Emergency responders to a chemical attack.

Chemical & Biological Weapons

Chemical Agents

Chemical warfare agents are poisonous vapors, aerosols, liquids or solids that have toxic effects on people, animals or plants. They can be released by bombs, sprayed from aircraft, boats or vehicles, or used as a liquid to create a hazard to people and the environment. Some are odorless and tasteless. They can have an immediate effect (a few seconds to a few minutes) or a delayed effect (several hours to several days). While potentially lethal, chemical agents are difficult to deliver in lethal concentrations. Outdoors, the agents often dissipate rapidly. Chemical agents are also difficult to produce.

There are six types of agents:

Lung-damaging (pulmonary) agents such as phosgene,
Cyanide,
Vesicants or blister agents such as mustard,
Nerve agents such as GA (tabum), GB(sarin), GD (soman), GF and VX,
Incapacitating agents such as BZ, and
Riot-control agents (similar to MACE).

Biological Agents

A terrorist incident involving a biological agent has the potential to cause a widespread medical emergency. The most likely bioterrorist scenario is a covert incident; that is, the biological agent will be released without warning or claim of responsibility. Because many biological agents produce effects that initially appear to be normal flu symptoms, the true nature of an attack may go undetected for a while. In most cases, there probably will be no identifiable crime scene, no explosion and no fire.

In this scenario, detection of a bioterrorism incident will occur as increasing numbers of infected people seek medical care, and alert medical personnel and public health practitioners recognize that an unusual event is happening and report it to their response partners. Thus, it is likely to be medical detection and diagnosis, with the emergence of unusual patterns of illness which will trigger an investigation into the possibility of a terrorist incident.

Meanwhile, the disease may spread well beyond the initial point of attack, either through contagion or through movement of the biological agent itself. If the release is overt, the event may unfold more quickly, but serious health effects and public requests for information and treatment may still overwhelm the system. Biological agents are organisms or toxins that can kill or incapacitate people, livestock and crops. The three basic groups of biological agents which would likely be used as weapons are bacteria, viruses and toxins.

Bacteria - Bacteria are small free-living organisms that reproduce by simple division and are easy to grow. The diseases they produce often respond to treatment with antibiotics.
Viruses - Viruses are organisms which require living cells in which to reproduce and are intimately dependent upon the body they infect. Viruses produce diseases that generally do not respond to antibiotics. However, antiviral drugs are sometimes effective.
Toxins - Toxins are poisonous substances found in, and extracted from, living plants, animals or microorganisms. Some toxins can be produced or altered by chemical means. Some toxins can be treated with specific antitoxins and selected drugs.

Most biological agents are difficult to grow and maintain. Many break down quickly when exposed to sunlight and other environmental factors. Others, such as anthrax spores, are very long lived. They can be dispersed by spraying them in the air or infecting animals which carry the disease to humans as well through food and water contamination.

Aerosols - Biological agents are dispersed into the air, forming a fine mist that may drift for miles. Inhaling the agent may cause disease in people or animals.
Animals - Some diseases are spread by insects and animals, such as fleas, mice, flies, and mosquitoes. Deliberately spreading diseases through livestock also is referred to as agriterrorism.
Food and water contamination - Some pathogenic organisms and toxins may persist in food and water supplies. Most microbes can be killed and toxins deactivated, by cooking food and boiling water.
Anthrax spores formulated as a white powder were mailed to individuals in the government and media in the fall of 2001. Postal sorting machines and the opening of letters dispersed the spores as aerosols. Several deaths resulted. The effect was to disrupt mail service and to cause a widespread fear among the public of handling delivered mail.
Person-to-person spread of a few infectious agents is also possible. Humans have been the source of infection for smallpox, plague, and the Lassa viruses.

Methods of Dissemination

Chemical and biological agents can be dispersed in the air we breathe, the water we drink or on surfaces we physically contact. Dispersion methods may be as simple as opening a container, using conventional (garden) spray devices, or as elaborate as detonating an improvised explosive device.

Chemical incidents are characterized by the rapid onset of medical symptoms (minutes to hours) and easily observed signatures (colored residue, dead foliage, pungent odor or dead insects and animals).

Biological incidents are characterized by the onset of symptoms in hours to days. Typically, there will be no characteristic signatures because biological agents are usually odorless and colorless. Because of the delayed onset of symptoms in a biological incident, the area affected may be wider due to the movement of infected individuals.

Potential targets include highly populated areas, enclosed public spaces (e.g. shopping malls, office buildings, sports/entertainment arenas and mass transit), crops and livestock.

Dissemination through the Water Supply

Potential targets include municipal water supply, enclosed water supplies and bottled water processing plants. Your plan should consider the following relevant factors:

Contaminating large municipal water supplies may be difficult because water purification and sterilization processes that typically use chlorine or ozone will kill most biological agents.
Smaller targets (e.g. water supply in a building) can be attacked by introducing an agent directly into the water tank.

Dissemination through the Food Supply

The intentional infection of a food supply (agriterrorism) is a serious concern. For businesses related to agriculture, there is information on the use of biological agents to infect the food supply, see Steps to Protect Your Farm for Pests and Disease (Checklist 15 in Appendix in the Guidebook or on the checklists page of this site).

Potential dissemination devices include aerosols, sprays, crop dusters, and liquid additives.
Potential targets may include food crops and livestock using food processing plants (e.g. dairies, meatpacking); imported foods and food additives and restaurants.

Prevention

Prevention is key to minimizing risk. Measures to prevent those who have been exposed from developing an infection include the following methods.

Barrier protection (e.g. use of protective suits or sealed buildings to prevent the intake of contaminated air).
Sterilization and disinfection (using chemicals, heat, irradiation, filtration to kill pathogens or reduce their numbers to safe limits).
Public health hygiene and personal hygiene (e.g. soap and water).
Processing food to kill pathogens or inactivate toxins.
Vaccination to create immunity to the disease.

In the event of a terrorist incident involving an infectious biological agent, certain workers may be at risk of infection.

First Responders (police, fire, EMS) who transport ill patients to medical facilities.
Health care workers who care for patients.
Laboratory personnel who handle clinical specimens.
Health department staff who visit patients during outbreak assessment or control.

Because bioterrorism attacks may be covert, these workers may be unaware of the presence or nature of a biological agent. Therefore, workers need to use standard prophylactic precautions (disposable gloves and gown, immediate hand-washing and face shield) to protect themselves when in contact with broken or moist skin, blood or body fluids. Protective gear must be changed between patients to prevent transmission.

Persons affected by biological or chemical agents require immediate attention by professional medical personnel. If medical help is not immediately available, decontaminate yourself and assist others. Decontamination procedures are listed in the checklist, "Checklist to Prepare and Respond to a Chemical/ Biological Attack" (Checklist 23 in the Guidebook or on the checklists page of this site).