Whole-body inhalation of nano-sized carbon black: a surrogate model of military burn pit exposure

Abstract

Objective Chronic multisymptom illness (CMI) is an idiopathic disease affecting thousands of U.S. Veterans exposed to open-air burn pits emitting aerosolized particulate matter (PM) while serving in Central and Southwest Asia and Africa. Exposure to burn pit PM can result in profound biologic consequences including chronic fatigue, impaired cognition, and respiratory diseases. Dysregulated or unresolved inflammation is a possible underlying mechanism for CMI onset. We describe a rat model of whole-body inhalation exposure using carbon black nanoparticles (CB) as a surrogate for military burn pit-related exposure. Using this model, we measured biomarkers of inflammation in multiple tissues. Results Male Sprague Dawley rats were exposed to CB aerosols by whole body inhalation (6 ± 0.83 mg/m3). Proinflammatory biomarkers were measured in multiple tissues including arteries, brain, lung, and plasma. Biomarkers of cardiovascular injury were also assayed in plasma. CB inhalation exposure increased CMI-related proinflammatory biomarkers such as IFN-γ and TNFα in multiple tissue samples. CB exposure also induced cardiovascular injury markers (adiponectin, MCP1, sE-Selectin, sICam-1 and TIMP1) in plasma. These findings support the validity of our animal exposure model for studies of burn pit-induced CMI. Future studies will model more complex toxicant mixtures as documented at multiple burn pit sites.

Prevalence of Burn Pit Associated Symptoms Among US Veterans Who Utilize Non-Veteran’s Affairs Private Healthcare

“…[18][19][20][21] A recent experimental model for military burn pit exposure found that inhalation of burn pit-related nano-sized surrogates induced a systemic inflammatory response with significant elevation of seven inflammatory biomarkers in whole brain tissue. 22 Those authors additionally elaborates that these inflammatory markers lead to chronic multisystem illness affecting the nervous, among several other body systems. Additional research and further consideration of PACTact approved medical benefits for neurological symptoms and diagnosis could be reviewed and expanded to provide veteran aid.…”

“…Military occupational and environmental exposures of airborne toxins have been linked to elevated risk for multiple system disease and cognitive decline 18–21 . A recent experimental model for military burn pit exposure found that inhalation of burn pit-related nano-sized surrogates induced a systemic inflammatory response with significant elevation of seven inflammatory biomarkers in whole brain tissue 22 . Those authors additionally elaborates that these inflammatory markers lead to chronic multisystem illness affecting the nervous, among several other body systems.…”