More Radiation Stuff - Hot Particles

I touched on hot particles previously. They are still somewhat in the news with the west coast of the US testing for up to 5 hot particles per day estimated per person.

A hot particle is a microscopic bit of a radioactive substance. The size of the particle can range from a few nanometers (a billionth of a meter) to a few micrometers (millionths of a meter). An atom of Cesium-137 has a diameter of about 0.4 nanometers. So a molecule of Cesium-137 oxide or whatever it happens to react with would be a little larger. For the sake of simplicity, let's say 1 nanometer since the particle may contain a little of something else.

Then a hot particle of Cesium-137 will contain anywhere from a few hundred Cesium-137 atoms to a few hundred thousand. For simplicity, let's say 100,000.

With a half life of 30 years, there would be 50,000 decays in 30 years, around 1700 decays per year, about 5 decays per day, per hot particle. With the bad luck of inhaling all 5 hot particles per day, that would be about 1 decay per hour. So if your bad luck continues, in sixty days you would add 60 decays per hour or 1/60 Becquerel to your radiation exposure. Becquerel is defined as decays per second.

Cesium-137 is convenient since it makes up the bulk of the radiation fallout. If the Hot Particle was Plutonium-239 with a half life of 24000 years, the decays would be 30/24,000 times 1 Becquerel. Roughly of course, since the diameters are a little different, but not much.

Based on food radiation limits, about 500 Becquerel per kilogram is safe, so to add the health impact of supposedly safe food day of meals, every sixty days you add one Becquerel so in 82 years you have accumulated 500 Becquerels of radiation from hot particles if you are unlucky enough to inhale all five hot particles per day of a Cesium-137 compound for 82 years.

Update: I used CPM instead of CPS, but you should still get the idea.

Wow! That sounds pretty dangerous to me! So if you plan on living to be 240, I would be scared shitless.

During the atmospheric nuclear testing age, there were a lot of hot particles. Chernobyl produced lots of hot particles. How much health impact have those hot particles had on cancer rates? Not a whole hellava lot since most folks don't live past 80 years. Do you think maybe that the hot particle press releases might be a little sensationalized?