The air over there: ARL's Battlefield Environment experts' collection of risky, tiny particles could solve future mysteries in Soldier medicine
August 16, 2011
- ARL research could equip Defense Department with tools to find out what is in the air affecting the breathing of Soldiers.
- ARL deployed DRUM Sampler at Camp Victory in Iraq.
- Models from NOAA help ARL researchers determine exactly where particles collected come from.
Research led by U.S. Army Research Laboratory experts in battlefield atmospheres could equip the Defense Department with additional tools to find out exactly what, if anything, is in the dirty, dusty, dark and by all accounts, bad air that could affect the breathing of Soldiers returning from wars in Iraq and Afghanistan.
If this information were available decades ago, perhaps more effective treatments could have been prescribed to address what's become known as the Gulf War Syndrome.
ARL deployed the Aerosol Davis Rotating-drum Universal-size-cut Monitoring (DRUM) Sampler at Camp Victory in Iraq, at Bagram Air Base and Kandahar in Afghanistan, and most recently the Horn of Africa.
Its collection now makes up an 'aerosol samples library', of sorts, that any military doctor or other research interest can access by date and even hour to identify trends in atmospheric conditions and find both total aerosol concentration, as well concentrations of individual elements like lead, iron, nickel, and sulfur, that seem to correlate with Soldier health complaints.
"We're not health professionals here; we're aerosol scientists so we don't know the details about all of the things that are going to cause health problems down the road. But we do know that if there's lead in the air, whether it's from cheap gas or industrial processes, that that's bad stuff and if we're seeing significant levels of lead in the particulates, then that's something we know we have to look out for," said Dr. Alan Wetmore, of ARL's Atmospheric Sensing Branch.
Understanding the atmospheric aerosols where Soldiers are deployed could give defense officials critical information needed if, by chance, trends suggest Soldier illnesses are linked to atmospheric conditions, said Pamela Clark, chief, Battlefield Environment Division.
Most of ARL's current research in this area could help answer just what exactly was floating around in the air there, from a retrospective view but advances in research are leading ARL to combine a number technological applications to create a 'kit' that will enable real time analysis to see what's floating in the air right now or what's expected to float soon, she said.
ARL's work began in 2008 when researchers first teamed up with the Geophysical Institute at the University of Alaska to investigate the chemistry of atmospheric aerosol samples to establish a baseline understanding of what's in the air and ground in Baghdad, Iraq. The sampler is a roughly 30-pound, two-foot instrument developed by the University of California-Davis in the 1980s that captures aerosols and allows a variety of useful, size and time-resolved measurements of the aerosol's composition and concentration. This technology is believed to take the most detailed retrospective record of what Soldiers are exposed to in the air they breathe.
Every three weeks, sampling drums placed overseas are retrieved, sent back for analysis and replaced with new drums.
"The drum sampler runs continually," said Wetmore. "The air flows in and through eight stages. Each stage collects successively smaller particles onto the Mylar strip."
"Because we know when we turn on the sampler and what speed the drums that the particles impact on rotate, it's just like a clock. We can read off – based on the position on those strips – how many hours since we turned it on that those samples were collected."
He said the technology allows the Army to look at the chemical elements captured in the sampler, particularly elements like lead, nickel or chromium in particles one micron and smaller particles that get deep into the lungs. "The very large particles don't ever get past your nose and have much less of a chance of making you ill," he said.
Matter resembling a greasy smudge stays behind on Mylar substrates that are analyzed with several techniques: two transmission measurements to determine total aerosol; those Mylar strips are then examined to identify the unique signatures of atomic elements using X-ray Fluorescence with a Synchrotron particle accelerator that can generate high intensity X-rays. That's how researchers determine how much lead, magnesium, or silicon, for example, is captured from air samples they collected.
With this information, military doctors would be better able to have a record of possible environmental contributors to trends they see in medical cases. Also, those who create protective equipment like uniforms and masks could better understand and characterize the threat of dust to Soldier health.
Using a model created by the National Oceanic and Atmospheric Administration helps ARL researchers determine exactly where particles they collected came from. It's called HYSPLIT, or hybrid single-particle Lagrangian Integrated Trajectory model, a complete system for computing simple air parcel trajectories to complex dispersion and deposition simulations.
This information, Wetmore said, will "help (the military) answer the question, maybe years down the road where Soldiers suddenly show up in large numbers with illness, was it something that came from where they were deployed, was it something they breathed?"
Starting in 2011, ARL began collecting aerosol samples in Djibouti located on the Horn of Africa. ARL teamed with the U.S. Army Public Health Command to set up technology to get real-time and retrospective information about elements in the air near Camp Lemonnier, the primary base of U.S. Africa Command operations in that region.
With the production of charcoal as a primary income generator, since their crops and livestock can't survive drought or scorching heat, black carbon emissions are high there.
Burn pits are common, said Deryck James, a meterological technician in the Atmospheric Sensing Branch. He said it's not unusual to find burn pits about the size of two high school stadiums with burning trash that hasn't been separated. "So you had everything from tires to dead animals, you had carcasses ...from the slaughter house and... carcasses that were just from off the street. It was horrible. It was something to see. And that in itself, for me, was an eye opener. It was a bit worst than what I had experienced in theater and it's only about one mile away from the base camp."
He said the base camp is located downwind from the burn pit, and an analysis of prevailing wind conditions indicates that the camp is often subjected to burn pit smoke, which makes an ideal location for the Army to continue air quality studies.
ARL is also using real-time measurements from an Aethalometer, an instrument that uses optical analysis to determine the mass concentration of black carbon particles collected from an air stream passing through a filter.
Coupled with meteorological stations for predictive analysis, Army researchers can now understand potential threats as they happen, or before they happen. One goal is to give commanders a heads up for "Code Red Days"; so they can make informed decisions about elective activities.
Researchers at the University of Arizona are looking for new ways to identify biological components in the sample strips without destroying them as current analysis does. In some early biological research, samples showed the presence of several bacteria, some that could cause a variety of human infections.
ARL is looking to expand local meteorology and meteorological modeling to determine sources and source regions. Their research is also expanding to begin burn pit simulation in the lab. The Naval Health Research Center in cooperation with the Army Public health Command is leading an effort at Wright Patterson Air Force Base to build an indoor burn pit to simulate the smoke that is experienced in theater. This smoke will be captured, analyzed and studied to determine what the health impacts are for Soldiers.
"Having served in the Gulf War and experiencing it firsthand, I've seen at first how the burning of the oil fields, the clutter of the air, no sunlight due to smog, smoke plumes in the air," said James, a retired sergeant first class with 22 years of honorable service. "It was no surveillance in the set up of the time to monitor air quality. So getting back and having battle buddies as we call them, comrades in arms, start to suffer from illnesses that was unexplained and up to this day we still cannot put a finger on exactly what the causes were, sheds a lot of light on having these instruments in place at that time could have possibly proved or disproved what those causes were."