Neuroscience and Biobehavioral Reviews · Oct 27, 2026

Repetitive low-level blast exposure and brain health: State-of-the-science and clinical priorities in 2026

By Meabon JS, McEvoy C, Crabtree A et al.

Low-level blast (LLB) exposures generated by weapons systems and explosives use are now recognized as an occupational hazard for many military and law-enforcement communities. Although individual exposures often fall below thresholds for clinically diagnosable concussion, accumulating data from human and animal studies suggest that repetitive LLB can produce subtle but durable changes in neurobehavioral function, neuroimaging markers, and blood- and CSF-based biomarkers, as well as cardiovascular and neurovascular health. At the same time, the field remains fragmented, with heterogeneous exposure metrics, characterized by non-standardized exposure quantification methods, variable outcome measures, and inconsistent longitudinal follow-up intervals. This state-of-the-science review synthesizes current evidence on LLB with a deliberate emphasis on clinical aspects that matter to Servicemembers, Veterans, and clinicians focusing on posttraumatic outcomes (e.g., psychological, cognitive, physical), reduction of risk of neurodegenerative disease, and practical pathways for exposure prevention and mitigation. We first describe contemporary definitions and patterns of LLB exposure across operational communities, followed by a critical appraisal of epidemiological studies linking LLB to symptoms, functional outcomes, and health-care utilization. We then summarize converging evidence for neurodegenerative and neurovascular risks, integrate mechanistic insights from neuroimaging, neuropathology, and animal models, and highlight emerging biomarker and computational approaches. Finally, we outline pragmatic strategies for exposure assessment, screening, and follow-up in clinical settings and identify high-priority research and policy directions. Rather than asking whether LLB is "safe" or "unsafe" in absolute terms, we focus on vulnerability and context as a roadmap for scientific and clinical development while balancing mission requirements with long-term brain health.

doi.org/10.1016/j.neubiorev.2026.107052PubMed 42945592Mechanisms