The RSO Problem: Why Training Cadre Carry the Highest Blast Burden and What Leaders Can Do Now

Jan 20

Blast overpressure has moved from an emerging research concern to a formal readiness, occupational-health, and risk-management issue.

The Department of Defense now requires practical actions to mitigate and track blast overpressure exposure across training and operations. DoD’s current interim guideline uses 4 psi as a threshold for initiating risk-management actions until further research refines brain-health impacts.

Reference: DoD Deputy Secretary memorandum, Aug. 8, 2024

https://media.defense.gov/2024/Aug/09/2003521276/-1/-1/1/DEPARTMENT-OF-DEFENSE-REQUIREMENTS-FOR-MANAGING-BRAIN-HEALTH-RISKS-FROM-BLAST-OVERPRESSURE-OSD005281-24-RES-FINAL.PDF

For leaders who run ranges, supervise weapons training, manage breaching programs, or support indirect-fire and shoulder-fired training, the practical problem is already visible:

The highest cumulative exposure burden often falls on the people who are present for every iteration — RSOs, instructors, safety personnel, assistant gunners, breaching cadre, and range staff.

This post explains why cadre carry the highest cumulative exposure opportunity, what credible research says about repeated low-level blast exposure, and what leaders can do now to reduce unnecessary exposure without weakening training standards.Blast overpressure (BOP) has entered a new phase: it is no longer just a research topic—it’s a readiness and workforce sustainability issue. The Department of Defense now requires practical risk management actions to mitigate and track blast exposure across training and operations, using an interim guideline of 4 psi as a trigger for risk management actions until the science further refines thresholds.

Related EBSS resources:

Blast Overpressure in Military Training:
/blog/blast-overpressure-in-military-training-the-invisible-readiness-risk-and-how-to-reduce-it

Policy & Accountability on Blast Overpressure:
/blog/policy-amp-accountability-on-blast-overpressure-how-dod-and-congress-are-turning-invisible-exposure-into-managed-risk

BORS — Blast Overpressure Range System:
/bors

C-BOS — Close-Quarters Blast Overpressure System:
/cbos

Request a Brief / Pilot Discussion:

1.0: WHAT MAKES CADRE “HIGH-DOSE” BY DEFAULT

In many training environments, blast exposure is repetitive, predictable, and concentrated. That is often the opposite of combat, where exposure may be episodic and mission-dependent.

Three factors push cadre exposure upward.

1.1 Cadre are present for every firing event

A trainee may fire a limited number of rounds to standard. Cadre may supervise multiple relays, multiple teams, multiple days, and multiple courses.

That creates the core RSO problem: the shooter rotates, but the instructor stays.

1.2 Cadre are positioned for safety and coaching — not maximum distance

Stand-off helps, but range operations require line-of-sight, command and control, immediate intervention capability, and direct observation of weapon employment.

DoD policy recognizes this reality. The policy is not intended to stop mission-essential weapons training. It is intended to manage risk while preserving readiness.

Reference: DoD BOP requirements memo

https://media.defense.gov/2024/Aug/09/2003521276/-1/-1/1/DEPARTMENT-OF-DEFENSE-REQUIREMENTS-FOR-MANAGING-BRAIN-HEALTH-RISKS-FROM-BLAST-OVERPRESSURE-OSD005281-24-RES-FINAL.PDF

1.3 Range geometry can change exposure

Blast exposure is shaped by more than weapon type. Pressure can vary based on terrain, standoff, posture, berms, walls, vehicles, adjacent lanes, ground reflection, enclosure effects, and position relative to the blast source.

That means “standard” training can still create non-standard exposure for personnel standing in the wrong location on the wrong range.

References:

Blast in Context: https://pmc.ncbi.nlm.nih.gov/articles/PMC7744759/

Frontiers breaching / range staff study: https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2020.588531/full

Navy IH Field Guide for BOP / DOEHRS-IH: https://www.med.navy.mil/Portals/62/Documents/NMFA/NMCPHC/root/Industrial%20Hygiene/Acquisition%20Technical%20Support/3.%20IH%20FIELD%20GUIDE%20for%20BOP%20DOEHRS-IH%207.1.25.pdf

SECTION 2: A PRACTICAL EXPOSURE MATH MODEL (ILLUSTRATIVE—BUT CLARIFYING)

We still need better occupational limits and dose-response clarity, but you don’t need perfect science to understand the cadre problem.

Here’s a conservative illustrative scenario for a shoulder-fired or heavy-weapon training range:

4 relays per day
8 firings per relay
Cadre present for all relays

That equals 32 blast events per day.

If the range operates:

4 days per week = 128 events per week
20 active range weeks per year = approximately 2,560 events per year
Over a 5-year assignment cadence = approximately 12,800 events

This is not a medical diagnosis claim. It’s a reality check about cumulative opportunity for exposure.

Now add what the research and DoD documentation repeatedly emphasize: environmental factors can change exposure. A cadre member positioned near a wall, vehicle, berm, or structure may experience different pressure dynamics than a shooter in the primary lane.

References:

“Blast in Context” (PMC): https://pmc.ncbi.nlm.nih.gov/articles/PMC7744759/
Breaching instructors and range staff paper (Frontiers): https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2020.588531/full

SECTION 3: WHAT THE RESEARCH SAYS ABOUT REPEATED LOW-LEVEL BLAST (WHY THE “CADRE DOSE” MATTERS)

The strongest, most responsible takeaway from the literature is not “every exposure causes injury.” It’s this:

Repeated low-level blast exposure may be associated with measurable changes in symptoms, performance, biomarkers, and neuroimaging outcomes—especially when exposures accumulate over time in occupational roles.

A few examples that directly relate to cadre exposure:

Instructors and range staff have been studied directly
A Frontiers paper examined long-term occupational exposure in breaching instructors and range staff, comparing them to controls to evaluate performance and health measures.
Link: https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2020.588531/full
Imaging and behavioral correlates in experienced breachers
A neuroimaging study on experienced breachers explored potential cumulative neurological effects after repetitive low-level blast exposure using behavioral and imaging modalities.
Link (PMC): https://pmc.ncbi.nlm.nih.gov/articles/PMC7703399/
Cumulative impulse and exposure metrics may relate to symptom measures
A 2024 Military Medicine study reported that cumulative measures of low-level blast exposure (including impulse, number of blasts, and time in low-level blast occupations) showed influence on neurobehavioral symptom measures.
Link: https://academic.oup.com/milmed/article/189/9-10/e2069/7637830
DoD blast injury research literature synthesis
DoD’s blast injury research community has compiled literature reviews on neurological effects of repeated exposure, useful as an evidence map for leaders.
Link (PDF): https://blastinjuryresearch.health.mil/assets/docs/sos/lit_reviews/neurological_effects_of_repeated_exposure-lit_rev-rr-2350_final-9mar2020.pdf
RAND testimony: known concern, incomplete data, urgent prevention value
RAND testimony notes that groups like breachers and munitions range instructors are hypothesized to have more frequent exposure, while also highlighting evidence gaps and the value of practical preventive actions.
Link (PDF): https://www.rand.org/content/dam/rand/pubs/testimonies/CTA3200/CTA3250-1/RAND_CTA3250-1.pdf

SECTION 4: WHY POLICY HAS MOVED—THE 4 PSI INTERIM GUIDELINE AND TRACKING REQUIREMENTS

DoD’s 2024 memo is explicit: adverse impacts have been reported from exposures above 4 psi, and a 4 psi interim guideline will be used to trigger risk management actions until further research defines impacts. The memo identifies weapon categories known to exceed 4 psi, including breaching charges, shoulder-fired weapons, .50 caliber systems, and indirect fire.

Reference: DoD memo (Aug. 8, 2024)
Link: https://axonmedicaltech.com/wp-content/uploads/2024/08/DEPARTMENT-OF-DEFENSE-REQUIREMENTS-FOR-MANAGING-BRAIN-HEALTH-RISKS-FROM-BLAST-OVERPRESSURE -OSD005281-24-RES-FINAL.pdf

The policy also directs practical actions such as:

minimizing unnecessary personnel in the vicinity of BOP events
establishing procedures for tracking potentially exposed personnel (including in DOEHRS-IH)
recordkeeping for sensor data (even while systems mature)

Implementation resources continue to emerge, including industrial hygiene guidance for documenting BOP in DOEHRS-IH workflows.

Reference: Navy IH Field Guide for BOP / DOEHRS-IH (July 1, 2025)
Link:https://www.med.navy.mil/Portals/62/Documents/NMFA/NMCPHC/root/Industrial%20Hygiene/Acquisition%20Technical%20Support/3.%20IH%20FIELD%20GUIDE%20for%20BOP%20DOEHRS-IH%207.1.25.pdf

SECTION 5: THE LEADERSHIP CHALLENGE—DON’T CONFUSE MEASUREMENT WITH MITIGATION

Sensors, tools, and tracking programs matter—and DoD is actively building them. For example, DHA has discussed milestones in blast exposure monitoring tools intended to support training use and help minimize exposure.

Reference: DHA news release (Aug. 14, 2025)
Link: https://www.dha.mil/News/2025/08 /14/15/52/Blast-Exposure-Monitoring-Tool-Reaches-Critical-Milestone

But measurement is not the same as reduction.

If you want fewer high-dose cadre, apply the hierarchy of controls:

Elimination/Substitution (usually not feasible—training must happen)
Engineering controls (reduce the hazard reaching the person)
Administrative controls (rotation, time limits, standoff discipline)
PPE (helps hearing; limited for total blast impulse exposure)

DoD policy reinforces the intent: mitigate risk while preserving mission-essential training.

SECTION 6: WHY EBSS IS BUILT SPECIFICALLY FOR THE RSO PROBLEM

EBSS (Explosive Blast Shield System) is designed as a range-deployable engineering control to reduce blast overpressure reaching the shooter’s team and—critically—the cadre who accumulate the exposure.

EBSS is built for the real constraints of military training:

Cadre must stay close enough to supervise safely
Training must remain realistic and repeatable
Range throughput matters
Layouts change; solutions must be deployable, not permanent construction

In plain terms: when you can’t rotate cadre fast enough, can’t push them far enough away, and can’t reduce training volume without readiness consequences—engineering controls become the most practical lever.

The goal is not to eliminate blast from training. The goal is to eliminate unnecessary blast dose to the people generating readiness every day.

SECTION 7: “WHAT CAN WE DO NEXT WEEK?” A CADRE-FIRST ACTION LIST

If you want to align with DoD policy direction while improving readiness outcomes, start here:

7.1 Identify your high-dose roles and events

List training activities where cadre are repeatedly present near BOP sources (breaching, shoulder-fired weapons, mortar/artillery training support, etc.).

Helpful resources:

Warfighter Brain Health Hub: Blast Overpressure
Link: https://www.health.mil/Military-Health-Topics/Warfighter-Brain-Health/Brain-Health-Topics/Blast-Overpressure
TBICoE: Blast Overpressure Exposure and TBI
Link: https://health.mil/Military-Health-Topics/Centers-of-Excellence/Traumatic-Brain-Injury-Center-of-Excellence/Blast-Overpressure-Exposure-and-TBI

7.2 Implement stand-off and positioning discipline—then acknowledge its limits

Stand-off helps, but geometry matters. Use deliberate cadre positioning and lane design where possible.

References:

DoD memo (Aug. 8, 2024): https://axonmedicaltech.com/wp-content/uploads/2024/08/DEPARTMENT-OF-DEFENSE-REQUIREMENTS-FOR-MANAGING-BRAIN-HEALTH-RISKS-FROM-BLAST-OVERPRESSURE-OSD005281-24-RES-FINAL.pdf
“Blast in Context” (PMC): https://pmc.ncbi.nlm.nih.gov/articles/PMC7744759/

7.3. Track exposures and patterns (even if you’re not fully mature yet)

Start the record. Consistency matters more than perfection early.

References:

7.4. Add engineering controls where they preserve training value

This is where EBSS fits: protect the cadre who must remain engaged and close.

SECTION 8: THE BUSINESS CASE LEADERS CAN SAY OUT LOUD

There’s a simple readiness argument that resonates with commanders and civilian decision-makers:

Cadre are the readiness engine. Losing cadre time to symptoms, evaluation, staffing churn, or policy-driven training pauses harms readiness. Mitigation that preserves training throughput while reducing unnecessary exposure is a net readiness gain.

DoD leadership messaging around the 2024 policy reinforces that the goal is to improve combat readiness by reducing adverse impacts that remove service members from action.

Reference: DoD blast summit coverage (Army.mil)
Link:https://www.army.mil/article/279051/dod_blast_summit_brings_together_public_health_safety_experts_to_address_blast_overpressure_concerns

CONCLUSION: PROTECT THE PEOPLE WHO PROTECT THE STANDARD

BOP policy is evolving quickly. Research is expanding. Tracking tools are improving. But the cadre exposure problem is already visible in the math of training operations and the emerging evidence on cumulative effects.

If the mission is to train realistically and sustainably, the most immediate improvement comes from reducing unnecessary blast dose to RSOs and instructors through practical, range-deployable engineering controls—without reducing standards.