Man-Made Radiation in the Air: Primer

This post is going to be the first of a three-part series on "atmospheric dispersion of radionuclides". The intention is to give some basic information on the topic that would otherwise clutter the other two topics, weapon fallout and power plant release.

Why do we care?

Man-made radiation releases to the atmosphere are a top priority for many nuclear regulatory and research organizations around the world. [1] The primary reason being that the air provides both the fastest and widest-reaching medium for radioactive particles and their radiation to spread to and around an area. Though radiation can and will travel through water, soil, and underground, none of it beats the speed or area coverage of radiation in the air. Plus, humans have a tendency to breathe the atmosphere; as we discussed with radon, radioactive material in your lungs is something you should avoid whenever possible.

The ability to avoid it is another reason why it's so important--or more accurately, the lack of an ability to avoid it. Depending on the source event, radiation in the atmosphere can travel very quickly over a very large area. If that area happens to include where you live, unless you evacuated a while ago chances are you're going to be exposed to something.

What's in the air?

That "something" depends on the source event. Many radioactive nuclear byproducts exist naturally in a gaseous state. We've already discussed radon, but alongside it can be krypton, xenon, radioactive isotopes of oxygen or nitrogen, and a few others, none of which are going to be very good for you if you breathe them in. Depending on the energy behind the release (e.g. a bomb versus a reactor venting, which we'll get into in the other parts of this series) there may be heavy elements flying through the atmosphere as well. These elements, which can be decaying with all kinds of nasty radiation from high-energy gammas that can do damage no matter where they hit you, to alpha particles that can really hurt the interior of your lungs when you inhale them. They also tend to be part of long decay chains, which means they and their "daughter" elements can still be highly radioactive even after a large amount of time has passed (we'll discuss this further in the subsequent posts).

To be continued

I know the stated idea of this blog is to try and assuage some fears about nuclear, but it sure sounds like I've done some fear mongering here. I just wanted to build a bit of a teaser for the more in-depth posts to come, on the atmospheric radiation from nuclear weapons and non-weapons. I will say that thankfully, the number of man-made events resulting in the release of radionuclides to the atmosphere are quite few; unfortunately, most of them have been very serious.

Up next will be a discussion of nuclear fallout from weapons, and its lasting effects.

[1] https://rem.jrc.ec.europa.eu/RemWeb/activities/AtmosphericDispersion.aspx