Intended for healthcare professionals


Psychological implications of chemical and biological weapons

BMJ 2001; 323 doi: (Published 20 October 2001) Cite this as: BMJ 2001;323:878

Long term social and psychological effects may be worse than acute ones

  1. Simon Wessely, professor (s.wessely{at},
  2. Kenneth Craig Hyams, chief consultant, Occupational and Environmental Strategic Healthcare Group,
  3. Robert Bartholomew, researcher
  1. Department of Psychological Medicine, Guy's King's and St Thomas' School of Medicine and the Institute of Psychiatry, London, SE5 8AF
  2. Office of Public Health and Environmental Hazards, Department of Veterans Affairs, 810 Vermont Avenue NW, Washington DC 20420, USA
  3. Department of Sociology, James Cook University, Townsville 4811, Queensland, Australia

    The ostensible purpose of chemical and biological weapons is to endanger lives. Biological agents, however, are particularly ineffective as military weapons, while chemical weapons have only limited uses. This may be why armies have generally acquiesced in international treaties to contain these unpredictable weapons and feel capable of waging war without them. Instead, chemical and biological weapons are quintessentially weapons of terror. The now routine journalistic association between chemical and biological weapons and the word terror confirms that the purpose of these weapons is to wreak destruction via psychological means—by inducing fear, confusion, and uncertainty in everyday life. 1 2 These effects will take two forms, acute and long term. It is customary to expect largescale panic if such weapons are ever effectively deployed or thought to be deployed.

    We do not, however, know whether such panic would materialise. Media stories emerging from the United States in the past few days are not encouraging, but we should remember that history teaches us that civilian populations have been able to withstand previous “terror” weapons such as aerial bombing, despite warnings to the contrary. However, one psychological reaction that can be anticipated, because it has already started to materialise, is mass sociogenic illness. On 29 September 2001 paint fumes set off a bioterrorism scare at a middle school in Washington state, sending 16 students and a teacher to the hospital.3 On 3 October over 1000 students in several schools in Manila, Philippines, deluged local clinics with mundane flu-like symptoms such as cough, cold, and mild fever after rumours spread via short text services that the symptoms were due to bioterrorism.4 On 9 October a man sprayed an unknown substance into a Maryland subway station, resulting in the sudden appearance of nausea, headache, and sore throat in 35 people. It was later determined that the bottle contained window cleaner.5

    Examples of mass sociogenic illness remind us of the dangers of inadvertently amplifying psychological responses to chemical and biological weapons and thus adding to their impact. One example is the routine use of investigators clad in space suits to assess possible terrorist attacks. Another is that the United States government is considering placing detectors to identify chemical warfare agents on the Washington DC subway system. It is possible that these alarms will in practice cause greater disruptions to transport systems than the attack itself, given the high probability that such detectors may give false alarms. There were 4500 such alerts in the Gulf war and none was associated with a confirmed attack.

    The long term social and psychological effects of an episode of chemical or biological attack, real or suspected, would be as damaging as the acute ones, if not more so.6 For example, a serious physical impact of the accidental discharge of sarin nerve agent during the destruction of an Iraqi weapons depot after the end of the Gulf war has not been documented, but the psychological, social, and political consequences have been substantial and continuing.7 Even if the short term consequences of an attack with chemical or biological weapons turn out to be less than some of the apocalyptic scenarios currently being aired by the media, the long term disruptions may be worse than anticipated. Experience from other incidents involving confirmed or alleged incidents of toxic contamination suggests that these might cluster around four major health concerns: chronic injuries and diseases directly caused by the toxic agent; questions about adverse reproductive outcomes; psychological effects; and increased levels of physical

    The general level of malaise, fear, and anxiety may remain high for years, exacerbating pre-existing psychiatric disorders and further heightening the risk of mass sociogenic illness. 11 12 The current uncertainty over the chronic health effects of low level exposure to toxic agents will further increase anxiety in the affected communities.13 Because health officials cannot provide blanket assurances that no harm will result from brief or non-symptom producing exposure to toxic agents, frustration and then a growing distrust of medical experts and government officials may result, robbing state institutions of the trust they need to manage recovery. Lastly, unconfirmed or controversial hypotheses about the health effects of exposure to chemical and biological weapons will probably become contentious scientific and media issues in the years ahead, as has occurred after numerous chemical and radiological incidents, the Gulf war, and the Balkans deployment. 14 15


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