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The origins and dangers of radon gas

Uranium-238 occurs naturally in lots of rock and soil types

Radon-222 is part of the uranium-238 decay chain, which is one of the three major naturally occurring decay chains we find on Earth.

Try Why Do Astronauts Float by Julian Hamm

It's the radon-222 decay products that are the real problem

Radon-222 is an alpha emitter which further decays into two more alpha emitters, polonium-218 and polonium-214.

Radon is a gas but polonium is a metallic solid.  Most of the radon you breath in is just breathed out again.  But the polonium tends to stick to dust particles and can stay in your lungs.

So it’s the alpha emission from the polonium that is the real health risk.

But it’s the gaseous radon that allows the polonium to become airborne and so have access to your lungs.  We will stick to the convention that it’s the alpha emissions from the radon that are the problem but in fact this isn’t quite right.

back to Lesson 4: Background Radiation