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The Epidemiology of Biological Weapons

And the use of masks of all types as a defense for such weapons
Brent Anderson
Dynamic Energy LLC

When considering all biological agents it is important first to understand the language of epidemiologists who study infectious diseases. The fundamental concept that must be understood is that of probability theory as it relates to the interaction of living organisms such as Anthrax, Smallpox, or any of a number of possible pathogens with regard to humans. Assuming mankind as the target and Anthrax as the agent, Anthrax�s relative success with respect to infecting a population requires the use of statistical devices that describe probabilities. We will consider Anthrax and man and try to make some sense of the current panic in our Country and the possible defensive measures that are realistic in light of the current threat.

Beginning with man, the first information we need to have is the probability of infecting a group of people with an aerosol containing anthrax spores. If we assume that everyone will breathe the same amount of air and be equally susceptible, we could try to extrapolate from known data, if there is any, to predict the number of people who would become infected. Unfortunately we have already begun making assumptions that are at best extrapolations, or guesses at worst.

Some have bandied about the number of anthrax spores inhaled and retained in the lungs that are required to cause respiratory anthrax and those numbers vary from 1,000 to 40,000 spores, but what one must ask at this point is how do they know those figures are correct? Who has tested humans with Anthrax to determine these numbers? The answer should be obvious to anyone, and that is no one! These figures again are nothing more than extrapolations (guesses) from animal data or old Soviet intelligence data of questionable repute. If we now consider our hypothetical group of humans, statistically speaking you would expect that there would be individuals for whom even 1,000,000 or more spores would not be sufficient to cause the disease, and at the opposite end of the bell curve, we would expect to find some for whom one spore is enough to infect and kill. As the reader must surely sense at this point, at each turning we make more and more assumptions that may or not be true in the case of an individual. The military solved this dilemma by talking about expected casualties in terms of Lethal dose 50% (LD50), but they always recognized that any figure that they adopted was strictly an extrapolation, or guess.

If we examine Anthrax in the same way we considered mankind, we immediately discover that not all Anthrax bacilli are the same. Some might exude more toxin than others. Some may multiply faster, or be resistant to antibiotics. In every case where we consider any living organism, we find that the description is based upon statistical constructs that may or may not describe individual organisms very well. There has been some effort by some nations to create strains of Anthrax or other pathogens that would be resistant to treatment, or be more infectious. At this time, it would appear that the agent being used in the current Anthrax contaminated letter or package terror campaign is not of military quality, and this is to be expected since the creation of weapon grade Anthrax is an undertaking that only the Soviet Union and the United States were at one time capable. Unfortunately, with the fall of the Soviet Union, some of the scientists involved with the Soviet program are rumored to have accepted employment with the Iraqi Government, thus creating the uncertainty of the moment.

As we consider defensive measures, we find ourselves in the same quagmire of probabilities. If a respirator (gas mask) is used, there are again a number of variables that creep into our consideration. First and foremost, does the mask fit properly? This is extremely important, since breathing with such a mask requires the wearer exert a significant vacuum, and if there is any leakage from the sides, the mask�s protective ability is lessened by a significant amount. Further, even if a mask is worn properly there is still a probability that some Anthrax spores will pass through the filter medium, and as we have previously discussed, this could lead to a fatal infection to those who are especially susceptible. The same can also be said for those who wear pressurized suits with piped in air. There is always a small possibility when dealing with living organisms that a breach will be found in the defensive measures because of the large number of spores involved, and because of unforeseen accidents. The best that can be claimed for such defensive measures is that they will reduce the chances that an individual will contract the disease.

There are other factors that must also be considered the most important being will an individual have a respirator with them when a terrorist attack occurs. In the author�s experience, the number of police officers, military base guards or private citizens that carry the bulky obtrusive gas mask with them at all times is extremely small, certainly far less than 0.1%. Given then that an attack is usually an unforeseen event, most of these individuals will be inoculated before they race back to their car, jeep or barracks and apply their gas mask. It is the author�s opinion that there is only one mask that addresses this critical shortcoming and that is the Air-Aid Emergency Mask. This mask is a very small, inexpensive (Click here to purchase), shirt pocket portable device that allows a person to always have an escape mask at hand, despite the unforeseen. It will significantly reduce the chance of becoming infected, because it is composed of the same filter mediums as a gas mask. The difference is that rather than pulling air through a narrow restriction, as in a gas mask, the wearer breaths through a large surface area thus minimizing leakage from the edges. It does not reduce the probability of infection as much as a gas mask would but then a gas mask would seem to be a rare thing in times of emergency. Factoring in the small probability of an individual actually having a properly fitted gas mask as compared to the probability that they would have an Air Aid Emergency Mask with them yields a combined probability that substantially favors the Air-Aid Emergency Mask as the best emergency option for the average policeman, soldier or private citizen.

Some have expressed a desire for guarantees with regard to defensive measures, but as the reader is by now well aware, there can be no guarantee for any product with regard to preventing infection by a biological agent. The same argument is also true for chemical agents such a Sarin (Agent GB) and again, there can be no guarantees. I suppose that one could increase the chances of not becoming a casualty to such attacks by living in a bomb shelter and never going outside it without a deployed gas mask and full body suit, but this would seem a poor choice for average person. So in the end we should take reasonable precautions and take life as it comes, for indeed there are no guarantees that any individual will live to see the morrow. Life for the average person is always about taking reasonable precautions without degrading the quality of life. The Air Aid Emergency Mask, in combination with rubber gloves, is just such a reasonable precaution and it offers the wearer an unobtrusive, comfortably carried option. It also is comfortable to wear for hours at a time unlike the typical gas mask, which is within a few short minutes irritating to wear at very best.

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