Chemical warfare agents have the potential of being effective weapons for a terrorist attack. They are generally available or easy to manufacture, can be transported and delivered by many means, and their effects can be immediate or delayed. They are also well known, as they were first widely used in warfare during World War I[1].

Nerve agents are the most toxic weapons in the military chemical warfare arsenal. The most common are sarin (GB), tabun (GA), soman (GD), and VX liquid. The G-type agents are colorless, clear, tasteless liquids [2]. GB evaporates at roughly the same rate as water and has no odor. GA has a fruity odor, and GD smells slightly of camphor; both are less volatile than GB [2]. VX is the least volatile agent and is transparent, amber-colored, odorless, and slightly oily. Any of these compounds can cause seizures, apnea, loss of consciousness, and death [1]. They are all in the class of organophosphates and have physiologic effects similar to those seen when household insecticides are sprayed on an insect [1].

Nerve agents are the most toxic weapons in the military chemical warfare arsenal. The most common are sarin (GB), tabun (GA), soman (GD), and VX liquid. The G-type agents are colorless, clear, tasteless liquids [2]. GB evaporates at roughly the same rate as water and has no odor. GA has a fruity odor, and GD smells slightly of camphor; both are less volatile than GB [2]. VX is the least volatile agent and is transparent, amber-colored, odorless, and slightly oily. Any of these compounds can cause seizures, apnea, loss of consciousness, and death [1]. They are all in the class of organophosphates and have physiologic effects similar to those seen when household insecticides are sprayed on an insect [1].

Victims of a nerve agent attack may present with [1,2,3]:

Although the primary diagnosis of a nerve agent attack is made on clinical grounds, the Centers for Disease Control and Prevention (CDC) has established a laboratory network to analyze blood and urine samples to detect the presence of chemical warfare agents [9]. The CDC's Laboratory Response Network for Chemical Threats (LRN-C) designates three levels of laboratories. Level 1 labs are the most secure, have the most specific analytical equipment (apart from CDC labs), and test for exposures to high-threat chemical agents (e.g., mustard agents, nerve agents, toxic industrial chemicals). Level 2 labs maintain testing capabilities for exposures to chemical terrorism agents (e.g., cyanide, toxic metals, some toxic industrial chemicals); level 2 LRN-C methods are customizable and can be readily adapted to detect broad classifications of new and emerging threat agents. Level 3 labs are the most numerous and are able to perform basic tests in addition to providing support with sample logistics and training and research with local hospitals [4].

Atropine, pralidoxime chloride, and diazepam (or other benzodiazepines) are the favored drugs for treatment of nerve agent victims [1]. Atropine blocks the effects of acetylcholine at the muscarinic sites. The drug pralidoxime chloride breaks the bond between the nerve agent and acetyl cholinesterase, allowing the enzyme to become available to break down acetylcholine; however, to be effective it must be administered within minutes to a few hours of exposure, depending on the agent [1,2]. Diazepam has been suggested as the best medication to use for seizures associated with nerve agent attacks. It has also been suggested that diazepam be used in all victims whether they are convulsing or not. These drugs are available in kits, many of which include "autoinject" syringes. The military has used a kit called the Mark 1, which includes atropine and pralidoxime chloride in autoinjectors; up to three Mark 1 kits may be administered as needed [1,10]. The injections must be given in a large muscle, preferably the outer thigh muscle or, alternately, the upper outer buttock in thinly built individuals [10].

There are thought to be five primary ways in which nuclear materials might be used by terrorists. They include [1,5,6]:

In most cases, diagnosing injuries from ionizing radiation requires the history of radiation exposure. There can be instances when a victim is unaware of the cause and presents with a suggestive constellation of signs and symptoms of the prodromal stage of mild acute radiation syndrome (e.g., nausea, vomiting, anorexia) or a more severe syndrome (e.g., diarrhea, cramps, nervousness, confusion) [7]. In addition, there may be some signs that point to radiation injury, such as skin erythema or lesions without history of thermal burns. Unexplained epilation or a sudden drop in leukocytes or platelets could suggest radiation exposure as the etiology [1]. An examination of the blood, urine, or feces can be performed to determine the presence of any radionuclides that may have entered the body.

The immediate treatment for victims of radiologic events includes prompt decontamination. This must be performed prior to the patient entering a care facility to prevent the facility from becoming contaminated. The procedure is similar to decontamination techniques used for chemical weapons, including the removal of clothing, copious washing of the body and wounds, and placing all contaminated items into a closed container.

During the first 8 to 12 hours postexposure, blood samples should be taken for complete blood count (CBC), with attention to lymphocyte count, every two to three hours [7]. In the following two days, repeat CBC every four to six hours. The Andrews Lymphocyte Nomogram is used to ascertain level of injury, with absolute lymphocytes in the 1,000–1,500 range indicating moderate injury, 500–1,000 indicating severe injury, 100–500 indicating very severe injury, and less than 100 indicating lethal injury.

Radiation injuries, traumatic injuries, and burns can occur simultaneously in a nuclear terrorist attack that includes the use of explosives. Because high doses of ionizing radiation can impair healing, a victim who receives high levels of whole-body radiation will usually have a greater degree of total injury, delayed recovery, and probability of death. A patient who has received more than 200 rems should have all major traumatic injuries treated within 48 hours. (Of note, a rem is equal to a rad for gamma rays.) This includes reducing fractures, suturing wounds, treating burns, and performing any required stabilizing surgery. If these interventions cannot be performed within the first two days, any major surgical procedures should be delayed an additional two to three months [1]. Use of burn units is recommended when indicated [7].