The Psychological Considerations of Chemical and Biological Weapons

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Both civilian and military researchers have well-studied the psychological effects of natural disasters on civilians and the effects of combat on soldiers. Yet, little attention has been given to the psychological effects of the deployment of chemical or biological weapons on the general public or first responders.

While first responders and search and rescue personnel would likely be overwhelmed with treating the actual physical casualties of biological and/or chemical weapons, past experience has shown that the presence of those who would experience adverse psychological reactions is extreme and could seriously disrupt the treatment of those actually suffering life-threatening injuries.

This paper offers an examination of human behavior in such crises as well as recommendations for the treatment of the so-called “walking worried,” who suffer from the uninformed and irrational psychological consequences of such attacks. It also shows that the success of chemical and biological weapons for military use has been insignificant, and is likely a reason why their use by terrorists to date has been minimal to non-existent.

However, the combination of technological advances now available to terrorists and the very real concerns over the psychological effects resulting from chemical or biological weapon exposure pose a moderate to severe threat to civilian populations and emergency planners.

As such, the implementation of strategies for emergency planners to address the psychological considerations of chemical and biological weapons among civilians and first responders is critical.

Fear is contagious. While it is said that terrorism may kill individuals, it intimidates thousands. Though panic may be the immediate result of a chemical or biological attack, prolonged anxiety among individuals and society as a whole can be crippling.


Chemical weapons are predominantly man-made and can generate effects in victims within hours or days. They are said to be good for use as terrorist weapons because many of the symptoms created by chemical exposure (e.g. hyperventilation, heart palpitation) can be misdiagnosed as “anxiety and fear” by medical providers. This can slow down the detection of the use of chemical weapons. Such misdiagnoses can create increased anxiety and fear among the general public.

With biological weapons, only a small amount is required to infect an individual as the pathogens typically “grow” inside the body. From the time a person is actually infected until the time the pathogen “grows” inside the body and causes the person to be become symptomatic is called the “incubation period.”

It is this incubation period that makes the mass use of biological weapons particularly fearful. It can often be several days or weeks before victims begin to show signs of exposure. Not only could it be several more weeks before medical providers are able to acquire sufficient prophylactic medications for infected persons – and vaccines for the non-infected – many of the infections from biological weapons can travel from person to person, or through contaminated food.

We can easily see how this would not only create fear and panic among the general population, it could disrupt and overwhelm the medical community. Keep in mind too that in the several days or weeks that it may take for authorities to discover that there has actually been a biological event, the terrorists would be long gone, avoiding detection and arrest.

Surprising to most, history has shown that biological agents are very ineffective as military weapons and chemical weapons have only limited use. However, we have seen that chemical and biological weapons can be very effective weapons of terror against civilians, “by inducing fear, confusion and uncertainty in everyday life”.

Mathewson (2014) categorizes terrorist attacks into three phases: (1) the Pre-attack Phase, (2) the Acute Event Phase and (3) the Consequence Management and Reconstruction Phase.

The Pre-attack Phase is the period prior to an actual attack. It is during this phase that organizations (military, communities, schools, etc.) should conduct ongoing assessments and judge their vulnerabilities. While the military and law enforcement most often do well to prepare during this phase, many local community leaders and even individual citizens do not.

The Acute Event Phase consists of immediate response to an actual terrorist event and strategies learned in the Pre-attack Phase are implemented. These strategies will include fire suppression, search and rescue and emergency medical efforts. Obviously, planning during the Pre-attack Phase helps mitigate damage during the Acute Event Phase.

The final Consequence Management Phase is the actual time for reconstruction. It is during this phase that communities, health care providers and individual families will confront those suffering from frustration, anxiety, grief and mourning, as well as sleep disorders, memory problems and varying degrees of depression.

Even anxiety experienced in the Pre-attack Phase can result in some psychological response, but it is the trauma experienced during the Acute Event Phase of a chemical and/or biological event that can lead to an array of psychological responses during the Consequence Management Phase.

It is estimated that between nine and 35 percent of persons directly exposed to all traumatic events develop significant post-traumatic psychological distress and perhaps even post-traumatic stress disorder (PTSD).

Studies show that human-made disasters can be even more psychologically impairing than natural disasters. Terrorism may be the most pathogenic due to its unpredictable and unrestrained nature (Mathewson, 2014).

Perhaps even more profound, the discovery of an actual chemical or biological attack “could generate a disproportionate public response because of a broad public perception that their use is akin to poisoning”.

While panic may be the immediate result of a terrorist attack, prolonged anxiety among individuals and society as a whole can be crippling.


German prisoners wear gas masks in Ypres, France in an April, 1915 file photo.

German prisoners wear gas masks in Ypres, France in an April, 1915 file photo.

During the Trojan War in 431 BC, the Greeks used mixtures of sulfur and pitch resin to produce suffocating fumes against the Trojans. Since then, chemical and biological weapons have been used in a number of conflicts.

At the Battle of Ypres, Belgium in April 1915, the Germans used chlorine gas against the French, killing 5,000 and injuring 15,000. Throughout World War 1, chemical agent sulfur mustard (mustard gas) caused some 400,000 casualties, more than any other chemical agent. All total, during World War II, an estimated 124,000 tons of chemicals were used by all parties.

From 1978 to 1980, Rhodesian and South African forces poisoned waterways with Anthrax, infecting thousands of cattle, causing a critical food shortage in the area. Over 10,000 people contracted the disease, resulting in 182 deaths.

In 1979, in Sverdlovsk, Russia, 94 people became sick with gastrointestinal anthrax – resulting in 64 deaths – from what the Russian government blamed on contaminated meat. It was later discovered that the outbreak was related to a faulty exhaust filter at a nearby military facility.

During the Iran-Iraq war (1980-1988), Saddam Hussein used chemical weapons on Iraqi civilians and Iranian soldiers. Although, of the 600,000 Iranians killed during that war, less than one percent (5,000) died from chemical weapons.

In the mid-1990s, the Aum Shinrikyo cult in Japan made several unsuccessful attempts to release anthrax in Tokyo. While local residents reported foul smells, brown steam and pet deaths, the strain of anthrax deployed was a weak vaccine strain and caused no human deaths.

Surprising to most, history has shown that biological and chemical weapons have actually limited or no effective use as military weapons. As for chemical weapons specifically, Harigel (2001) wrote, “it is difficult to see why they are around in the first place.”

We have seen though that they can be very effective weapons of terror against civilians.


We can classify several types of traumatic events, including: (1) natural disasters, like earthquakes, hurricanes and floods, (2) accidental disasters, like vehicle and airplane accidents, and (3) deliberately man-made disasters, including school shootings, arson and terrorist activities.

In the aftermath of disasters, we find that communities can – at least temporarily – become more cohesive, with neighbors acquiring a more firm sense of “community” and “helping out” other neighbors.

Still, studies show that mass violence – such as terrorist attacks – can be psychologically more severe than others types of disasters, resulting in as many as 67% of those exposed suffering from some degree of psychological impairment. The medical community has come to call this group of psychological casualties “the walking worried,” as they only “think” they are suffering from the effects of possible chemical or biological attacks.

Studies show that these “walking worried” can overwhelm medical resources, further complicating local efforts to deal with scarce resources in times of disaster.

On March 28, 1979, in Pennsylvania, residents dealt with a series of problems at the Three Mile Island (TMI) nuclear reactor, Studies show that those who lived near the reactor reported increased anxiety and psycho-physiological problems up to five years after the containment and cleanup of TMI with symptoms “characterized as chronic stress syndromes.”

While this was a technological disaster – rather than one involving terrorists’ use of chemical or biological weapons – it shows the uniqueness of how humans deal with “exposure” to foreign materials.

In June 1987 – during the 1980-1988 Iran-Iraq War, Saddam Hussein deployed mustard gas against the Iranians and some 4,500 of the 12,000 civilian residents of Sardasht were exposed. While most received mild exposure and were treated as outpatients, some 1,500 developed moderate to severe symptoms requiring hospitalization. Years after the attack, residents still held that the deaths from the chemical attacks were more horrific than deaths from conventional weapons. Those under the age of 19 at the time of the attacks suffered more severe psychological effects.

When Saddam Hussein deployed SCUD missiles against Israeli civilians during the first Gulf War, there was clearly a “threat” of chemical or biological attack, but there were no actual reports or evidence of these agents being used. Still, 27% of Israeli civilians admitted to hospitals during the attacks had mistakenly injected themselves with Atropine antidotes and 43% were diagnosed as “psychological casualties”  Palmer notes that “about 75% of the casualties resulted from inappropriate actions or reactions on the part of victims.”

One study found a 250% increase in the risk for clinical depression among Israeli civilians during the period of the SCUD attacks. It was noted that those at the greatest risk were middle-aged women as well as the less educated.

On March 20, 1995, terrorists placed several bags of the neurotoxin sarin on different trains on Tokyo’s subway system. While only 13 died from the exposure and 1,051 people had medical symptoms indicative of sarin exposure, over 4,500 were treated as “psychological casualties” of the attack. One report showed that as many as 50% of those initially involved still reported physical or mental disability over three years later.

Even further, because it was several hours before officials realized there had been a nerve agent attack, there were no coordinated decontamination efforts. As a result, “135 firefighters and EMS personnel (10% of the responders) suffered secondary contamination and 20% of receiving hospital staff suffered effects from secondary exposure” (Beaton & Murphy, 2014; Shea, 2004). Today, 18% of people in Japan still experience “flashbacks” from the attack (Mathewson, 2014).

Another example is the Oklahoma City terrorist bombing, which resulted in 168 fatalities, but 8,898 individuals pursued counseling crisis intervention or support groups; a ratio of 1:53. Among adult survivors, 45% experienced post-event psychiatric disorders and 34% suffered from post traumatic stress disorder (PTSD).

Of the surviving first responders to the World Trade Center, studies show that 52% still suffer from both mental health issues and respiratory problems (Mathewson, 2014). Of some 10,000 New York firefighters who have “visited” the site of the 9/11 attacks, about 4,000 have reported respiratory difficulties, leading to what has become known as “World Trade Center Syndrome”.

Between 1996 and 2000, there were only 180 anthrax inquiries in the United States. Surprisingly though, from September to October in 2001 – in the immediate aftermath of the 9/11 attacks – there were a staggering 7,000 reports regarding anthrax. The existence of such a dramatic shift in anthrax reporting can be directly contributed to the psychological effects of the anthrax mailings which occurred in the weeks after the 9/11 attacks. Such a drastic reaction of the public should be a significant consideration for medical personnel, first responders and emergency planners.


While first responders are certainly susceptible to the same psychological responses to chemical and biological weapons as the general population, there is some evidence that their training can serve as a buffer (of sorts) leaving them better prepared to cope.

Fear of chemical and biological weapons (or other tragic, fearful events and weapons) may itself be associated with several epidemics of medically unexplained illnesses. Among our military troops, we have seen several chronic phenomena relevant to exposure and related symptoms, including Atomic Veterans Syndrome, Agent Orange Syndrome, and Gulf War Illness. Although, in many cases, we can see that media hype and misinformation have distorted even these syndromes.

Agent Orange has been said to cause increased risk of cancer among veterans and birth defects in the children of veterans exposed to this agent in Vietnam. Studies by the Centers for Disease Control (CDC) found no evidence of this to be true. However, this group does suffer from increased rates of anxiety, alcohol abuse and PTSD.

For emergency medical department personnel, radiological weapons and even “dirty bombs” will be easier to deal with than chemical or biological weapons because radioactivity can be measured more readily than nerve agents or vesicants. Emergency medical personnel may be contaminated by chemical or biological agents as they arrive on scene of an event, or as contaminated patients arrive in emergency rooms. Once it is discovered that one of these agents has been deployed, emergency personnel would likely then be overwhelmed with the “walking worried”.

First responders can be very reluctant to ask for help, increasing their risk of later exacerbating any psychological injury. This is why first responder personnel should be on the lookout for stress indicators among their co-workers.

All of these factors increase our anxiety, fear and uncertainty over chemical and biological weapons. Shea adds that “the wide array of potential symptoms from chemical, biological and toxin weapons make identification of the causal agent difficult and complicates treatment.”


Uncertainty is the primary driver of fear in the event of chemical or biological weapons. This makes the use of these weapons a concern for government officials, an attractive weapon for terrorists and front page news for the media.

As the media headline these attacks, associated hysteria can easily translate to communities not directly affected. It is important that media-types provide clear, reliable information in a timely manner and – during the Emergency Management Phase of an attack – be sure to differentiate opinion from reporting.

Another factor related to these kinds of attacks involves false alarms. In the Gulf War there were some 4,500 false alarms and some 2,300 false anthrax alarms during the first two weeks of the anthrax mailings.

Lack of trust in both the government and media could heighten reaction to these attacks. After these types of attacks, the public can blame authorities for their being unable to protect the citizens.

During a chemical or biological attack, the psychological casualties will almost always outnumber the physical casualties. The “walking wounded” could overwhelm medical personnel and local emergency planners, further complicating emergency efforts, leading to increased public hysteria.

Today’s military medical personnel use morbidity reports and statistics dating from as early as World War II to assess the possibility of battle fatigue and combat stress syndrome on soldiers. They can estimate how many psychological casualties or “walking worried” they will have depending on the number of actual “physical casualties” in any given conflict or engagement. For example, if a combat unit receives 10 physical casualties, we can use a ratio of 1:10 to predict that we will likely receive 100 psychological casualties (although the ratio could be 1:5, 1:15, etc.). Local, civilian emergency planners would do well to use this same type of planning.

Planners should remember that – after a chemical or biological attack – there is no time sheet to anticipate when psychological symptoms will begin to appear, or to what extent they will appear in any given person. An individual’s past experience with traumatic events could help or hinder recovery. Individual strengths or weaknesses will be a determining factor, as well as the degree to which that person has suffered personal loss as a result of the attack.

Emergency planners should consider that large scale panic is actually not very common in human beings, even when in groups. Of course, this applies until an individual or group perceives immediate threat of death or grave bodily injury. History has shown that – even during times of war or raid – the vast majority of people were able to cope well. Many communities even experienced heightened concern for their fellow man.

First responders and medical planners should remember that – especially following disasters – women experience anxiety, depression and even PTSD at twice the rate of men. After a traumatic event, about eight percent of men and 20 percent of women will develop PTSD. However, men in general and first responders are more likely to deny symptoms, or that they need help. Lastly, fire fighters and rescue workers have higher rates of alcoholism and their alcohol intake tends to increase under extreme stress.

After a chemical or biological attack, medical personnel should remember that it will be difficult to separate those suffering actual exposure symptoms from those exhibiting unexplained medical illnesses as a result of “perceived” exposure. These “walking worried” will complicate medical response, especially if there is government effort to quarantine individuals, which will further heighten public anxiety.

For emergency planners, realistic training is a must. Unfortunately, while many local services provide training on emergency response and the treatment of physical casualties, the treatment of psychological casualties is seldom addressed.

KeithPoundsKeith Pounds is a former hospital corpsman (medic) having served in the U.S. Navy and with the Marines. He holds an MBA with a concentration in organizational psychology and is the president and CEO of Countercon, a Columbia, S.C.-based counterterrorism consulting company. In 2012, he was designated as an Honorary Green Beret by the S.C. Chapter of the Special Forces Association.


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Keith Pounds is a veteran of the U.S. Navy having served as a hospital corpsman. He holds a Masters's degree with a study concentration in organizational psychology.

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