Introduction

Weapons of mass destruction (WMD) include chemical, biological, and radiological agents with the potential to cause death at low doses and with serious long term health effects in survivors. This article provides general information relevant to all situations, from terrorist attacks in developed countries to conflict zones in Third World countries. WMD agents can be used to terrorise or subjugate populations and wreak economic damage. Many agents are cheap to produce and can be deployed in different ways. As well as overt use, such as in bombs or by aerial spraying, they can be used covertly such as in packages sent in the post, via animal vectors, or by poisoning of water and food supplies.

Casualties from the attack on Halabja in northern Iraq by the former Iraqi government with multiple WMD agents, including nerve and mustard agents

Threats from WMD

The classic scenario of WMD use against civilians (the basis of many current exercises) is the release of the nerve agent sarin in the Tokyo subway. In this attack the actions of first responders and medical staff helped keep the final fatalities down to 12. Because they lacked protective clothing, however, many of these people absorbed sarin from victims' clothing and developed serious long term neurological complications. Other agents—such as mustard agent, VX, anthrax, and radiation—are more persistent and thus pose greater risks: doses to victims would be higher, attending staff would face protracted periods in protective clothing, and the threat would remain until full decontamination was achieved.

The diversity and gravity of threats are exemplified by the recent anthrax attack on the US Congress through the postal system. It claimed few victims, thanks to rapid intervention by bioweapons specialists, but it paralysed the postal system and cost over $6bn to clean up.

For the past …