The intentional use of bacteria, viruses or toxins in warfare is far from new. The poisoning of wells was a common military strategy as early as 600 BC and during World War II, Japan bombed Chinese cities with ceramic shells containing plague infected fleas. In the wake of 9/11, the White House received letters laced with a weaponized strain of anthrax, resulting in 5 deaths.
From a terrorist’s viewpoint, you can see the attraction of biological weaponry. There is a substantial list of biological agents in the bioterrorist’s arsenal, many of which fulfil the criteria for infectivity, toxicity and scalability. Camelpox, closely related to smallpox, is believed to be the preferred disease of Middle East dictators, but diseases such as polio, yellow fever and Ebola could in principle be built completely from scratch, with the genes acquired from biotech companies. As an interesting aside, if you ever wondered how medics were able to develop treatment so quickly to counter recent Ebola outbreaks, it’s because certain experimental drugs had already been developed by bio-defence facilities in case Ebola should ever be weaponized.
Bio-defence is a massive industry and it’s not uncommon for military applications to spill over into commercial application. Project BioShield is an American scheme which has spent billions stockpiling vaccines to meet the threat from anthrax, botulinum toxins, smallpox and other bio-weapons. The UK has similar organizations which try to prepare for possible future terrorist attacks. Is there any way of guessing what these future threats might be?
It’s harder than you might first imagine. The scope of potential diseases which can be used is vast and there are different routes in which the virus, toxin or bacteria might spread. It may be easiest to engineer an already existing human disease and make it more lethal, for example by inserting the gene for botulinum toxin into the flu virus. This way, the method of transmission evolved by the flu virus can be hijacked as a courier service for something much more dangerous. Alternatively, prospective terrorists might infect cattle, crops or even water supplies – all three of these methods have been used with unsettling success in the past. In countries fortunate enough to have stringent quality controls and proper infrastructure, a regulatory feedback system would likely be able to deal with these eventualities. However, the death toll that could be exacted in less developed countries doesn’t bare thinking.
Anthrax is considered one of the more likely candidates for weaponization because of its longevity in the spore form. Anthrax is a disease caused by the bacterium Bacillus anthracis. Spores most commonly enter through cuts in the skin (cutaneous anthrax) and in this form anthrax is rarely deadly if treated. Pulmonary anthrax, in which the spores are inhaled into the lungs, is the rarer and more deadly form which bioterrorists can exploit. Pulmonary spores are between one and five microns: any smaller and the spores just act like a gas and are exhaled; any larger and the spores clump and the disease struggles to establish.
The dispersal of anthrax via a crop-dusting plane or a balloon, is the most likely way of population-wide delivery. Consolation comes from the fact that powdered anthrax is a can of worms to manufacture. This is because the harvested spores make a clumpy peanut butter-like paste that can only be overcome with a fiddly procedure which involves coating the spores in silica or aluminium oxide. Of course, anthrax isn’t the only threat, there are plenty of other bioweapons knocking about.
Apart from stockpiling vaccines and improving early detection procedures, one of the ways governments try to combat the threat of bioterrorism is by introducing new policies into scientific research to limit what they dub “dual-sided” investigation. This essentially involves blocking either the publication or conduction of research which could be subverted for use by extremists.
Should we be worried about bio-terrorism? Certainly it is very possible to cause devastation using or tinkering with the products of nature, but for that devastation to be large scale requires a high level of organisation and skill. It’s hard not to be at least a little worried, given not only humanity’s desire for scientific advancement but also our capacity for war.