Radiation’s Effects And Materials To Mitigate Them

Was advised it might be a good idea to repost some of my nuke related posts, so here you go.

Re-Post from MDSA


While in conversation with a friend the other night, he mentioned the two previous posts that were published on this blog, and asked if more topics could be discussed. I advised him that there were more in the works, and it was just time constraints that limited their release. Today we will talk about what types of radiation are of concern in a nuclear war context, what kind of a threat they are and for how long, and ways to mitigate those effects. Throughout all this information we will put out about radiation protection, the three basic things to keep in mind that you can use to protect yourself from radiation are Distance, Time, and Shielding.


Generally speaking, there are three types of radiation that we are concerned about. Alpha, Beta, and Gamma. The Alpha Radiation/particle is the least dangerous realistically, but it is still a concern. The effects it has can be mitigated by 1 inch of air, a layer of common clothing, and even your skin to a degree. The place where Alpha Radiation can cause you damage is if you ingest it, whether through inhaling or swallowing it. It can cause serious issues with internal organs it comes into contact with. A tightly sealed bandanna, commercial dust respirator or gas mask will inhibit the inhalation part, and cleaning your food off will generally stop the swallowing it part. Keep in mind though, the Alpha particle is 20 times more damaging to human tissue (in contact) than an equal amount of Gamma radiation/rays.

Beta Radiation is more of a concern, but it is usually stopped by 10 inches of air, or several layers of clothing. As with the Alpha particles, Beta’s are also a concern if ingested, and the commercial respirator or gas mask still applies for that concern. Although regular clothing in layers will usually defeat Beta particles, I suggests using a heavy commercial rain suit (pants and hooded jacket will work, but the “overall” type pants with a jacket or a trench coat type jacket with regular pants will work better for the overlap these combos provide), heavy rubber over boots, and gauntlet style rubber gloves (all this was talked about in this post) will help with a speedy decontamination when you arrive back at your home/retreat. You simply get brushed off then sprayed off in a designated decontamination area with a water hose.

Gamma Radiation is the big killer in a nuclear fallout context. Unhindered by a barrier, Gama particles have a range of a 1/2 mile. The way to defeat or mitigate the effects of Gamma radiation is to not be anywhere near it, or to use different types of material to shield against it. The radiation output measurement is called Gray (Gy) or Rad (R) and is measure by the hour.



The “Rad” term is an older one (old US system), and 1 Gray(Gy) equals 100 Rad (R). The term REM stands for “Roentgen Equivalent Man” is generally equal to the same amount as a RAD (1 Rad= 1 REM). The REM is the older US system’s nomenclature for dose received and 100 REM’s  are equal to 1 Sievert (Sv). Both REM and Sievert are a measurement of the dose received by the individual. 1 Sievert equals 100 REM in dose, 1 Gray equals 100 Rads in radiation measurements per hour.   If you are told the radiation level is 1,000R (10 Gy), that means it is 1,000 Rads (10 Gy) in an hour. If you are told the dose received is 1,000R (10 Sv), it means the person received 1,000 REM (10 Sv), and if that person was exposed to that dose for 3 hours, it would not be 1,000 REM (10 Sv), but 3,000 REM (30 Sv).


Here’s another chart in my notes that will give you an idea of what happens after you are exposed to a given amount of radiation in a given time period.

Doses are listed as REM.

  • 0-70=  Dose period/6-12 hours. No effects to slight incidents of headache, nausea, vomiting. Up to 5%. No medical care required.
  • 70-150= Dose period/2-20 hours. Same as above, from 5-30% effected. Some medical care might be required.
  • 150-300= Dose period/2hrs-2 days. 20-70% percent same as above. Fatigue and weakness in 25-60% of personnel. 5% deaths at low end, 10% at high end.
  • 300-530= Dose period/2hrs-3 days. 50-90% as above. Fatigue and weakness in 50-90%. At low end 10% deaths, at high end 50% deaths
  • 530-830= Dose period/2hrs- 2 days, 80-100% of personnel with moderate to severe nausea and vomiting. 2hrs- 6 weeks, moderate to severe fatigue and weakness in 90-100%. 50% dead in 6 weeks at low end, 99% dead in 3 weeks at high end
  • 830-3000=Dose period/30mins to 2 days, severe nausea, vomiting, fatigue, weakness, dizziness, disorientation, and moderate to severe fluid imbalance and headache. 100% death in 5 days to 3 weeks
  • 3000-8000= Dose period/30mins to 5 days, 100% experience severe nausea, vomiting, fatigue, weakness, dizziness, disorientation, fluid imbalance, and headache. 100% death in 2-3 days
  • Greater than 8000= Dose period/30mins to 1 day, severe and prolonged nausea, vomiting, fatigue, weakness, dizziness, disorientation, fluid imbalance and headache. 100% death in 1 day

Understanding The Half Life of gamma radiation.

There is a basic rule that applies to the effectiveness of radiation, this is called the “Rule of Sevens”. “Half-Life” is the term used to measure the amount of time required for the radioactivity being generated to be cut in half. When measuring Gamma radiation, we use the “Rule of Seven”. In a nut shell this means that for any given amount of radiation, a time span of seven will reduce that radiation to 10% of the quantity previously measured (it will be reduced 90%).

If we start with an example of 2000R in your area one hour after a detonation (H+1), within 7 hours, the radiation level will be reduced to 200R. After 49 hours (approx 2 days), the radiation is reduced to 20R, and after 14 days (two weeks), it will be reduced to 2R. Finally after 98 days ( approx 3 months) it is at 2/10R. Note that the chart above does not measure below a dose rate of 1Gy/1Sv (100 R/100REM). Although there would be trouble spots where fallout would have collected, for the most part, you are relatively safe to come out of the shelter after two weeks in all but the worst hit areas. If you are in those areas, I think you probably would have had a more immediate concern from the initial blast damage, than the radiation.

Blocking Radiation

So now we’re all depressed because we realize what radiation will do to our bodies, let’s talk about how we’re gonna stop it. We’ve already talked about how to block the radioactive Alpha and Beta particles from harming us internally and externally with protective apparel, but one other thing to mention in this regard is potassium iodide (KI) tablets. These are to be taken 48 hours prior to a possible exposure to Alpha and Beta particles due to ingestion or inhalation (they don’t help with external radiation exposure).


It’s good to have them on hand in case you won’t have the ability to block the inhalation or ingestion of Alpha or Beta particles with some type of respirator, but KI does have numerous side effects that are possible after being taken. Also, KI is not recommended for people over the age of 40, due to side effects affecting the thyroid that are possible.


OK, so now we are going to shelter in place, and we need to build or add to a shelter, whether it is a shelter within a building, or making the whole building into a shelter. What are some common materials that are available to us for use in our shelter.

We will talk about a number of readily available materials and what radiation shielding capabilities they have. First up is air.

AIR– Distance is your friend when it comes to radiation. To cut the output of radiation in half, you need 200 feet of air/space. This 200 feet of distance will halve whatever Rad or Gray count is emanating from the source of the radiation. Using an uncontaminated parking garage basement that you decide to build a shelter in as an example. If you have 200 feet of air between you and the outside, discounting any other material (steel, concrete, etc) the radiation level is cut in half with that 200 feet of distance. Different types of architecture (high rises) will assist with this.

DIRT– It requires 3.3 inches of dirt to halve the amount of radiation that is put out from a source outside the shelter. If you have an outside radioactive source, 12 inches of dirt will reduce the radiation to 1/10th of the original output, 23″ to 1/100th, and 33″ to 1/1,000th of the outside radiation output.

WOOD– Wood will reduce the effects of outside radiation to 1/10th with 35″, 1/100th with 58″. and 1/1,000th with 88″. The halving thickness is 8.8″.

STEEL– Steel’s radiation reduction is as follows: 1/10th is 2.3″, 1/100th is 5″, and 1/1,000th is 7″. The halving thickness is .7″.

CONCRETE– 10 inches of concrete will block 1/10th of the outside radiation, 15 inches blocks 1/100th, and 23 inches blocks 1/1,000th. The halving thickness is 2.2″.

PAPER– the protection books and magazines provide equals 1/10th with 28 inches, 1/100th with 54 inches, and 1/1,000th with 77 inches. The halving thickness is 7.7″

WATER– Something like a waterbed in the room above might be factored into your protection. Water provides 1/10th the exposure with 19 inches, 1/100th the exposure with 30 inches, and 1/1,000th with 48 inches. The halving thickness is 4.8″.

In case you didn’t notice, the denser and heavier a substance is for a given size (example 1 cubic foot) the better the protection and shielding from radiation.

In the next nuke series post, we’ll talk about using some of the materials listed above to build shelters out of your home, within your home, and in a building you might get caught in or in the open after a blast.




10 thoughts on “Radiation’s Effects And Materials To Mitigate Them

  1. So I have playing around with an idea. I want to make an air filter for the home to make the interior a positive pressure environment. My thought is that it would help keep out particles/dust during an event. I want to keep it simple, think box fan with filters behind it, in say a window or hole cut into the exterior wall. Obviously it would be a drain on the fan and might need to be replaced often. Any ideas on filter materials? I’m think multiple layers, cheesecloth, furnace filters, maybe a layer of cotton. Is this a stupid idea? Thanks JC

    • Maybe start with fine metal screen on the exterior surface for durability, then some type of cloth that is more durable than the furnace filter, then a furnace filter as the fine particulate remover.

    • Have you ever used a Rainbow vacuum cleaner or a water bong? Bubbling air through water does a good job of trapping particles.

      • Yes I have. I have also considered the water factor. Swamp coolers are big in my area, easy to make and work on too.

    • Sir: The typical box fan has poor air moving characteristics when trying to move restricted [filtered] air.
      A better option might be a squirrel cage fan assembly similar to a furnace or a small combustion air application. Note the curvature on the blades. Flatter blades of course, move less volume and versey vicey. However, more air moved = more amp draw. If no power, then @ squirrel cage assemblies could be coupled up for days with some wind. One blower, the larger, as the wind driven source of rotation and the smaller fan as the driven supplier of filtered air. Still dependent on fan location, air speed and funneled air velocity into the wind collection plenum. Not so good on calm days….. hence solar. soapweed

      • Thanks for the feedback soapweed. I will be looking at amp draw on a few different units. I have gennies, but don’t want to use them 24/7 so a little solar or wind set up, we almost always have a breeze, to run it would be the best way I think. Any fan could be set up to run by a windmill or even by hand or foot crank with some effort. I suppose that just a filter set up without a fan would be better than nothing to keep clean air moving into the house.

  2. Pingback: Repost: MDT And Things Nuclear | Western Rifle Shooters Association

  3. Great summary, Thank you, Sir!

    “Build it and if THEY (the Rads) never come…you and yours are still ok.”

  4. Pingback: For Your Planning Sessions… | The Defensive Training Group

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