Defense Against Toxic Weapons: Introduction

Defense Against Toxic Weapons: Introduction

by David R. Franz

Defense Against Toxic Weapons

INTRODUCTION

The purpose of this manual is to provide basic information on biological toxins to military leaders and health-care providers at all levels to help them make informed decisions on protecting their troops from toxins. Much of the information contained herein will also be of interest to individuals charged with countering domestic and international terrorism. We typically fear what we do not understand. Although understanding toxin poisoning is less useful in a toxin attack than knowledge of cold injury on an Arctic battlefield, information on any threat reduces its potential to harm. I hope that by providing information about the physical characteristics and biological activities of toxins, the threat of toxins will actually be reduced. I did not intend to provide detailed information on individual threat toxins or on medical prevention or treatment. This primer puts toxins in context, attempts to remove the elements of mystery and fear that surround them, and provides general information that will ultimately help leaders make rational decisions, protect their soldiers and win battles.

The mission of the U.S. Army Medical Research and Development Command's Medical Biological Defense Research Program is to study and develop means of medically defending the U.S. Armed Forces from toxins and infectious threats posed by adversaries. It is our responsibility to develop medical countermeasures to toxins of plant, animal and microbial origin. We believe that there is a biological toxin threat and we know of countries that are not in compliance with the Biological Weapons Convention of 1972. Therefore, prudence mandates a strong defensive program. The toxins described herein are all nonreplicating agents; some have been identified by the intelligence community as biological warfare threats.

Physical measures, such as the protective mask and decontamination systems, developed for the chemical threat are, for the most part, effective against toxin threats. Research to develop individual medical countermeasures to toxins is complicated by several factors. A number of toxins could be selected by an adversary for use in low-tech, relatively inexpensive weapons. Many more are potentially available through genetic engineering or chemical synthesis. Biological weapons are far more easily obtained and used than nuclear weapons. They actually may be more easily produced and used than conventional explosive weapons. Colorless, tasteless, odorless, small-scale aerosols may be generated relatively easily with a cheap plastic nebulizer attached to a pump or pressurized air bottle. However, production and use of toxins as true mass casualty weapons is not a trivial undertaking.

The likely route of intoxication for soldiers or victims of terrorist attack is through the lung by respirable aerosols; another possibility is through the gastrointestinal tract by contamination of food or water supplies, although the latter would be difficult in chlorinated water, or in rivers, lakes or reservoirs because of dilution effects. The effects of most toxins are more severe when inhaled than when they are consumed in food or injected by bites or stings. Some toxins can elicit a significantly different clinical picture when the route of exposure is changed, a phenomenon that may confound diagnosis and delay treatment. Finally, because the primary population at risk is relatively small (military troops, not the general public, as with childhood infectious diseases), there is little commercial incentive to produce vaccines, antisera or therapeutic drugs to counter toxin threats.

There are still many unknowns regarding toxins and their weaponization. Statements in this document on the nature of a "typical toxin attack" are based on my understanding of the physical characteristics of toxins, recent studies of aerosolized toxins in small laboratory chambers to test protective drugs and vaccines, and historical data from larger-scale studies with toxin or simulant aerosols. The following three descriptions, Toxin, Mass Casualty Biological (toxin) Weapon and Militarily Significant Weapon, define these terms for the purposes of this primer.

1. A Toxin is any toxic substance that can be produced by an animal, plant or microbe. Some toxins can also be produced by molecular biologic techniques (protein toxins) or by chemical synthesis (low molecular weight toxins). Chemical agents, such as soman, sarin, VX, cyanide and mustard agents, typically man-made for weaponization, are not included in this discussion except for comparison.

2. A Mass Casualty Biological (toxin) Weapon (MCBW) is any toxin weapon capable of causing death or disease on a large scale, such that the military orcivilian infrastructure of the state or organization being attacked is overwhelmed. (Note: The commonly accepted term for this category of weapons is "Weapons of Mass Destruction," although that term brings to mind destroyed cities, bomb craters and great loss of life; MCBWs might cause loss of life only. I do not anticipate that "MCBW" will replace the term "Weapon of Mass Destruction" in common usage, but it is technically more descriptive of toxin weapons).

3. A Militarily Significant (or Terrorist) Weapon is any weapon capable of affecting-directly or indirectly, physically or through psychological impact-the outcome of a military operation.