In general when people hear about radiation, they may instantly think about the atomic bomb and all its negative associations. However, this is not necessaraly the case. Radioactive elements have some important uses in fields such as medicine or science, but they can also be the cause of dangerous problems if they are not handled properly.

Radiation, even in small doses, can cause cancer in humans and other living things (this is why hospitals are so careful about X-Rays). Fast moving photons (gamma rays), electrons (beta rays), and helium nuclei (alpha particles) can crash into other molecules and change their structure. If this happens to a DNA molecule, it can damage the genetic information, and sometimes turn a cell cancerous.

Coming into contact with radioactive elements increases the risk of cancer, however, ingesting it increase it substantially more as it stay within the body.

Particularly nasty radioactive elements are radon and radioactive iodine. Radon is a chemically inert gas with a short half-life (and therefore decays rapidly, emitting radiation faster than other elements). It can be found naturally both in rocks and soil. It might be diffuse through basement walls and into people’s homes and increases the rate of lung cancer when people breathe it in. In areas where radon is common, it is recommended to ventilate the basements and have them checked regularly.

Radioactive iodine is also readily absorbed by the body and becomes incorporated in bones, and is therefore difficult to eliminate altogether from the body. The radiation it emits can cause bone cancer over long periods of time.

The radium on watch dials used to be incorporated in paint. Workers used to paint the watch dials by hand, and some would even lick their paintbrushes to make a sharper tip. They ingested radon paint, and many became ill with cancer.

Naturally occurring uranium also was used to make bright yellow paint, but this too has been stopped.

Plutonium, apart from being radioactive, also happens to be just plain poisonous. Human bodies do not deal well with heavy metals such as lead, mercury, and arsenic spring to mind as things not particularly wise to ingest because of their poisonous properties. Plutonium may well be the most poisonous of the lot.

The Earth is a big place, and there are a lot of radioactive elements of varying degrees of radioactivity distributed throughout it. To eliminate all the radioactive materials is impossible, we can’t just get rid of them, or make them somehow stop being radioactive. Also Uranium and thorium ores in the ground are only mildly radioactive.

However, a more pressing concern is what to do with man-made nuclear waste generated as a by-product of weapons manufacturing and nuclear power plant waste. Currently the best ideas are just to put the wastes somewhere where people won’t go, and away from water that people will end up drinking, while waiting for the materials to decay for tens or even hundreds of thousands of years. It’s a tough job trying to predict how a geological formation will behave in that long a time. We might safely store it in a mountain today, but one does not know if the mountain is going to be there in tens of thousands years from now.