Aggregate exposure. Exposure to a single chemical by multiple pathways (e.g., air, food, drinking water) and routes of exposure (inhalation, oral, and dermal).

Benchmark dose (BMD). Dose with a specified low level of excess health risk, generally in the range of 1% to 10%, which can be estimated from data with little or no extrapolation outside the experimental dose range. It is derived by modeling the data in the observed experimental range, selecting an incidence level within or near the observed range (e.g., the effective dose producing a 10% increased incidence of response), and determining the upper confidence limit on the model.

Chemical casualty estimating guidelines (CCEGs). Media-specific chemical concentrations expected to cause health impairments sufficient to reduce unit strength (i.e., pose a medical threat). The CCEGs are used to evaluate course-of-action options that are expected to involve chemical exposures.

Cumulative risk. Likelihood of occurrence of an adverse health effect from exposure to multiple chemicals that have common modes of toxicity from all routes and pathways.

Deployment. Unless specifically defined differently by the commander/leader responsible for the mission at hand, a deployment is defined as a troop movement resulting from a JCS/Unified Command deployment order to a land-based location outside the Continental United States that does not have a permanent U.S. Medical Treatment Facility (i.e., funded by the Defense Health Program) that lasts 30 or

more consecutive days (U.S. Department of the Army, HQDA Ltr 1-0-1, 27 June 2001).

Force health protection. A unified and comprehensive strategy that aggressively promotes a health and fit force and provides full protection from all potential health hazards throughout the deployment process. Its major ingredients include healthy and fit force promotion, casualty and injury prevention, and casualty care and management (Department of the Army, HQDA Ltr 1-0-1, 27 June 2001).

Health threat. Refers to an individual soldier’s health. It includes hereditary conditions that manifest themselves in adulthood, individual exposure to an industrial chemical or toxin where others are not exposed, or other injuries and traumas that affect an individual’s health rather than the health of the unit (FM 4-02.17, Department of the Army, 28 August 2000).

Long-term exposure. Exposure to a toxicant or health threat with a maximum duration of one year (Department of the Army, HQDA Ltr 1-0-1, 27 June 2001).

Long-term health effect. A health effect, usually adverse, that manifests itself a significant period of time (months or years) after the causative event (i.e., exposure to a toxicant). This term is also used to describe a health effect that persists for a relatively long period of time (months or years) (Department of the Army, HQDA Ltr 1-0-1, 27 June 2001).

Medical threat. A subset of health threats that have the potential to degrade a unit’s combat (or mission) effectiveness. Is defined as “a collective term used to designate all potential or continuing enemy actions and environmental situations that could adversely affect the combat effectiveness of friendly forces, to include wounds, injuries, or sickness incurred while engaged in a joint operation” (Joint Publication 4-02, Doctrine for Health Service Support in Joint Operations. 26 April 1995).

Military exposure guideline. An estimated chemical concentration above which certain types of adverse health effects might begin to occur in individuals within the exposed population after a continuous, single exposure of specified duration.

Occupational and environmental health. Human health issues impacted by hazardous materials, agents, organisms, or conditions found in a specific work environment or in the natural environment (Department of the Army, HQDA Ltr 1-0-1, 27 June 2001).

Occupational and environmental health threats. Threats to health of personnel and military readiness created by exposures to hazardous

agents contained in or produced by weapons systems, as well as exposures to environmental contamination or toxic industrial materials (Department of the Army, HQDA Ltr 1-0-1, 27 June 2001).

Short-term exposure. Exposure to a toxicant or health threat with a maximum duration of two weeks (Department of the Army, HQDA Ltr 1-0-1, 27 June 2001).

Short-term health effect. A health effect, usually adverse, that manifests itself shortly after the causative event (i.e., an exposure to a toxicant). This term is also used to describe an adverse health effect that persists for a relatively short period of time before subsiding completely (Department of the Army, HQDA Ltr 1-0-1, 27 June 2001).