Radiation: the invisible specks and rays that can harm health

How the unstable atoms of certain elements break apart and release high-energy particles and waves that can damage human cells, causing burns or, even years later, serious disease.

- By Kelling Donald

A simplified model of an atom, where the nucleus - containing neutrons and positively charged protons - sits at its centre, surrounded by negatively charged electrons.

(Image: CNX OpenStax/Wikimedia Commons)

The element radium can be found in extremely tiny amounts in the Earth's crust and oceans, and in its pure form it is a soft silvery metal.

To an untrained eye, a small piece of radium may look like a chip off an ordinary grey rock.

But radium can invisibly emit radiation energy and small fragments of itself - that you can't feel, see or smell. And that invisible radiation can hurt you, without you even noticing right away.

What's going on with this silent threat that can stealthily damage your body in ways that can take years to reveal themselves?

As a chemist, I'm interested in what makes different elements safe to handle or hazardous. This dangerous release of radiation is called radioactivity, and even though its source may look unassuming, it can burn you or even give you diseases that don't manifest for years.

Everything you see around you - your skin, rocks, the pages of books - is all made up of different combinations of extremely small particles called atoms.

An atom has a small, dense centre called the nucleus. Negatively charged particles called electrons move around the nucleus. Inside the nucleus, there are two types of particles: positively charged protons and neutral neutrons.