Protecting First Responders from Biological Agents

Biological weapons pose a significant threat not only to public health, but also to emergency responders who are trying to assist those directly affected. The use of bio-weapons offers terrorists a low-cost way to carry out an attack against the United States. Such attacks were in fact launched through the U.S. mail system both in 2001 (the anthrax letters that followed the 9/11 attacks against the World Trade Center and the Pentagon) and in 2003-04 (the ricin-infected letters sent to a number of government offices).

Whether an unexpected incident or event seems to be intentional or unintentional, the early detection and surveillance of possible biological agents that might be present is important for quickly and accuratelyentifying the disease process and beginning the necessary response procedures.

In addition to widespread fear and the illnesses that would probably follow a biological attack, evidence of the biological agents themselves may not surface immediately. The symptoms in persons exposed to the agents may not be visible for hours, in fact, or even days. Moreover, after the symptoms do surface, they are often mistaken for influenza. Moreover, the long delay between release of a toxic substance and detection/identification of the agent would provide terrorists additional time to plan and execute their own escape. Another factor to consider is that a major biological attack is likely to overwhelm local medical facilities and could also deplete the stocks of medication and vaccines immediately available and/or quickly replaceable.

Categories of Biological Agents & Various Routes of Transmission

The U.S. Centers for Disease Control and Prevention (CDC) has categorized biological agents – viruses, bacteria, and bacterial-derived toxins – into three main groups: (a) Category A agents – e.g., anthrax, botulism, plague, which pose the highest risk because they can be easily disseminated and quickly spread from one person to another. The result would be high mortality rates and a major impact on public health. (b) Category B agents – e.g., ricin toxin and/or food/water threats such as salmonella and cholera, which also are relatively easy to disseminate. The result here would be a medium risk of illnesses and in most cases a somewhat lower death rate. (c) Category C agents – e.g., emerging pathogens, which in the future may be engineered for mass dissemination and are the most destructive because of their availability, ease of production, and immense potential for widespread illness and death.

Simply being in the vicinity of a biological agent does not necessarily ensure that a person will become ill. In order to affect an individual human being, the agent must actually enter that person’s body. The three principal routes of transmission are: (a) the physical contact of a person with a substance or microorganism; (b) the inhalation of vapors, droplets, or aerosols (particles up to five microns in size may be made into an aerosol and, with the right conditions, can travel distances up to 12 miles and harm anyone in its path); and (c) ingestion of the substance – usually by the consumption of contaminated food or water.

Physical contact, either directly or indirectly, is the most frequent mode of transmission. Direct-contact transmission takes place when a microorganism is transferred directly from an infected person to another person through touch. Indirect contact transmission is when the transfer occurs through use of an intermediary object such as a contaminated needle. Contact also may occur when a microorganism is transmitted by a broad spectrum of “living vectors” such as mosquitoes, flies, or rats.

Some diseases, of course, are capable of being transmitted in more than one way, with each route of transmission creating different symptoms. Anthrax and plague are just two examples of agents that, depending on the mode of transmission used, develop into different forms of the same disease.

Four Levels of Protection & the Three-Ups Rule 

When deliberately used as a biological weapon, an infectious disease can affect a greater number of people in a short amount of time. Obviously, therefore, additional safety precautions are needed to protect first responders themselves from becoming victims of secondary contamination. Fortunately, the Occupational Safety and Health Administration (OSHA) has already defined four levels of protection recommended for the personal protective equipment (PPE) used by responders (and/or other persons likely to be present at the scene of a biological incident or event).

Following, as defined by OSHA, are the PPE specifics: (a) Level A – a fully encapsulated suit fitted with an internal self-contained breathing apparatus (SCBA) – provides maximum protection against most vapor and liquid materials; (b) Level B – a chemical-resistant suit fitted with an external SCBA – offers a high level of protection against oxygen-deficient atmospheres, but a lower level of skin protection; (c) Level C – a chemical suit accompanied by an air-purifying respirator (APR) – can help protect against known hazards (but the APR filter is usually designed to filter only specific chemicals and will not protect responders in oxygen-deficient atmospheres); and (d) Level D – the basic station work uniform – provides only minimal protection. Individual responders, and their supervisors, must take special care in determining and selecting the appropriate level of protection needed for the situation at hand.

Caution also should be used by anyone called to the scene of a multi-casualty incident involving suspicious signs and symptoms, particularly respiratory distress. In addition to staying uphill, upstream, and upwind of the incident site, it is important that responders: (a) be aware of any invisible dangers that may be present; (b) summon trained hazmat teams to the site if there is any suspicion of toxic dangers; and (c) select the correct level of the protective equipment needed.

A final but very helpful rule of thumb also to remember is this: If and when two, three, or more patients are complaining of similar symptoms, that in itself may well be the first clue needed to alert responders to a possible bio-terror event.


For additional information: Department of Homeland Security – National Response Plan, visit

National Library of Medicine/National Institutes of Health Medline Plus – Biodefense and Bioterrorism, visit

Occupational Safety and Health Administration, visit

The Centers for Disease Control and Prevention bioterrorism information, visit

U.S. Food and Drug Administration Bioterrorism and Drug Preparedness, visit

Christina Spoons

Christina Spoons holds a Masters in Public Administration with a concentration in Homeland Security and is currently completing her Ph.D. in the same discipline with a concentration in Terrorism, Mediation, and Peace, both from Walden University. Her emergency services experience includes several years as a Firefighter/EMT and instructor with the American Red Cross. She has been active in the development of firefighter curricula at both the state and national levels and also is involved with several National Fire Protection Association committees, including those focused on Firefighter professional qualifications and electronic safety equipment. She teaches homeland security and public policy and administration courses at Ashford University, and fire science courses at Columbia Southern University.



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