Bioterrorism Watch: Signs and symptoms of chemical exposures

Signs and symptoms of chemical exposures

The following are among the major chemical agents that may be used by a terrorist. As a general rule, health care providers using appropriate personal protective equipment should remove the exposed person from the source immediately, and decontaminate by removing, bagging, and sealing the person’s clothing. Flush the skin with water and then wash with soap. Take care to prevent secondary cases from contaminated clothing, ground, vegetation, or equipment.

Nerve Agents

• Sarin (GB) is a colorless, odorless liquid that mixes readily in water. Sarin can be ingested, inhaled, or absorbed through the skin. Depending on the dose, onset of clinical manifestations can vary from a few minutes to one hour, although most occur within minutes. Signs and symptoms include visual disturbance, runny nose, chest tightness, nausea, vomiting, convulsions, and death. Treatment includes atropine, pralidoxime chloride, and diazepam.

• Tabun (GA) is a colorless-to-brownish liquid. Under average weather conditions, tabun can persist for one to two days. It is primarily released as an aerosol or vapor. Clinical signs and symptoms include visual disturbance, runny nose, chest tightness, nausea, vomiting, convulsions, and death. Treatment includes atropine, pralidoxime chloride, and diazepam.

• Soman is a colorless and tasteless liquid that mixes readily with water. After release, it evaporates rapidly, dissipates, and eventually breaks down in the environment. Clinical manifestations include visual disturbance, runny nose, chest tightness, nausea, vomiting, convulsions, and death. Treatment consists of decontamination; drugs such as atropine, pralidoxime chloride, and diazepam; ventilation to support respiratory function; and supportive care.

• VX is an amber-colored, oily liquid that will remain in the environment until it has been properly cleaned through decontamination methods. VX can enter the body through ingestion, inhalation, or through the eyes or skin. Health effects include constricted pupils, visual disturbance, runny nose, chest tightness, nausea, vomiting, convulsions, and death. Diagnosis is based on history of exposure, clinical signs and symptoms, and confirmatory laboratory tests. Treatment includes atropine, pralidoxime chloride, and diazepam; ventilation to support respiratory function; and supportive care. Because of VX’s persistent characteristics, take special care to prevent secondary cases from contaminated clothing, ground, vegetation, or equipment.

Blister agents

• Mustard (HD) causes severe skin, lung, or eye damage. The health effects of exposure can be delayed up to 12 hours. Those exposed might notice the odor of mustard, which is similar to onion or garlic. Hours after exposure, the skin may appear red. Upper respiratory problems such as difficulty breathing, coughing, painful sinuses, or sore throat may occur. Over a period of hours, small blisters appear and gradually combine to form large blisters. Mustard exposure can be confirmed through a urine test. There is no antidote for mustard exposure.

• Lewisite is a blister agent that produces immediate effects. Its vapor causes burning or pain in the eyes, nose, and skin. Fresh air can increase the pain. Lewisite also may produce visible tissue damage within several minutes of contact. Later, severe damage to the skin, eyes, or airways may occur. Lewisite is diagnosed by recognizing its clinical manifestations (immediate pain or irritation of skin and mucous membranes). Other signs and symptoms that may occur later are skin flushing, blisters on the skin, and eye and airway damage. Treatment consists of decontamination, the use of the antidote British Anti-Lewisite (BAL), and supportive care.

Pulmonary agents

• Phosgene (CG) has the odor of newly mowed hay. This highly toxic substance immediately irritates the eyes, nose, and skin. It also produces tissue damage within several minutes of contact. Phosgene exposure is diagnosed by recognizing the signs and symptoms (eye and airway irritation, difficulty breathing, chest tightness, and delayed pulmonary edema). There is no specific antidote for phosgene. Decontaminating all exposed areas is the most effective means of decreasing tissue damage.

• Cyanide is a colorless liquid that prevents cells from using oxygen, which results in death. Inhalation is the primary mode of exposure. Cyanide in moderate amounts may produce headache, nausea, dizziness, weakness, or anxiety. A large amount of cyanide will produce loss of consciousness within seconds, and death may occur within minutes. Cyanide exposure is diagnosed by the clinical signs and symptoms suggestive of inadequate oxygen. Successful treatment for acute cyanide poisoning depends upon rapid treatment with oxygen and the use of antidotes (amyl nitrite, sodium thiosulfate, and sodium nitrite).

• Chlorine is a greenish-yellow gas with an irritating odor. It is a potent irritant to the eyes and skin. Exposure also causes severe pulmonary irritation that may result in death. Chlorine exposure is difficult to diagnose. There is no specific antidote. Remove from the source and provide fresh air. If eyes or skin were exposed, rinse them with plenty of water. Provide oxygen if there is shortness of breath or difficulty in breathing.

Source: Centers for Disease Control and Prevention, Atlanta.