Imagine a super-toxin thousands of times more potent than dioxin and millions of times more deadly than rattlesnake venom. The botulinum neurotoxin, produced by the bacterium Clostridium botulinum, is one of the most poisonous substances known to science. A mere 0.1 grams of this toxin could kill more people than the atomic bombings of Hiroshima and Nagasaki combined. A few grams could wipe out the entire population of Canada.
Not surprisingly, botulinum toxin is widely feared as a biological weapon. The United States Centers for Disease Control and Prevention (CDC) classifies the substance as a Category A bioterrorism agent. Many organizations have developed recommendations to defend against possible attacks. Fortunately, the toxin is unstable and degrades over time, limiting its utility as a biological weapon.
Botulinum toxin is also a concern in the food industry. Foods contaminated with the bacterium can harbor lethal amounts of the toxin, yet smell and taste completely fresh. Canned foods are especially prone because the bacterium thrives in oxygen-free environments. Luckily for us, the toxin is easily destroyed at temperatures over 60°C—just another reason to cook your food.
Despite its extreme potency, botulinum toxin can sometimes be desirable, even beneficial. Every year, millions of people are injected with the toxin, not as victims of terrorism, but as patients of cosmetic and medicinal treatments. The Food and Drug Administration (FDA) have approved Botox—as it is commonly known—for a variety of cosmetic and therapeutic purposes. At minute doses, Botox can reduce facial wrinkles and treat a variety of disorders, including pain, involuntary muscle contractions, and excessive sweating.
Botulinum toxin kills in much the same way it heals—by paralyzing the muscles. At lethal doses, paralysis of the chest muscles responsible for breathing leads to respiratory failure and eventual death. However, at sub-lethal doses, the toxin affects only muscles at the site of injection, allowing it to treat rather than to kill. For example, paralysis of the facial muscles reduces wrinkles, while paralysis of the sweat glands reduces sweating.
