War is a disgusting business. If it is possible to rank different forms of warfare on a scale of odium, chemical and biological warfare must be high on the list.
As bad as bombs and bullets are, the idea of people sitting down to design and plan how to use chemicals and microbes to sicken and kill large numbers of human beings is particularly disgusting to contemplate.
Chemical and biological weapons are not an exclusively modern idea, although technology has greatly expanded the scope of these weapons. Before the 20th century such warfare was restricted to activities such as starting fires, poisoning wells, using smoke to confuse enemy troops and distributing smallpox-infected clothing.
Gas-warfare was developed in earnest during the first World War. Lung-irritants such as tear gas, chlorine, phosgene and mustard gas, which causes burns, were widely used to break stalemates in trench warfare.
Between the World Wars, nerve gases such as sarin, which in small amounts can cause paralysis and death, were developed. Gases were widely available during the second World War, but were used only by Japan in China. Although use of deadly gases has been condemned by most countries, such weapons probably remain in most arsenals.
It is said that these weapons were used by Iraq during its war with Iran in the 1980s.
Various chemicals which cause defoliation by interfering with the chemical metabolism of plants, such as Agent Orange, have been used to remove enemy cover in jungle warfare or to destroy vital food crops of civilian populations. These chemicals are sprayed from the air and have a long-lasting effect on the entire ecosystem, contaminating water and fish as well as plants.
Most major nations have developed probably biological agents to some degree for use in warfare. They include pathogenic micro-organisms such as bacteria, fungi and viruses, or the poisons they produce.
Diseases which could be directed against oncoming armies through the use of pathogenic micro-organisms include anthrax, botulism and plague. Foot-and-mouth disease and stem rust in wheat, for example, could also be used against supporting civilian economies.
Japan used biological weapons against China in the 1930s and 1940s, but large-scale biological warfare has so far not been practised.
The latest twist is the use of these weapons by terrorists. Readers will recall such use of nerve gas in Japan a couple of years ago. More recently, US federal agents arrested rightwing militia members who were carrying a large quantity of anthrax-causing spores.
The potential to wreak havoc with biological weapons is frightening. These are cheap, relatively easy to make and easily hidden. A dangerous amount of infectious agent could fit into an ordinary perfume atomiser. Many of these agents must be deployed into the air as aerosols, which makes their use outdoors fairly unreliable, as they are subject to the vagaries of the wind. However, they can be very effective indoors.
A subway stop makes an ideal target for a terrorist biological weapon attack. The dark suits most biological agents, which are killed by ultraviolet light in sunshine. If a flask of pathogenic bacteria was broken on to the track, the train would create an aerosol as it passed, which would be spread by each train which came along. Thousands of people could inhale a deadly dose, far greater than the number likely to be injured or killed by a bomb.
At least 10 countries are thought to be stockpiling biological weapons. It is generally agreed that anthrax is the greatest threat. It is caused by a bacterium, bacillus anthracis, the spores of which are remarkably hardy and can survive decades even in harsh conditions.
This microbe is very small, half a micron (one millionth of a metre) wide and about five microns long. Untreated, anthrax is fatal 85 per cent of the time. Biological attack often causes no immediate effects and therefore a successful mission means no early remedial measures would be taken.
The incubation period for anthrax is one to six days. A biological attack might not be suspected until large numbers of people showed up in hospital with pneumonia-like symptoms. Death would then occur within 24 to 36 hours. Penicillin is effective but usually must be injected before the first symptoms appear.
An average suspension of anthrax used by a terrorist might contain 10 to the power of 13 spores per kilogram (10 to the power of 13 is 10 multiplied by itself 13 times). These spores could spread through a billion litres of air at a concentration of 10,000 spores per litre.
If you inhale about 6,000 of these spores you have about a 50 per cent chance of developing anthrax. A resting adult inhales about 16 litres of air a minute and would breathe in a potentially lethal dose in a few seconds. The only protection under such conditions is either to avoid breathing or to wear a well-fitting facial mask with a high efficiency filter, capable of trapping particles as small as 0.3 microns.
A treaty banning biological warfare was drawn up by the Geneva Conference in 1971 and approved by the United Nat ions General Assembly. About 80 nations signed the Biological Weapons Convention. The US ratified it in 1974. However, its effectiveness is still questionable.
Terrorists do not feel bound by any treaties or conventions. Terrorist activity is beyond the pale of civilised norms and lawful governments have a strict obligation to use the most effective legal means to protect citizens against acts of terrorism.
William Reville is a senior lecturer in biochemistry at UCC