linked to Brain Damage
Date:
Sat, 21 Dec 2002 16:51:26 -0500
From:
Stephen Tvedten <steve@getipm.com>
Organization: Get Set Inc. (www.getipm.com)
To: Paul Helliker <phelliker@cdpr.ca.gov>
Director, State of California, Department of Pesticide
Regulation
cc: Christine Whitman whitman.christine@epa.gov
Sarin Exposure Linked to Brain Damage
Debbie Funk Army Times
http://www.armytimes.com
... New scientific research shows low-dose sarin chemical warfare agent exposure, without symptoms at the time of exposure, have long-term health effects; Gulf War veterans' fears confirmed ...
Repeated exposure to the nerve agent sarin at low doses may create lasting effects on the body's systems that influence behavior, according to a study presented at a recent scientific meeting.
In the study, conducted by the Army's chemical defense institute, guinea pigs given two-fifths of a lethal dose of sarin showed higher levels of activity 100 days after exposure compared to animals given a lower dose or no sarin at all.
Moreover, animals injected with sarin at either one-fifth or two-fifths the lethal dose rose on their hind legs more often than did guinea pigs receiving only saline shots.
The differences didn't appear until 100 days after injection. By then, the level of cholinesterase - an enzyme essential for turning off nerve impulses that make muscles contract, salivary glands excrete and other functions - had returned to normal. Sarin inhibits the enzyme and did so initially in the injection phase of the study.
"The results suggest that depression of cholinesterase activity following low-dose sarin exposure may lead to persistent neurochemical or pathological changes that influence behavior," according to an abstract of the study presented Nov. 3 at a meeting in Florida of the Society for Neuroscience.
This study is believed to be the first that has looked at the potential impact over this much time, a researcher said.
Researchers are trying to replicate their work with sarin to validate the findings. They also will test VX, a more persistent nerve agent. "We're trying to pin down whether this is a real effect or not," John McDonough, one of the researchers, said. "We did it very carefully but we want to be absolutely sure we're actually seeing something here."
The levels of nerve agent used in the experiments would trigger alarms in the field and likely cause immediate symptoms, such as a runny nose, in those exposed, said McDonough, a research psychologist at the U.S. Army Medical Research Institute of Chemical Defense.
Researchers have been re-evaluating whether there are long-term health effects from exposure to low doses of nerve agent because little is known about it. Published studies didn't show strong evidence of serious and lasting health effects in cases where there were no acute symptoms at the time of exposure, McDonough said.
Dosage levels used in this experiment probably would cause acute symptoms if the nerve agent were vaporized, the expected delivery method on the battlefield. Pupils would constrict to the size of tiny dots, vision would dim and noses would run, McDonough said.
Guinea pigs were divided into three groups and received injections five days a week for two weeks. One group received only saline injections, another group was injected with one-fifth of the lethal dose of sarin, and the third group was injected with two-fifths of the lethal dose.
Because they were exposed to sarin through injection and not vapor, there were no acute symptoms from the nerve agent. But researchers were looking for the nerve agent's effect on the central nervous system, and theorized that at the dose levels used, they might see some long-term impact on behavior.
Scientists debate whether Desert Storm veterans were repeatedly exposed to low-levels of nerve agent as a possible explanation for some of their ailments, McDonough said.
Researchers at the chemical defense institute hope the study prompts further research. If they validate the results at this dose level, researchers will evaluate the potential impact of lower dose levels on the central nervous system.
Steve Robinson, executive director of the National Gulf War Resource Center, said the results show promise for Persian Gulf War veterans. The findings could help build the linkage needed for the Department of Veterans Affairs to presume illnesses are service-connected for veterans who were near Khamisiyah, Iraq, when a chemical weapons depot was destroyed there in 1991.
"It points in the direction of what has been the gut feeling in veterans all along, that exposures are causal factors in their illness," Robinson said.
Posted 12/19/2002 7:21:57 PM
http://www.veteransforcommonsense.org/article.asp?id=209
Copyright material is distributed without profit or payment for research and educational purposes only, in accordance with Title 17 U.S.C. section 107. Reference: http://www.law.cornell.edu/uscode/17/107.shtml
Veterans for Common Sense is an ad-hoc organization of Gulf War veterans working to ensure the debate over war considers all necessary issues.
"ASK YOUR PEST CONTROL COMPANY OR STATE REGULATOR TO SHOW YOU ANYWHERE ON THE LABELS OF THE VARIOUS "REGISTERED PESTICIDE POISONS THEY USE AND/OR RECOMMEND WHERE IT STATES THIS POISON IS SAFE FOR HUMANS AND/OR PETS."
If you would like to be included in our mailing list for continuing information on pesticides, please email us at list@safe2use.com.