Radiation: Definitions

Disclaimer: I’m not a scientist. My husband (read his thoughts here) has studied nuclear engineering, and I’ve done some research. We wanted to assess the possible risks of the low intensity radiation we encounter every day and know what precautions we should or shouldn’t take.
I want to blog about this because of how much hype is out there about it. I don’t want to become a food/health blogger, though that is something I enjoy reading and researching. Instead, go to great places like 100 Days of Real Food, Wellness Mama, Keeper of the Home, Thank Your Body, and Mommypotamus.  I’m not 100% on board with everything they do or recommend, but there’s so much good stuff on all of those sites. Read and research for yourself!
To view our whole series on Radiation, click here.

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What does radiation make you think of?
Most connect radiation with events like Hiroshima and Chernobyl, where large doses of radiation had deadly effects, both short and long-term.
However, radiation from nuclear bombs and plants isn’t the only source of radiation, and for most of us is never going to be a concern. But that doesn’t mean we’ll never come into contact with radiation, as our bodies absorb radiation from both natural and manmade sources every day.

The radiation we encounter on a daily basis is from the ground, our walls, the sun, mobile phones, and even the bodies of other people. The good news is that while it affects our bodies according to the same laws as more intense radiation, there is so much less of it that it has no measurable effect on our bodies. Even though we may not be able to completely avoid this kind of radiation, there are things we can do to minimize exposure and bodily damage.

Before we go on, there are some terms I want to define to make sure we’re all on the same page. In the previous article, we defined the different types of particles and their damage potential. The following terms can be categorized under a number of particles and have to do more with the energy of the radiation than the kind of radiation.

You’ve probably heard a lot about extremely low frequency radiation, also termed “ELF.” Just like it sounds, an ELF particle, whether gamma, alpha, or anything else, has a lower frequency than other radiation. Thus, it will do no known damage to a human cell it travels through; however, it’s the long-term effects of ELF that are under question. What are examples of ELF?

“Microwave ovens, global positioning systems, cellular telephones, television  stations, FM and AM radio, baby monitors, cordless phones, garage-door openers, and ham radios… Other forms include the earth’s magnetic field, as well as magnetic field exposure from proximity to transmission lines, household wiring and electric appliances.These are defined as extremely low-frequency (ELF) waves.”[1]

Another buzzword often heard with ELF is EMF, which is shorthand for electromagnetic field. An electromagnetic field is a physical field produced by electrically charged objects. The concern about EMFs often surrounds things like power lines and electrical devices, presuming that coming into contact with the electromagnetic field of cell phones, wifi, etc. might have negative effects on our health.

We also often categorize radiation as being ionizing or non-ionizing.

Non-ionizing radiation does not have the energy to remove an electron from an atom or molecule, but can have enough energy to excite electrons.[2] Higher energies in this category (the optical range) can cause cellular damage.[3] Lower energies in this category can cause “thermal-ionization”, which we know as burns. [4] Still lower energies in this category, which can induce low electrical currents, have no known effect on cells, but are the the subject of debate and research in medical circles. The examples of ELF listed above are non-ionizing.

Ionizing radiation occurs when the energy of particles and waves is high enough to upset electrons in our cells, giving an atom a positive charge and creating an ion, hence the term “ionizing.” A particle’s ability to ionize depends on the energy of individual particles or waves, rather than their number, and higher frequencies usually have higher energy. We are exposed to natural, ionizing radiation every day from the ground, sun, and other people, referred to as background radiation. The damage incurred from ionizing radiation depends on the dose of radiation received, and because our daily exposure to ionizing radiation is so low, our bodies have time to heal and thus it is not cause for concern (high radon levels, however, can be cause for concern, but that’s another discussion). For a breakdown of how much background radiation we receive, view this document.

A good graph to summarize can be found here.

Now that we’ve defined our terms, we’ll discuss how different forms of radiation affect us in the next installment.

 

[1] http://www.nuclearsafety.gc.ca/eng/resources/radiation/introduction-to-radiation/types-and-sources-of-radiation.cfm

[2] http://web.squ.edu.om/med-Lib/MED_CD/E_CDs/anesthesia/site/content/v06/060155r00.HTM

[3] On the upper end of the non-ionizing spectrum are some forms of light that can cause photochemical reactions, which you can read more about here. Since it only has to do with light, I’ve left it out of our main discussion.

[4] Read more about non-ionizing radiation here.

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