Blast Overpressure in Military Training: The Invisible Readiness Risk and How to Reduce It.

Written By Michael Eaves

Blast overpressure (BOP) is not new to warfighters. What’s new is the growing consensus that repeated, low-level blast exposure—especially during training—can accumulate into a real brain-health and readiness problem, even when no one is “knocked out,” visibly injured, or diagnosed with a concussion that day. The Department of Defense has elevated the issue into formal brain-health policy, and the research community is rapidly building the evidence base.

This post is written for two audiences at once: (1) military leaders, trainers, and safety professionals who live the reality of range operations, and (2) civilian policy and budget leaders who need a clear, credible primer on why BOP matters—and what practical risk reduction looks like.

1.0 What is blast overpressure?

A blast wave is a rapid spike in air pressure followed by a negative pressure phase. Blast overpressure refers to that pressure loading on the body—particularly the head, ears, lungs, and other air-filled structures. Unlike fragmentation injuries, BOP can be invisible, leaving no obvious wound while still stressing biological systems.

In military training, the most common concern is low-level or repetitive blast overpressure from shoulder-fired weapons, breaching charges, mortars, artillery, and other blast-generating events—especially when training tempo is high and exposure repeats across days, weeks, and years.

2.0 Why training can be the highest-risk environment

Combat exposure is sporadic and operationally constrained; training can be routine, repeated, and concentrated—and often involves instructors and cadre observing many more events than any single trainee.

DoD resources explicitly identify that certain weapon systems and training activities can generate BOP levels associated with adverse effects, and DoD’s brain-health guidance emphasizes minimizing unnecessary exposure and reducing the number of people in the vicinity of BOP events.

A key point that often gets missed outside the community: the “most exposed” population may not be the shooter. In a training evolution, Range Safety Officers (RSOs), instructors, and assistant gunners can be present for repeated firings across multiple teams—day after day.

3.0 What the science is showing: from symptoms to biomarkers

3.1 Symptoms can resemble mild TBI—even without a diagnosed concussion

DoD’s own blast injury research highlights that repeated low-level occupational overpressure has been associated with symptoms that overlap with mild traumatic brain injury (mTBI): headaches, fatigue, dizziness, and cognitive performance impacts that can degrade readiness.

3.2 Biomarker evidence: “subconcussive” doesn’t mean “no effect”

One influential cohort study measured changes in brain-related serum biomarkers (often used in the context of TBI) after acute, subconcussive blast overpressure exposure in military personnel—supporting the argument that measurable biological responses can occur even when exposures fall below what many would consider “injury-level” events.

More recent work continues to examine how repetitive low-level blast exposure may alter circulating biomarkers linked to inflammation, neurovascular stress, and endothelial injury—areas directly relevant to brain health.

3.3 Cumulative exposure matters

A growing theme across studies is that cumulative dose—not just single-event peaks—may predict functional changes. Military research has examined cumulative blast exposure during training (including metrics like impulse and repeated events) and ties this to changes in chronic outcomes.

4.0 The suicide connection: what we can responsibly say

Suicide is multifactorial—influenced by mental health conditions, life stressors, access to care, substance use, chronic pain, and more. It is not accurate or ethical to claim a single-cause pathway.

What the credible literature does support is that TBI history is associated with higher suicide risk in veteran populations, and DoD has published research reviews summarizing the state of evidence and the complexity of comorbidity.

A key takeaway for leaders and policymakers: if training environments can reduce preventable brain-health insults, we reduce one important risk factor in a wider, integrated suicide-prevention strategy—especially when paired with screening, early evaluation, and stigma-free access to care.

If you or someone you know is in crisis: in the U.S., dial 988 (Press 1 for Veterans) for the Veterans Crisis Line.

5.0 A practical estimate: why cadre may carry the heaviest long-term “dose”

We’re still building definitive occupational exposure limits for BOP, but DoD guidance and industrial hygiene resources emphasize that adverse effects have been reported at and above specific levels and that commands should limit unnecessary exposure.

To illustrate why cadre are often the “high-dose” group, consider a conservative, example training cycle:

  • A shoulder-fired range runs 4 relays/day

  • Each relay includes 8 firings

  • An RSO/instructor is present for all relays
    That’s 32 blast events/day. Over a 4-day range week, that’s 128 events/week. Over 20 active range weeks/year, that’s ~2,560 events/year—often at standoff distances that vary by range layout, terrain, wind, and firing position.

This is an illustrative scenario—not a medical threshold claim—but it explains the occupational reality: the same people can accumulate thousands of exposures while ensuring others meet readiness standards.

Research examining cumulative exposure in training contexts has even suggested that trainees are not always the primary at-risk group, reinforcing the need to focus mitigation on instructors and cadre.

6.0 What DoD policy is doing about it (and why it matters to Congress)

DoD leadership has issued department-wide requirements and guidance for managing brain-health risks from blast overpressure, pointing services toward standardized approaches and reference materials.

Congress has also pushed for better tracking and accountability. For example, the FY2020 National Defense Authorization Act (Public Law 116-92) contains provisions driving blast exposure documentation and longitudinal medical study requirements, and DoD reporting has addressed implementation.

Meanwhile, oversight and systems integration continue to evolve—including how DoD and VA connect exposure and health information for care and research.

For civilian decision-makers, the message is clear: this is not a fringe topic. It is now a readiness, medical, and policy priority with ongoing requirements.

7.0 The hierarchy of controls: the fastest path to reduced risk

If your goal is real exposure reduction—not just awareness—the best safety programs follow the hierarchy of controls:

  1. Eliminate/Substitute (often not possible—training must happen)

  2. Engineering controls (change the environment so exposure is reduced)

  3. Administrative controls (limit time/rounds, rotate personnel, increase standoff)

  4. PPE (limited utility for blast wave energy; hearing protection helps ears, not overall impulse)

DoD guidance emphasizes reducing unnecessary exposures, minimizing personnel near blast events, and using training strategies that reduce exposure where appropriate.

The gap is that many ranges lack a portable, mission-compatible engineering control that can be deployed quickly and repeatedly across different weapons and training configurations—without rewriting the entire training program.

8.0. EBSS: a purpose-built engineering control for training ranges

EBSS (Explosive Blast Shield System) was created specifically to reduce blast overpressure exposure for the shooter, assistant gunner, RSOs, and training cadre during shoulder-fired and large-caliber weapons training—without compromising realism or throughput.

What makes EBSS different is the intent: reduce the blast wave reaching personnel through an engineered barrier approach that is compatible with how military ranges actually operate.

  • Training-integrated: Designed to fit into existing range procedures and firing points

  • Cadre-focused: Built for the people who accumulate the most exposure over time

  • Operationally realistic: Enables training standards to be met while reducing unnecessary blast load on bodies and brains

In internal prototype testing, EBSS has measured large reductions in blast overpressure behind the shield in representative training setups (results vary by weapon, positioning, and environment). In other words: EBSS is designed to be an engineering control—the class of mitigations that usually produces the biggest risk reduction fastest.

Bottom line: You can’t “policy” your way out of physics. If the blast wave is the hazard, a barrier system that redirects and attenuates that wave is one of the most direct ways to reduce exposure while preserving readiness.

9.0 What leaders can do now

If you oversee training, procurement, or force health protection, here are immediate, actionable steps:

  • Identify high-dose roles (RSOs, instructors, assistant gunners, breach cadre) and prioritize them for mitigation.

  • Measure and track exposure where possible and align with DoD documentation direction.

  • Use administrative controls intelligently (rotation, minimum rounds to standard, standoff discipline).

  • Adopt engineering controls where they do not disrupt training outcomes—this is where the largest reductions typically occur.

10.0 Closing thought: readiness is not just performance—it’s longevity

The United States asks a small population to shoulder a disproportionate burden of risk. If we can preserve training realism while reducing unnecessary blast exposure—especially for the cadre who sustain readiness generation—we should.

Blast overpressure is an invisible threat, but it’s no longer an invisible problem. The research is maturing, DoD policy is moving, and Congress is paying attention.

EBSS exists to turn that momentum into a practical range-ready mitigation—so training can stay hard, realistic, and repeatable, without silently compounding a preventable brain-health risk.

References (Clickable)

Michael Eaves
Previous

Policy & Accountability on Blast Overpressure: How DoD and Congress Are Turning “Invisible” Exposure into Managed Risk