The Chemical/Biological Threat: Part 1 Chemical Threats

• By Michael Dorn
• 01/01/04

Since September 11, many people have expressed concern about the dangers of chemical and biological terrorism. Many consultants have developed school emergency operations plans that provide one protocol for both chemical and biological incidents, when there are in fact very distinct differences between the two. Understanding these differences is crucial in order to prevent, mitigate against and prepare for incidents of either type. This column will provide a basic understanding of chemical weapons concerns. I am in no way predicting either type of attack on a school, only trying to help school officials correct the deficiencies in many safe school plans that are now in place. We must also be mindful that schools, school bus routes or a school event could be incidental targets when another primary target is hit.

In February I will examine the dangers of biological threats. Both columns will rely heavily on Jane’s Chemical – Biological Defense Guidebook, which is by far the most comprehensive and respected book on the topic. My editors at Jane’s were kind enough to provide me with a copy of the $1,200 book, and to grant me permission to use it as source material for these columns.

The use of chemical weapons dates back to 2000 BC when“toxic fumes” were employed in India. In more modern times, they have been used in a number of incidents by military forces. Terrorists and others have also made use of chemical weapons in attacks like the poorly executed, but still deadly and disruptive sarin nerve agent attack on Tokyo subway systems in 1995.

Mass casualty, no-notice chemical attacks are categorized by most experts as low probability but high consequence events. They have many characteristics that differentiate them from biological attacks. The first major difference is that chemical attacks are easier to carry out because it is less difficult to acquire and use many types of dangerous chemical substances than it is to gain access to such biological weapons such as anthrax or smallpox. In a no-notice chemical attack, indications of an attack are typically seen close to the site and time of the attack. Most chemical weapons that are likely to be used produce immediate symptoms in those who are victimized, in contrast to many types of biological attacks where indications of a no-notice attack typically begin to appear over a greater time frame and often in places remote from the actual attack site.

In chemical attacks, the initial response is more prone to be made by emergency response personnel who are summoned to the vicinity of the attack(s), whereas the response for biological events is more apt to involve medical and public health officials, with the response hopefully being identified through a coordinated public health surveillance network. Action steps in the emergency operations plan will typically need to address such measures as sheltering in place, mass decontamination of victims and the rapid establishment of exclusion zones.

There are a variety of substances that could be used for a chemical attack, ranging from readily available pesticides or substances like cyanide, to deadly nerve agents that are often much harder to acquire, such as sarin, tabun or soman. There are also a variety of attack methods that can be used effectively under a wide range of weather conditions. As chemical attacks — particularly those involving fast-acting nerve agents — produce more rapid onset of symptoms, the emergency medical response must be immediate and effective to minimize the severity of the harmful effects on victims. These types of incidents also require a very careful response by public safety officials to prevent responders themselves from becoming victims, as happened in the Tokyo subway attacks.

The competing demands of time and the need for precautions in the response pose extreme challenges to emergency response personnel. Additionally, it is of critical importance that responders quickly identify the likely agent used to facilitate more effective emergency medical care. Fortunately, the ability of emergency response agencies to address this type of attack have been steadily increasing in recent years through a massive influx of new equipment and superior training of personnel. Far more public safety agencies now have, or are obtaining, advanced training, protective equipment and devices used to identify deadly chemicals in the field.

Understanding the threat of chemical weapons is the first step in deciding what actions are realistic. Local, state, and federal agencies and qualified consultants can provide more detailed and specific guidance as needed. As with other safety efforts, antiterrorism measures should be driven by a formal risk and vulnerability assessment process. Fortunately, you have many valuable allies in the fight against terrorism, now is a good time to draw on their expertise.