MXPX VX: punks and their weapons of mass destruction

“It is easy to scare people if they don’t know enough to judge how big a risk something is to them,” said David Richardson, professor of chemistry. We’ve all heard the term “weapons of mass destruction” hundreds of times in the past few months, but most people do not have a clear sense of what the term means or the potential threat these weapons pose.

There are three main kinds of weapons of mass destruction: biological, chemical and nuclear. Biological weapons either infect people, causing them to act as vectors for a disease, or they wipe out crops, depleting the food supply. Chemical weapons disable or kill people. Nuclear weapons destroy everything in their path and send harmful radiation throughout the surrounding area.

Anthrax and smallpox are the two biological weapons that have been most prominent in media coverage. (Anthrax is a disease caused by bacteria that spread quickly because they can enter a spore form that travels easily and is resistant to environmental extremes.) Smallpox is an extremely infectious virus and the only disease that the World Heath Organization has ever declared eradicated. Their similarities lie in their great virulence: both spread rapidly and are often fatal.

(The bacteria Bacillus anthracis has a lifespan that includes a spore phase. In this form, the bacteria can survive extreme heat or cold, radiation, pressure and chemical erosion.) Normally, they live in the soil as spores until they are ingested by an animal host, where the temperature signals them to come out of spore phase and germinate. Within their animal host, they multiply quickly and cause damage by greatly hurting the immune system and creating a buildup of lethal toxins that swiftly kill surrounding cells.

Anthrax bacteria normally infect herbivores, but people are vulnerable through contact with meat, open wounds or breathing airborne spores. Amy Gehring, assistant professor of chemistry, pointed out that even when rapid medical treatment manages to kill the bacteria within the body, it is often too late because they have already created enough toxins to kill the host. Anthrax spores are aerosolable and extremely difficult to kill, which is what makes them so threatening.

Smallpox was declared officially eradicated in the latter half of the twentieth century, but lately there have been concerns that small surviving amounts of the virus would be used as weapons of mass destruction. This has opened the question of whether or not to vaccinate, and if so, how best to protect the public. Some researchers think it advisable to vaccinate only a core of health-care workers and the like, while others think that mass vaccination is the most effective protection.

Still others advocate an intermediate method that vaccinates the core and the “ring” of people who come in contact with that core. Epidemiologists must also take into account immuno-compromised individuals, such as those with AIDS or those undergoing chemotherapy, who cannot be vaccinated.

Lois Banta, visiting assistant professor of biology, said that not all biological weapons target humans. She personally is more concerned about weapons carrying a fungal disease that could destroy the grain supply. A weapon that creates food shortages is threatening indeed, and while we can vaccinate against smallpox, we cannot immunize crops to the various diseases that could infect them.

Chemical weapons were first developed for use on battlefields at the beginning of the twentieth century, but now the fear that they may be used in cities or other areas of high population density. Chemical weapons have a limited range in that they can kill or injure everyone in a building, but not every person in a city. They can, however, be dispensed before people are concentrated in an area and render that space toxic for days. They are divided into four main categories.

Irritating and choking agents temporarily incapacitate their victims. They are dispersed as gases, inhaled and absorbed through the lungs. They cause mucous membranes to create excessive fluid, causing tearing or, more seriously, fluid build-up in the lungs, which can lead to choking. Most are not fatal; the best way to avoid injury is to get away from the area. Tear gas and riot gases fall in this category.

Blister agents are also not fatal, but they cause severe burning and blistering of the skin, windpipe and lungs. They are either inhaled or absorbed through the skin. Immediate medical treatment is required because the blistered mucous membranes are very sensitive and if the blisters burst, infections set in.

Nerve agents and blood agents are both fatal. Blood agents are dispersed as a gas and absorbed through the lungs, where they enter the bloodstream and render the body’s muscles incapable of using oxygen and producing energy. Muscles become paralyzed and most people die from not being able to breathe. Even in cases where breathing still occurs, a general muscular paralysis attacks the heart and causes it to stop beating.

Nerve agents are either airborne gases or liquids. Lethal doses can cause death in five minutes. Nerve agents attack acetylcholinesterase, an enzyme that normally acts to break down neurotransmitters so that they can be recycled in new nerve impulses. When the system of sending nerve impulses fails, muscle control of both voluntary and involuntary muscles is lost. The heart and lungs stop working and death is swift. Soman, tabun, sarin and VX are all examples of nerve agents.

“Nuclear weapons, quite simply, liberate a tremendous amount of energy,” said Daniel Aalberts, assistant professor of physics. “Conventional bombs liberate energy by using chemical reactions, but nuclear bombs do so by splitting the atoms of either uranium or plutonium.”

Interestingly, as Aalberts pointed out, each split atom produces enough energy to move a speck of dust. But because there is a critical mass of millions upon millions of atoms, a nuclear bomb creates a very large dust displacement.

Uranium and plutonium are massive atoms, so both have many protons tightly packed in the nucleus. Like charges repel each other with coulombic force, so all of the protons are repelled from each other and the only thing preventing them from flying out of the nucleus is the strong nuclear force, which can attract like charges, but only over an extremely tiny distance.

Also in the nucleus are neutrons, which have no charge. Just one extra neutron flying into the nucleus can upset the delicate balance of forces and split the atom into two smaller chunks and two or three free neutrons. These neutrons can then fly into other nuclei and split them in the same manner, and thus there is a cascade of reactions in a nuclear explosion as each atom that splits has the power to split two or three of its neighbors.

The basic principle of a nuclear bomb is very simple, but creating the apparatus to initiate the explosion properly is extremely difficult. This difficulty, paired with the cost of obtaining the correct unstable isotopes of uranium and plutonium, is what prevents a reality where every country with the financial wherewithal has a nuclear arsenal.

“Any country with enough time and money can do it in theory,” Aalberts said.

Each type of weapon has advantages and drawbacks. “Chemical weapons break down over time. They don’t multiply, like biological weapons,” Richardson said. “Nuclear weapons are harder to transport and conceal than biological ones.” Yet nuclear and chemical weapons can cause instant death, unlike the diseases spread by biological weapons.