The Role of Very Low Level Blast Overpressure in Symptomatology

Abstract

Blast overpressure exposure has been linked to transient, but measurably deteriorated performance and symptomatologies in law enforcement and military personnel. Overlapping sub-concussive symptomatology associated with the very low level blast overpressures (vLLB) but high sound pressure (<3 psi) associated with these exposures has largely been ignored. Notably, the current vLLB or acoustic literature has focused exclusively on auditory defects, and has not addressed the broader concerns of Soldier health and readiness. This work was prompted by reports of symptomatology such as headache, nausea, slowed reaction time, and balance/hearing complications among personnel undergoing frequent exposures to low overpressure accompanied by high acoustic pressures. To more fully address the consequences associated with low overpressure exposures (<3 psi), a pilot proof-of-concept study was implemented, and data was acquired at two sites on the Fort Benning grenade course range. Findings indicated overpressures ranged from 0.14 to 0.42 psi (0.97–2.89 kPa) at range 1 and 0.22–0.30 psi (1.52–2.07 kPa) on range 2 of the grenade course. Corresponding sound-meter data varied from 153.72 to 163.22 dBP. Headache and long think were the most frequently reported symptoms (3/6 instructors), with lightheadedness, ringing of the ears, restlessness, frustration, and irritability also increasing in 2/6 of the instructors post exposure. Long think (prolonged thinking), ringing of the ears, restlessness, and irritability were the most severe symptoms, with the highest reported post exposure value rating a 3 on the 0–4-point scale. We demonstrate that low-level repeated overpressure exposure can result in transient symptomatology that overlaps with sub-concussive like effects.

Potential Health and Performance Effects of High-Level and Low-Level Blast: A Scoping Review of Two Decades of Research

“…Additionally, it should also be noted that because the field of blast research is rapidly evolving, even the most comprehensive literature search will rapidly become outdated as more articles are published. For example, in the year since we conducted our search, several additional papers on LLB been published summarizing epidemiological investigations ( 84 , 85 ), case studies ( 86 ), studies of training courses ( 87 ), animal studies ( 88 ), and more.…”

Neurocognitive Performance Deficits Related to Immediate and Acute Blast Overpressure Exposure

“…However, it is not known if peak overpressure is the sole driver for effects like performance impairment. It may be the case that the acoustic insult that also grows larger with larger peak overpressure is a contributing, or even primary, mechanism of effect (23, 29).…”

Editorial: Neurosensory Alterations From Blast Exposure and Blunt Impact

“…Neurosensory perturbations are the most common symptomatology observed following blast and blunt trauma to brain (1)(2)(3)(4)(5). Glasgow coma scale (GCS) for civilian injuries and threshold of injury in military personnel heavily rely on the perturbations associated with neurosensory systems to diagnose mild to severe traumatic brain injury.…”