Warfighters are required to be medically ready to operate in multi-domain, near-peer battlefields, such as dense urban environments, and the Department of Defense (DoD) currently lacks fielded capabilities to determine human exposure risks. There are current efforts underway to design a device focused exclusively on measurement of lead in bone for community populations. However, the proposed project directly addresses the DoD capability gaps by enabling the direct measurement of a wide range of heavy metal exposure in blood as well as in vivo in bone and (toe or finger) nails, which is required for advancement of the capability to identify and monitor military medical management of environmental exposure and injuries. This project will refine and validate a combat ready exposure device (CRED) that targets the measurement of lead (Pb) as well as other heavy metal (i.e., mercury [Hg], manganese [Mn], copper [Cu], and tungsten [W]) exposures. The proposed prototype technology will combine validated metrics for human absorbed dose to heavy metals with portability to permit applicability in-theater and monitoring of both acute and chronic heavy metal dose (the critical first step so subsequent engineering can move the technology to a sensor capability). Heavy metals exposure with combat sources including ammunition, burn pits, and particulate matter from improvised explosive devices, have been identified as common and of particular concern for Soldier combat readiness. Measuring metals in blood is a common biomarker used to quantify acute exposure to metals, but this measurement requires trained phlebotomists and laboratory processing time. Direct, near-real time blood Pb levels measured by the CRED will be key in the short term for implementing acute care. However, metals (such as Pb) biomarkers measured in blood are not good indicators of total body burden of cumulative exposure nor resultant potential health and performance outcomes, as they have a half-life of less than one month in blood. Pb and other heavy metals accumulate in bone remaining there for decades and in toenails remaining there for life of the nail. Therefore, the capability of measurement of heavy metal exposures in bone and toenails provides unique exposure information for monitoring repeated and chronic exposure to metals.

The proposed project is a collaborative effort between an academic institution with expertise in heavy metal research and an U.S. Army research institution focused on delivery of biomedical solutions to Warfighter performance and readiness. The project goal is to develop and validate a device prototype to detect and monitor the body burden to heavy metals exposures for use in forward operational combat as well as civilian and military higher echelon clinical care settings. The research will be conducted in two phases over 2 years. The objectives of the project are to build and validate a portable x-ray fluorescence (XRF) prototype device in the laboratory for human biomarker measurement of heavy metal body burden (Phase I) and validate the device for acute blood spot measurement of Pb, Hg, Mn, Cu, and W using blood from a single finger prick and in vivo bone Pb and toenail Pb, Hg, Mn, Cu, and W measurements compared to gold standard methods in Soldier participants (Phase II).

Having a valid, portable device to measure heavy metal dose in blood, bone, and nails is critical for initial detection and subsequent monitoring of heavy metal exposures in various environments and over Service members’ careers. In combat, acute exposures to toxic levels of metals, like those inhaled from blasts, can have immediate neurological impacts including a reduction in cognitive function as well as other systemic impacts. A field-ready device that a medic or front-line operator can employ to measure blood metal levels in minutes is critical for acute triage. Additionally, having a validated device to monitor and assess longer term exposure dose fulfills a key capability gap for continued assessment of chronic health effects that exposure to metals has on military performance and readiness and management of point of care needs.