On being naturally radioactive....

There is a perception that radioactivity and radiation are very very bad things. This is not entirely correct. Not all radiation is a bad thing.

For starters, not all forms of radiation involve radioactivity. Radiation is simply the emission of energy from a source. The lamp I am sitting next to right now is radiating visible light and infrared (IR) energy (also known as heat). My oven radiates IR. The TV radiates visible light. The microwave oven I own uses microwaves to heat things. The process of sending those microwaves through my cup of hot chocolate is radiation. None of these processes I have named involves radioactivity.

Radiation can be electromagnetic (wave) or particulate. Forms of electromagnetic radiation include visible light, ultraviolet light, infrared, radio waves and gamma rays. Particulate radiation emissions include alpha and beta particles, plus neutrons. An alpha particle is a helium nucleus--2 protons and 2 neutrons. A beta particle is an electron or positron.

Some radiation emissions have sufficient energy to ionize atoms (kick an electron out of the atom). This is known as ionizing radiation. Other emissions are not energetic enough to accomplish evicting an electron and is deemed non-ionizing radiation. Non-ionizing radiation can still cause lots of problems. If I lay my hand on the burner of my stove after it's turned on, I will suffer thermal burns even though no ionization occurred. Radio waves, microwaves, infrared, ultraviolet and visible light are all non-ionizing.

Ionizing radiation, the kind usually associated with particle radiation and some electromagnetic radiation (gamma and X-rays), has the energy to remove an electron from an atom. Sources of ionizing radiation include radioactive decay, nuclear fusion and fission and the sun. Ionizing radiation can cause DNA damage, so rapidly dividing cells are particularly susceptible to damage. Because it can induce DNA mutations, ionizing radiation can cause various forms of cancer, especially during chronic exposure. Acute exposure of high levels of ionizing radiation usually results in tissue death.

So, how can a person be naturally radioactive? There are natural sources of radiation in the environment. I have seen estimates of annual average radiation exposure in the US is 360 millirem (mrem). The vast majority of this is from natural sources and the remainder is almost entirely from medical sources (X-ray imaging and CT scans). Radon gas, a product of the natural decay of radium, is another natural source of radiation to which people can be exposed. Radon levels are elevated in areas where uranium deposits are found in the underlying geological structures. One such area is found in the eastern third of Tennessee, under Oak Ridge National Laboratory. In addition to radon, there are numerous common elements, such as carbon, phosphorus and potassium which have radioactive isotopes. The radioactive forms of these elements make up a very tiny proportion of the total amount of that element. But it's enough to make you and me and everybody else on the planet naturally radioactive. And now you know.

Knitting progress:
I have two hats made for The Dulaan Project. I haven't worked on a hat in two days. Perhaps tomorrow I'll start a new one. I did spin for about 90 minutes last night and for another hour today. I'm working through my stash of merino roving. I'd like to produce a 3-ply worsted weight yarn as a final product and then make myself a sweater.

I spent several hours today working on a sock while riding in a car for 5 hours. I did discover that I managed to break a single size 2 Bryspun double point at some time in the past several weeks. Fortunately I purchased a set some time ago that accidentally had 6(!) needles in it, so I'm even with where I should be. I think the blue sock is now 1/2 way down the foot. This is the second attempt at socks with this yarn. The first pair was knit in a basketweave pattern and the gauge varied widely between the two socks. I finally just frogged them and started over.

The stash room has been quietly telling me that it needs to be organized and catalogued. I did start an Access database some time ago for that very purpose. I never did finish it though because most of my stash was actually in a storage space, not where I could get at it easily. Perhaps that will be one of my winter projects. And then I can plan out what knitting, spinning and weaving projects I would like to accomplish.


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