Cesium-137 in your Seafood

Cesium-137 blowing safely out to sea..!!

As the Japanese reactor crisis continues we now find that radioactive byproducts are blowing safely out to sea...? (Depiction at the right from Wikipedia.)

Well, (no pun intended) let's see now...

Reactors (and associated things like pools full of fuel rods) with problems tend to behave in predictable ways.  They emit gases like xenon, tritium and krypton.  They emit radioactive cesium-137, strontium, tellurium and iodine.

Radiation from these things comes in the form of alpha, beta and gamma.

Alpha radiation is basically the nucleus of the helium atom (two protons and two neutrons) with its electrons stripped away.  Beta radiation consists of electrons.  Gamma rays are high frequency radiation produced by sub-atomic particle interaction.

Alpha radiation, since it consists of relatively heavy atomic nuclei, is easily stopped by various everyday materials (clothing, skin, and so on).  Though in large or highly charged doses it poses danger (because the particles are moving very fast) its generally something that you can easily avoid, say by going in doors.  On the other hand, material emitting alpha radiation is dangerous if inhaled or swallowed.

The reason for this is that then the material is inside the body and the alpha particles are directly striking the internal surfaces of your lungs or digestive system.  Because these material may remain static (in place) over a period of time the alpha particles can damage your tissues.

Beta radiation involves electrons striking the body, rather than atomic nuclei.  Electrons are smaller and lighter and therefore, with the same amount of energy, travel faster and can penetrate further into tissues than alpha radiation.  As the electrons penetrate the body they can strike molecules and alter their physical structure.  In particular, beta radiation can alter DNA to cause spontaneous mutations, e.g., cancer.

Shielding from beta radiation is more involved because beta radiation can penetrate about 100 times further than alpha particles, i.e., clothes, buildings and so on are insufficient.

Both alpha and beta radiation cause relatively localized damage, i.e., radiation burns, because they are relatively non-penetrating.

Gamma radiation is the most dangerous of the three.  Gamma radiation is electromagnetic radiation - like light or radio waves - and is highly penetrating and ionizing.  Extensive shielding (like thick lead walls) is required to stop gamma radiation.

Gamma radiation, like beta radiation, can alter the structure of molecules and cells within the body.  Because its penetrating the effect occurs throughout your entire body, i.e., the rays pass through your body altering cells and molecules throughout.  The result is radiation sickness.

The cesium-137 from Fukushima is "blowing harmlessly out to sea"?

I wouldn't be so sure.  First of all cesium-137 has a "half life" of 30 years.  That means if you have one gram of it in 30 years only 1/2 of that gram will still be cesium-137 - the rest will be other things that cesium  decays into.

Cesium-137 also easily dissolves in water.

So as this cesium blows out out to sea it will be integrated into the aquatic life - fish, plants, animals.  It will become embedded in their flesh, cells and tissues.

And for 30 years anything or any one that consumes any of these things will have cesium-137 embedded in them as well because cesium-137 is not altered by digestion.

Once the cesium is so embedded it can emit gamma radiation directly into your body destroying your tissues from the inside.

Cesium-137 in the air is readily breathed in and, once in your lungs, sticks to the mucous membranes, again emitting gamma radiation directly into your internal organs.

For hundreds of years these materials will exist in the aquatic environment - posing a risk to us, our children, our grand children, and great grand children, and so on.

Safe, clean nuclear energy.