I want to combat some of the misinformation flowing across the net about the unfolding disaster at the Fukushima nuclear plant, because there’s way too much panic, and not enough knowledge.

If you don’t want to read everything below, I’ll summarize: If you live outside of Fukushima, you’re safe.

Here’s ten important facts, in order of “you should know this first”:

1. There is NO danger of a nuclear explosion. The fuel used in nuclear reactors is literally engineered *not* to explode.  In simple terms, it’s too stable, and in more complicated terms, the quantity of enriched uranium and plutonium present in a nuclear reactor is far, far short of the sort of critical mass you would see in a nuclear weapon.

2. The radiation in Fukushima would need to get 2000 times worse before hitting fatal levels. The current radiation level outside of the Fukushima plant is around 1000 µSv, or 0.001 Sv. Mild, usually non-lethal radiation sickness doesn’t set in until around 1-2 Sv, and you aren’t in the danger zone until you hit 6-8 Sv. 

3. This is not to say that there is no danger.  We’re just a very, very, very long way aways from people glowing green and growing extra arms.

4. Your DNA is really, really good at repairing itself, which is why we can take so much radiation before it becomes a problem.

5. The danger of exposure drops off very, very rapidly with distance.

6. The sort of radioactive material you are likely to be exposed to emits alpha-particles. These particles are quite literally stopped by your skin, and won’t cause problems unless they get inside you. The best defense is to keep exposed skin covered, wear a mask, keep your windows closed, and to avoid going outside.

7. The half-life of these particles is measured in days.  The most dangerous stuff (that emits the most radiation) decays faster, which means it’s dangerous for a much shorter period of time.

8. “Radiation Pills” contain potassium iodide. They work because your thyroid really, really loves iodine, and so when you take the pill, they saturate your thyroid with happy, non-radioactive iodine-127.  If you are then exposed to very radioactive iodine-131, your thyroid won’t absorb it, which is good, because you really don’t want your thyroid full of radioactive isotopes of iodine.

9. Potassium iodide offers no other protection against radiation.  It won’t protect you from exposure to anything other than iodine-131, and has toxic side effects if you take a lot of it.

10. There is no such thing as a radiation suit; the suits you see people wearing are just to keep radioactive dust from entering their bodies, and actually offer no protection from the radiation itself.  Any sort of plastic, waterproof garmet that covers the entire body will offer the same level of protection.

So, now you know, and knowing is half the battle.