Data exclusively shared with Military.com from a live-fire mortar exercise by U.S. Army troops indicates that simply standing near mortars can significantly disrupt Autonomic Nervous System, or ANS, functioning within a day to worse levels than seen in concussed college athletes or elderly hospital patients.
The data was provided by the doctors behind the Warfighter Monitor, a product developed by Tiger Tech Solutions, and indicated that the mortars were causing "overpressure" for troops -- ostensibly pressure waves that impact a body -- at potentially dangerous levels. Those same overpressure risks were found from other weapons systems, like artillery pieces.
The troops wore devices measuring their (ANS) functioning -- which manages "fight or flight" and "rest and digest" functions, affecting involuntary processes such as heart rate and blood pressure -- in November. The test results showed ANS functioning decreased by 33% compared to a healthy baseline, compared to 9% for airborne jumpers and 12% for concussed college athletes. The long-term effects remain unknown, but interviews with veterans, doctors and researchers indicate that the data appears to be the first to show the real-time impact of heavy caliber weapons on the human nervous system and show immediate effects of blast exposure on bodily functions.
"The data from the mortarmen is troubling," said Dr. Hector Davila, one of the doctors who led the research, works at Mount Sinai Medical Center in Florida and is also an Army veteran. "The ANS is an extremely delicate system, and we saw these adverse effects in one day."
ANS dysfunction often results from head injuries and can yield symptoms known as dysautonomia, including temperature irregularities, heart rate issues, gastrointestinal problems and headaches.
Those symptoms were experienced by former U.S. Army artilleryman Alexander Sabol, who has yet to turn 30 years old.
There are nights when Sabol feels as if he's at war with his body -- with uncontrollable sweating that sometimes gets so bad, it'll soak his bed, forcing him to move to his couch to sleep. When that gets drenched, he'll move to the floor.
Sabol said his body felt great when he deployed to Iraq in 2016 as a 21-year-old member of the 101st Airborne Division's 1-320th Field Artillery Regiment, operating a M777 155m artillery piece. It's a large gun capable of launching a 100-pound high explosive shell for miles.
But during the deployment, which saw Sabol's unit fire more than 6,000 shells in anti-ISIS operations, something changed.
Beyond his body's inability to regulate his temperature, Sabol dealt with headaches and mental health concerns that have left him with reduced functioning and impaired his quality of life. Then he started to suffer stomach, heart and breathing issues, too.
"There's times where my body will randomly freak out and start going crazy," Sabol said. "It's like I'm having a panic attack even though nothing caused it; my heart will start racing out of nowhere like it's trying to bust through my chest. I've had irritable bowel syndrome since I've come back, too, that hasn't gone away, with intense pain in my abdomen and my chest."
Brig. Gen. (Ret.) Stephen Xanakis, a psychiatrist and former Army medical corps officer who was a senior adviser to the Defense Department on neurobehavioral conditions, said the broader effects of blasts yielding symptoms such as Sabol's are becoming clear.
"Blast injuries affect the entire body," Xanakis said. "Sensitive sensors in our body maintain system functions, and blasts can harm these at a microscopic level, disrupting signal transmission and negatively impacting cardiovascular health, blood flow and breathing."
Sabol wasn't the only one in his unit of just more than a hundred in Iraq to suffer these issues, with over half of his eight-man section alone finding themselves with mental health conditions such as depression and multiple suicide attempts. Others from his deployment are now dead -- some from suicide, others from brain-related medical issues, Military.com found after conversations with five other soldiers who served in the unit.
An Invisible Killer
Sgt. 1st Class Tyler Chatfield, a soldier from Sabol's unit, experienced similar heart attack-like symptoms before he died by suicide in 2017, while Sgt. 1st Class Joshua James, another of Sabol's friends, also had physical issues before his death by suicide; both men had revealed in the conversations with others that their quality of life had been negatively impacted.
Sgt. William Schmaltz, another artilleryman in Sabol's unit, suffered a concussion from a blast overpressure event in Iraq that required medical evacuation to Germany during their deployment.
On Jan. 10 of this year, Schmaltz died in a hospital in Tennessee at age 33, after suffering complications from a sudden seizure and brain bleed. He was medically retired from the Army in 2018, and those who served with him believed it came from the blast overpressure-related brain injury he suffered in Iraq.
"I feel like all those shells we fired in Iraq played a role," Sabol said. "All of us were pretty healthy when we deployed in 2016; these issues are not normal. I feel like something is physically wrong."
Until recently, the impact of blasts on the brain was not fully recognized. Reports from Military.com and The New York Times have increased public awareness. Congress passed the Blast Overpressure Safety Act, and data shows that military personnel in jobs exposed to blasts, including artillerymen, combat engineers, tankers and mortarmen, have higher suicide rates than those not in those jobs, and their rates are more than 200% higher than the national average.
While the link between Traumatic Brain Injuries (TBIs) and higher risks of hypertension, diabetes, stroke and gut health issues, has been established, it hasn't been clear as to exactly how the overpressure causes those symptoms. ANS dysregulation may be part of the answer.
Xanakis, the former Army Medical Corps officer, said he tried to convince the Defense Department about the broad threat of injuries from blasts starting in the early 2000s, but he couldn't make any progress. For him, the DoD missed ample opportunity to delve deeper into the symptoms service members and veterans such as Sabol are reporting.
"We should have moved beyond just neurocognitive tests and start conducting full autopsies and assessments of those exposed to blast," Xanakis said. "We need to stop separating these symptoms from each other."
The field of ANS science is rapidly evolving, with questions remaining around just how this disruption occurs. One common method to measure ANS function is to use heart rate variability tools with electrocardiogram (ECG) readings, which has been done with athletes, COVID-19 patients and military parachutists.
The DoD's Traumatic Brain Injury Center of Excellence has shown interest in using HRV tools to better understand TBIs. In November, a U.S. Army mortar unit was evaluated using the Warfighter Monitor; small device worn on the arm that looks akin to a fitness band, and is placed at the end of a service member's T-shirt. Data was compared to previous research using the monitor on college athletes' recovery, military aviators and FDA-approved COVID monitoring devices.
Baseline measurements were taken before training, and other measures were taken immediately after and a day later, revealing large-scale ANS dysregulation. Taking the additional step of measuring the air quality around the weapons, the Warfighter Monitor team also found that the air became extremely toxic. Currently, the DoD mostly utilizes blast gauge devices to monitor how much overpressure service members are exposed to; those instruments don't track how troops' bodies are responding when this exposure occurs, although there is new research being conducted on blood biomarkers.
"By looking at just the blast, we're not getting the full picture of the human body," said Dr. Howard Wittels, chief of anesthesiology at Mount Sinai Hospital and the other lead scientist on the research. "It's like looking [at] how punches damage the body by just looking at punch power, without thinking about what's happening internally when someone gets hit. What we're seeing here has implications for how the military does in training and what practices they have around exposure."
Long-Term Questions
For younger veterans such as Sabol who are reporting issues, it is unclear what long-term ANS dysregulation looks like. The experience of older veterans exposed to blasts may offer clues.
Brian Farrell, a retired soldier who served 24 years in the Army, spent most of his career firing mortars. For decades, he has battled a series of puzzling physical symptoms that he now feels are due to blast exposure.
"One exercise after firing rounds, there were just days where I was just puking and couldn't eat or walk," Farrell said. "There are times where I would just be walking, and I would just randomly be out of breath or my heart would start racing. This is on top of the headaches which have persisted. One day, you feel like a killing machine, and then your body slowly starts falling apart."
Farrell was diagnosed with mild TBI from his exposure to blast overpressure during service. To understand his symptoms, he joined a Facebook group called the Cohort of OverPressured Warfighters, several members of which are attempting to work with Congress and the DoD on solutions for blast overpressure and seek legislation to provide presumptive care for veterans in blast-exposed jobs.
Farrell found others with similar medical issues to his own, including gut pain, random heart attack-like symptoms and breathing difficulties. Farrell also knew people he served with who died from medical problems related to the brain, akin to William Schmaltz.
"I didn't know so many people were talking about this," said Farrell. "It made me think of how something like the propellants in the mortars could be affecting us."
When contacted by Military.com, military health system officials responded via email that they understand that many common mild TBI and concussion symptoms are likely the result of disruption to the ANS and that "ANS biomarkers may have the potential to demonstrate the continued physiological impacts of concussion despite reported symptom resolution." The officials said that more research is needed to better understand the problem, and such studies are being conducted with academic and federal partners.
Such research will take time to do correctly. For veterans and service members like Alexander Sabol, time is of the essence.
"Sometimes it all feels so random," said Sabol. "I want to live to an old age."
Daniel Johnson is a doctoral fellow at the Hussman School of Journalism and Media at UNC-Chapel Hill. He was a journalist for the U.S. Army in 2016 in Iraq and has previously written for The New York Times, Washington Post and Slate Magazine.
