VA research center studies effects of environmental hazards

By Austin Camacho,
OSAGWIMRMD Public Affairs

WASHINGTON, May 11, 2001 (DeploymentLINK) -- Scientists at the Department of Veterans Affairs are working to learn what kinds of exposures during a military career might result in illness when a soldier, sailor, airman or Marine becomes a veteran. That concern is demonstrated by the VA's Environmental Hazards Research Centers, established to increase the knowledge about what exposure to chemicals might do to servicemembers during conflicts.

Roberta F. White, Ph.D., a neuropsychologist, has been research director of the Environmental Hazards Research Center at the Boston VA Medical Center since the program began in 1994, and the program's overall director since 2000. She and her team of about 20 scientists and technicians began their work because of concerns about the suspected causes of illness in Gulf War veterans, including chemical warfare agents and pesticides.

"In 1994, we wanted research centers that would look at these kinds of exposures and people's health in connection with the Gulf War experience," said White.

Several research papers were published based on the work done by the Center. Their results pointed to a relationship between self-reported exposures to specific chemicals and symptoms in the body systems that would be associated with those chemicals. For example, people reporting pesticide exposure had cognitive complaints and neurological symptoms. Their work also indicated that Gulf War veterans, as a group, reported many more health complaints than expected.

"Like every other study," said White, "we've seen a great difference between the number of health symptoms in Persian Gulf veterans and the symptoms in other veteran groups, even some groups that were deployed to other places during the Gulf War era."

Scientists from the Center were able to study a group of Gulf War veterans when they first returned from the deployment, and have followed up with that group four times. Data collected from those studies are very complicated to analyze, but some conclusions can be drawn.

"We've found that some people who believe they were exposed to chemical warfare agents because they had to suit up or were around scuds performed worse on neuropsychiatric tests than the Gulf veterans who don't. People who reported pesticide exposure have a lot more mood complaints than those who didn't."

She also says her team found the rate of post traumatic stress disorder to be very low in Gulf War veterans.

Today, the Center has a broader mission that includes the study of environmental exposures that may have occurred during active military duty, without specific reference to the Gulf War. White is quick to point out that everything the Environmental Hazards Center accomplishes is a team effort. The VA staff works closely with Boston University Medical School and the School of Public Health to pursue basic and clinical research in the field of environmental and occupational health.

"Our center is developing ways to assess exposures that people may have had in the military to chemicals that may be affecting their health when they come in to the VA," said White. "We're also looking at clinical ways of detecting very early subtle effects of chemical exposures."

Different chemicals tend to attack different organs or body systems. Asbestos, for example, usually affects the respiratory system. The Boston Center is primarily concerned with those chemicals that affect the central nervous system. White says she's very interested in pesticides, organic solvents and chemical warfare agents such as sarin. These could possibly cause many of the types of symptoms Gulf War veterans have reported, things like headaches, memory loss, sleep disturbance, depression and concentration problems. White says harmful exposures are not a new problem. After all, World War I servicemembers faced mustard gas. And no one can say if the risks will be worse in the future.

"It depends on how much people use chemical warfare agents," White said. "It depends on what chemicals are used in other aspects of military deployment." Those chemicals could include pesticides, cleaning fluids or something as controversial as depleted uranium."

To better prepare future military forces for a wide variety of possible exposures, the research center is working to more quickly spot the evidence of exposures. One of White's research specialties is behavioral toxicology - the study of the effects of exposure to toxic substances on behavior and the central nervous system.

"If the central nervous system is the target of a chemical," White says, "you'll see it in behavior before you'll see an obvious abnormality on a neurological exam or a change in an EEG or an MRI scan. The neuropsychological tests I use are very sensitive for picking up early indicators of exposure to chemicals that cause changes in the brain."

Suspecting that a servicemember was exposed to something does not open the door to just what the person was exposed to, at least not yet. Chemicals that attack the nervous system create similar symptoms. And many of them are not as easy to detect as lead. White started studying workers with occupational exposure to lead in 1980. A recognized technique allows scientists to establish the "body burden," that is, how much lead is in a person's system. White says some day it may be possible to detect the body burden of chemical exposures, or find some other biological marker. In the meantime, there are other avenues to explore to distinguish which exposure is causing certain health effects.

"There are some differences in different classes of compounds in the kinds of behavioral effects they have," White said, "because different compounds affect different parts of the brain. While what people say is wrong with them has a lot of overlap from one chemical to another, the actual kinds of changes you see on cognitive tests or behavioral tests can vary among chemicals."

White says the research center is also pursuing even more high tech possibilities. Using magnetic resonance imaging of the brain, scientists are able to actually see changes in the amounts of certain chemicals called neurotransmitters. Some of these changes may be associated with different chemical exposures. Enough research could reveal predictable patterns in those changes.

"Maybe at some time in the future, when we know more about this, we'll be able to use that type of information to get a handle on what people might have been exposed to," White said.

White also said that brain imaging may some day allow doctors to clearly define some of the effects of exposure to toxic chemicals that are otherwise very difficult to quantify and measure. For example, her studies of Japanese victims of exposure to sarin indicated that, a year after their exposure, their primary symptom was a mood change. She believes that the sarin affected the parts of the brain that mediate emotions. By looking at the functioning brain, new imaging techniques could help to verify suspected symptoms.

"If these brain structures start functioning or looking different after an exposure that causes an emotional change, maybe we can figure out what happened to people," continued White. "One of the aims of my research is to try to figure out some other ways of documenting the change that don't rely on a patient saying 'I feel angry,' or a spouse saying 'he's different'."

She admits there were challenges to working with Gulf War veterans that made that research different from her previous work with lead exposure. For one thing, Massachusetts has a lead registry that lists people who had a known high exposure to lead. She was able to do those studies with a population of people with a measurable exposure. Exposure information on Gulf War veterans is lacking.

"We know something about what things were out there," says White, "but we don't know how much of any given chemical each person was exposed to. We don't know the dose."

For occupational exposure studies it's fairly simple to go into a factory and put a small dosimeter on worker's lapels to see how much solvent enters their environment during the day. White says similar types of recording devices would be a great help in understanding military exposures as well. And, in fact, military units currently maintain much better environmental surveillance on deployments than they did during the Gulf War. Armed with a record of what a person was exposed to in their military and occupational career, plus the tools being developed at the Environmental Hazards Research Center, White believes that someday wartime chemical effects may be less mysterious.

"Then we'll have some idea of what kinds of chemicals they may have worked with or been around either in different conflicts or in their daily life," White says. "That will give us some cues about what the health effects might be. We also hope to have ways of picking up chemical effects at a very early stage. Then, if you have people coming back from something like the Gulf War and they have central nervous system effects, maybe by knowing about the patterns of different chemical exposures on functional imaging or on neuropsychological testing we'll be better able to figure out what might have happened to them."

It's an ambitious goal, but White says the whole purpose of her research is to try to find effects at earlier and earlier stages to prevent clinical disease and dysfunction later in life. When we consider the chemical agents, industrial pollution, pesticides and various other potentially toxic substances our forces could encounter when deployed around the world, it seems clear that the work of the VA's Environmental Hazards Research Center could be important, not just to today's veterans, but to veterans of the future as well.