A field sampling and analysis protocol for assessing occupational exposure and risk from military munition storage magazines

An occupational health study was conducted inside reinforced-concrete earth-covered munitions storage magazines (ECMs) at Fort Wingate Depot Activity (FWDA), a former military facility near Gallup, New Mexico. A two-phased approach was used: (1) HEPA vacuuming of bulk dust and (2) wipe sample verification post-vacuuming. Site-specific occupational health criteria were derived to evaluate potential risk from inhalation of bulk dust (Phase 1) and dermal contact of residual dust (Phase 2). In Phase 1, no explosives detections exceeded site-specific screening criteria. Any explosives detected, with or without criteria were carried forward into Phase 2. In Phase 2, no exceedances were noted for detected explosives with criterion. Using structure/reactivity characteristics within the explosives category, surrogates were assigned to the six (6) explosives without occupational health screening criteria. Based upon structural similarities within the analysis category, assignments of surrogates to explosives without criteria did not adversely impact the study conclusions. In Phase 1, lead was detected in bulk dust in all 35 igloos and all detections exceeded the applicable criterion for commercial/industrial workers. In Phase 2, all lead detections in wipe samples were below the wipe screening criteria. Study results indicated the ECM interiors posed no unacceptable dermal occupational risk for explosives or lead residues following bulk dust removal. High-efficiency particulate air (HEPA) filter vacuuming of interior bulk dust in ECMs at FWDA reduced occupational risk/hazard for exposure via inhalation and dermal contact for commercial/industrial worker activities under worst-case exposure conditions. Both phases of this sampling design are widely applicable, provided the site-specific assumptions made for this study are evaluated for suitability to another specific application and adjusted if needed.