Assessing Chemical Exposures during Military Deployments

Military Medicine, Feb 2004 by Hauschild, Veronique D, Lee, Arthur P

Before the first Persian Gulf War, military chemical concerns were focused on life-threatening/performance-impairing effects from exposures to chemical warfare agents. Now, hazards of concern include both high and low levels of chemical warfare agents and toxic industrial chemicals in air, soil, and water. The types of health effects considered have expanded to include both immediate, acute effects (mild and severe), and delayed or chronic outcomes. Because federal exposure standards are not applicable to deployed personnel, the U.S. Army Center for Health Promotion and Preventive Medicine established military-specific exposure guidelines in Technical Guide 230, Chemical Exposure Guidelines for Deployed Military Personnel. Methods used to develop the guidelines address toxicological data limitations, uniqueness of military populations and exposure scenarios, and a risk assessment process compatible with existing military operational risk management doctrine. The Technical Guide 230 helps ensure chemical hazards are addressed in various deployment scenarios.

Introduction

Military personnel may be exposed to many environmental chemical hazards during deployments. The intentional use of chemical warfare agents (CWA) or the intentional or accidental release of toxic industrial chemicals (TICs) may expose personnel to localized high levels of toxic exposures as well as residual low-level exposures. Other exposures may result from inhalation of ambient contaminants caused by poor environmental controls at deployment sites, burning of propellants, trash, and human waste, bulk-fueling operations, pesticide spraying, or many other scenarios. Adverse health effects can also be associated with chemicals in drinking water or from contact with contaminated soil. Whereas the extent of the health effects caused by such exposures are not always entirely clear, the results may range from significant immediate effects that impact mission performance to delayed health effects that affect postdeployment quality of life. These risks from environmental chemical exposures must be assessed and integrated into over all military operational risk management (ORM).

Background

Since the mid-1990s, concerns have been raised regarding the adequacy of the Department of Defense (DoD) doctrine and technology to identify and defend troops against the possible adverse effects of low-level CWA exposure. Several reports'"4 have also pointed to TICs that may be implicated in potential health outcomes. In 1998, the Government Accounting Office concluded that the DoD had not developed doctrine that addressed low-level exposures to chemical agents either in isolation or in combination with other contaminants found on the battlefield.5

The DoD has initiated research and policies6"9 to identify the cause (environmental exposures) and effect (medical outcome) relationships associated with various chemicals. For several years now, the services have been collecting air, water, and soil samples to characterize the environmental exposures occurring during military operations.10"13 These environmental samples have been analyzed for military unique CWAs and TICs. The initial assessments of the samples were hindered by the lack of pre-established military exposure guidelines (MEGs) or standards applicable to deployments. Federal guidelines and standards (e.g., Occupational Safety and Health Administration and the Environmental Protection Agency [EPA]) are more applicable to protect workers and the civilian public for lifetime exposures.

To address this issue, scientists at the U.S. Army Center for Health Promotion and Preventive Medicine developed Technical Guide (TG) 230, Chemical Exposure Guidelines for Deployed Military Personnel,14 which provides ranges of concentration levels associated with varying degrees of effect severity. Guidelines are provided for short-term exposures (from 1 hour to 14 days) and long-term exposures (up to 1 year). TG 230 uses military ORM terminology to describe the significance of the severity levels and health effects. It also defines low level as exposures to concentrations over specified durations that would not cause immediate acute or severe health effects. Low-level exposures may result in mild or possibly delayed health effects but are not expected to cause adverse operational impacts. TG 230 is intended to be a consolidated reference tool for military preventive medicine personnel to provide expedient risk management decisions to a commander during deployments.

Methods

Existing toxicological data and risk assessment methodologies, including published health standards and guidelines, were the basis for developing the guidelines in TG 230. This process took advantage of national and international expertise used to evaluate the basic toxicological data and provided the broadest array of information for the most chemicals. Four issues had to be addressed in developing these guidelines:

* toxicological data limitations,

* military population of concern,