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Book Summary: Elemental

Author: Tim James

Substory: Poisonous Elements

Humans are a delicate balance of reactions. If we alter one of them we can trigger a chain reaction and the final outcome can be unpredictable.

For example, if you get too much of the element tellurium in your body it causes horrendous breath and elemental silver will turn your skin blue, a condition known as argyria. Even nitroglycerine, which we met as the active ingredient in dynamite, is used to treat angina and nobody’s sure why it works.

One of the few poisons the actions of which we do have a good understanding is cyanide. It works because cyanide molecules bond strongly to iron. If they happen to bond to the iron at the center of a molecule called cytochrome c oxidase, the iron can no longer be used and the whole thing shuts down.

This is bad news because cytochrome c oxidase is the molecule we need to extract energy from food. Switching it off means we essentially starve to death in a matter of minutes rather than weeks.

We also know that some elements, particularly heavy metals, are poisonous because they’re similar to elements your body needs and enzymes can accidentally incorporate them.

Zinc is needed for growth, and the element cadmium has a similar size so if you ingest it the body starts building enzymes with cadmium instead. Cadmium doesn’t have the right orbitals to interact with the chemicals in your body, however, and the result is that you suffer from cadmium poisoning. Your body stops growing.

Lead poisoning occurs because lead is a similar size to calcium, needed to manufacture red blood cells, so if your body absorbs too much lead you can’t make blood. Mercury is even worse because it’s the right size to fit through membranes surrounding your brain. Once it gets inside, it can affect your nervous system, not to mention your thought patterns.

Most people avoid mercury for this very reason but, during the nineteenth century, warm mercury nitrate was used as a key ingredient in preparing hat felt. Sure enough, people in the hat industry soon got a reputation for being a few electrons short of an atom, hence the term “mad as a hatter.”