|Saturday 20 October, 2001
Only a few weeks ago, most of the world knew little about anthrax beyond the fact that it could be a lethal infection to have.
Now, following a series of incidents, we not only know what it is and what it can do but we're starting to ask questions about what type, or grade, it is. BBC Science reports.
Weapons grade anthrax
On 15th October 2001, a letter containing anthrax was opened in the office of US Senate Majority Leader Tom Daschle.
Following the incident, that exposed over 30 people to spores, Senator Daschle was quick to suggest the Capitol Hill anthrax was no ordinary strain. He said:
‘We were told that it was a very strong form of anthrax - a very potent form of anthrax - that clearly was produced by someone who knew what he or she was doing.’
Exactly what the phrase "a very strong form of anthrax" meant wasn't clear; but pretty soon reporters were using the term "weapons-grade" - even though Senator Daschle later said this wasn't what he'd meant. But in any case, what does the phrase "weapons-grade" really mean?
One potential implication concerns the size of the spores. Dr Randi Hyer from the Department of Communicable Disease Surveillance and Response Unit at the World Health Organisation says they need to be very small if they're to travel along the human airways to the alveoli, the tiny air pockets in the lung:
‘The size of particle to reach the distant terminal alveoli have to be a certain size. If they're too big they'll get caught before they get to the end of the road; if they're too small, they'll simply be breathed right out again. So the particle size has to be critical; and it's usually felt to be between one micron and five micron.’
|How big is a micron? || |
|A micron = |
So the term "weapons-grade" could mean spores which had been intentionally made this size - something which according to Michael Powers of the Chemical and Biological Arms Control Institute in Washington DC, requires substantial skill and resources. He explains:
‘It's one thing to obtain a seed culture of the anthrax organism and then to mass produce it. It's a completely higher level, or an extremely higher level of technology to go through the process of freeze-drying that agent and then milling it to produce the fine, dry power which seems to have been released in Senator Daschle's office.’
Anthrax could also be described as weapons-grade if the particular strain of the bacterium is particularly infectious, or difficult to deal with - its genes making it especially virulent, or resistant to antibiotics.
But does it really matter what grade the anthrax is? In medical terms, Dr Hyer thinks not:
|‘There is I think a lot of fear and hysteria that is being worked up by the unknown. I think we need to keep in mind that there have only been a few actual cases; anthrax is also a treatable disease.’ |
Whichever form it comes in, prompt treatment with antibiotics will almost certainly be successful.
To find the real implications of the grading issue, we have to turn to the political sphere.
Ever since 11th September, there have been signals from President Bush and others in his administration, that they suspect Iraq of involvement in attacks on the United States.
Addressing the nation, President Bush recently stated:
‘There's no question that the leader of Iraq is an evil man. After all, he gassed his own people. And we know he's been working on weapons of mass destruction.’
These weapons include anthrax. If the envelope in Senator Daschle's office did contain a highly-sophisticated form of spore, it could mean that a nation's resources, rather than those of a terrorist group, have produced it.
Michael Powers believes the anthrax is high-grade, implying state involvement. He comments:
‘I would suggest that it would be fairly unlikely that this form of anthrax could be produced by a terrorist organisation or a non-state actor.’
‘I believe this particular type of anthrax was produced most probably by a state-level bio-weapons programme. What state, and who might have produced it, it's difficult to say with any certainty at this point.’
Genetic analysis of the bacteria could potentially lead back to the state concerned; several laboratories are currently looking for clues.
Closer to home
However, not everyone agrees that the Capitol Hill anthrax was special. Scott Ritter was a United Nations biological weapons inspector in Iraq, he believes the source of the outbreak may be much closer to home. He explains:
‘I believe that this anthrax comes from the United States. I believe this is anthrax that had been produced in a laboratory, probably by some organisation that is developing vaccines - they lost control of it, and whoever is carrying out these attacks has taken it and used it.
|‘Remember, this isn't weapons-grade anthrax. This could be nothing to do with Osama bin Laden at all - rather it could be the work of some home-grown, right-wing fanatics.’ |
The FBI, for its part, says it has not yet reached a conclusion - its analysis continues. Only when it releases definitive data will we know if the finger of suspicion points at a power distant from the United States or whether the truth is, less comfortably, nearer than we would like to think.
| Nerve gas
|Iraq is believed to have produced mustard gases and a deadly nerve gas called VX.
In August 1988, Iraqi forces were reported to have used both chemical and gas munitions against Kurdish civilians in Iraqi Kurdistan.