Countermeasures against biological and chemical warfare

Issue 0

The war in Iraq has highlighted again the so-called ‘weapons of mass destruction’ and their possible use by terrorist groups. Saddam Hussein was thought to possess both chemical and biological weapons that fall into this category, although nuclear warheads (the real weapon of mass destruction) were unlikely.

While certain biological weapons could be construed as having a mass effect, chemical agents are much less limited in effectiveness.
Chemical warfare agents
Chemical warfare agents in the form of mustard gas have their origin in the 1st World War. The technology for their further development improved dramatically in the following decades and there are now four main groups of gases (see Table 1) referred to as nerve, blister, blood and choking agents. Note that chlorine is listed amongst the latter and can be easily made by mixing common swimming pool treatment chemicals.
Table 1. The more common chemical warfare agents
Table 1. The more common chemical warfare agents
The nerve agents are the most deadly and Vx can be taken as typical. Vx is absorbed through the eyes, skin as well as inhalation, so a respirator on its own is totally ineffective. Vx has been referred to as the deadliest nerve agent ever created and while antidotes are available, without these death can occur within minutes. Initial symptoms include nausea and vomiting, severe difficulty in breathing, slurred speech and increased heart rate. This develops into convulsions and coma followed by complete fatigue of the nervous system and the stoppage of breathing.
Mustard gas is much less lethal but has long term effects. Again it can be absorbed through the eyes, skin and inhalation. Inhalation results in heavy coughing that causes massive and painful damage to airways. Skin contact results in extremely severe blisters and burns. Long term effects include chronic respiratory diseases, cancer, birth defects and chronic eye problems. There is no specific antidote for blister agents.
Teargas (CN or CS) is not classified as a chemical warfare agent but possesses many similarities. It has to be inhaled, but it also makes the eyes run, and is used to train military personnel in the use of respirators. Many countries are however reconsidering the use of teargas for crowd or riot control, as it is not 100% safe and could be life threatening for infants as well as people with asthma and or lung diseases. Teargas has also proved to be fatal if used in confined spaces. It is interesting to note that in 1969 80 countries voted to include teargas agents among the chemical weapons banned under the Geneva Protocol.
It is perhaps amusing to note that in the aftermath of 11 September there was a rush in North America for people to buy gas masks. The term gas mask is incorrect and the breathing device required is actually called a respirator. These devices have a strict shelf life after which they will become ineffective and even more critical is the carbon impregnated filter. The devices that can be bought from your local army surplus store will be well past their use-by date and may provide no protection. Also, the respirator only protects against agents that are inhaled. Many nerve agents only need contact with exposed skin. Normal clothing will be penetrated by these agents and soldiers wear suits impregnated with activated carbon as well as butyl gloves and boots together with the respirator.
In a hot climate like we have in South Africa, chemical warfare agents are not as effective as they rapidly evaporate in heat and one way to decontaminate vehicles is a system developed by a local company that operates like a giant hair dryer. The agents are much more effective and dangerous in cold or freezing weather where they can freeze on contact with the ground and then are released when the temperature eventually rises.
Apart from the widespread use of mustard and other chemical warfare agents in the Iraq/Iran conflict, and against the Kurds1, the only publicised attack on civilians came in 1995 with the incident on the Tokyo subway in Japan. The agent used here was Sarin and the effect was much more widespread than revealed at the time. Traces of Sarin were widely distributed over the underground railway network being probably transferred on the feet and clothes of commuters. Taken by surprise and not knowing what it was, resulted in victims being initially placed next to the outlets of the ventilation system, resulting in further contamination. A further mistake was the multiple use of ambulances without intermediate decontamination.
It has become standard practice now to deploy networked chemical warfare agent detectors at major events such as the Olympics. This took place on a major scale in Sydney, and Athens is expected to be the same. South Africa also deployed detectors during the recent World Conference. Police on the London Underground are also equipped with detectors and are trained to cope with a chemical attack.
Biological weapons
When it comes to biological warfare agents most people today think of anthrax as a result of its use in North America post 11 September and the dozens of harmless white powder incidents worldwide. Anthrax falls into the bacteria category which also includes the even more frightening Bubonic Plague (Black Death) that killed millions in Europe during the fourteenth century. Unlike anthrax the Bubonic Plague is highly contagious and is lethal if untreated.
Besides bacteria one has also to consider viruses which include the highly contagious and now eradicated smallpox. Another substance has also been in the news and that is Ricin, which is a toxin and is usually administered by injection. Another toxin which is dangerous is that which causes botulism. While antibiotics and vaccinations are effective in the fight against biological warfare the danger is that there might not be enough available for all those affected. Smallpox is a case in point and stockpiles of vaccines are small because this disease has effectively been eradicated.
Remember that apart from direct delivery of anthrax spoors through the post they could also be introduced through a building's airconditioning inlet. The most effective way to use other bacteria and viruses would be the mass contamination of water or food supplies.
While chemical warfare agents can be readily detected and identified using handheld or portable electronic devices, the identification of biological agents remains elusive, and typically requires in-depth analysis by a forensic laboratory. There are some devices now available that can provide a 90% reliable answer in less than 20 minutes for both viral and bacterial pathogens. As it is not 100% reliable it would probably not eliminate the need for quarantining, but identification of the suspected virus or bacteria would allow proper treatment of those affected to be initiated.
Summary
In these days of asymmetric terrorism anything is possible, including the use of a small nuclear device. However, not all terrorists are martyrs and the use of a chemical device is much more likely than a biological weapon that will spread like wildfire and have no respect for the terrorist or his friends.
In the event of a chemical attack there are some simple guidelines to use. A handkerchief over the face is better than nothing, and unlike a fire always try to move higher. If you are in a subway or underground move towards the surface and in a stadium do not follow your instinct to run for the stairs down, but move further up the stand. Forget about buying that military surplus gas mask as it will probably be less effective than your hanky and do not follow the American and Israeli example of trying to duct tape all your doors and windows. Military armoured vehicles such as those used by the Coalition Forces in Iraq are sealed but this is maintained by creating an overpressure with air drawn in and purified by a very special activated carbon filter. Devices in these vehicles monitor the air inside and out for the presence of chemical warfare agents. If the vehicle skin is breached then full protective gear, including respirators, is donned.
1. The worst recorded attack was in March 1988 in the Kurdish village of Halabja where a combination of mustard gas, Sarin and possibly Vx killed at least 5000 people and left more than 65 000 others with severe skin and respiratory disorders.



 

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