[ RadSafe ] Demo to show exposure vs. contamination

Wed Aug 27 18:28:23 CDT 2008

Louis,

Here is a simple, visual demonstration you can use with your HazMat
students.

I have found that many of our students (adult emergency responders) have
some difficulty with the concept of radiation exposure vs.
contamination.

We have developed a simple but effective demonstration using a chemical
glow stick. We use this demo with thousands of students (HazMat
Technicians, Fire Fighters, Law Enforcement Officers, Emergency Medical
Services, and other emergency responders) every year, and the feedback
from the students and instructors has shown this to be a big help. This
demo does not address neutron activation and other methods of creating
radioactive material because those topics tend to confuse the students
ever more at this stage of learning.

Demonstration using a chemical light stick or flashlight.

A chemical light stick is preferred, but you can present this
demonstration by using a flashlight. The ultra-high intensity chemical
light sticks work best (brighter), but standard chemical light sticks
work fine. 

This demonstration explains radiation exposure (irradiation) vs.
contamination and radioactive material particles vs. radiation. Some
students may think that exposure to radiation will contaminate people or
objects. Many students also get confused and initially think that
radiation particles such as beta or alpha particles behave like
particles of dust or droplets of liquids, leading them to mistakenly
think that someone inhales alpha particles to get internal contamination
or beta particles penetrate protective suites and contaminate the
person's skin (wrong). Another mistaken idea is that you cannot be
contaminated by gamma (gamma-emitters) because gamma rays are a wave,
and therefore you do not need protective respirators for any
gamma-emitting sources (wrong). These ideas come from their experiences
with chemical hazards and not differentiating between radioactive
material and radiation. This is one reason why we refer to "alpha
radiation, beta radiation, gamma radiation, and neutron radiation"
instead of "alpha particles, beta particles, gamma-rays, and neutron
particles." For most emergency response tasks, the personnel deal with
radioactive material and the radiation from it without needing to think
about the particle or wave nature of radiation itself.

For this demonstration, pretend the chemical light stick is a tiny dust
speck of radioactive material, such as plutonium, and the light is the
radiation. The glowing atoms inside the source simulate radioactive
atoms. (Remind the students that the chemicals in a light stick are not
radioactive.).

1.	Turn down the lights in the room.
2.	Hold the light stick in front of your left hand such that the
students can see the light stick, your left hand, and illumination on
your left hand.
3.	Move the glow stick away from your left hand and set it on a
table (out of the way).
4.	Show that your hand does not glow or emit light when you take it
away from the light source; therefore, your hand was exposed
(irradiated), not contaminated. Radiation does not build up on a person
or thing and make it radioactive. The actual radioactive atoms in the
form of dust, gas, or liquid must move onto an object to contaminate it.
When we talk about radioactive particles causing contamination, it means
that small particles of dust or liquid containing radioactive atoms are
present on an object.
5.	Discuss (do not actually perform) that if you cut open the
chemical light and spill the liquid on your left hand, your left hand
will be contaminated. (The actual radiation-emitting atoms are now on
your hand.) The radioactive material now on the skin of your left hand
would also be exposing (irradiating) your hand.
6.	Now, pick up the light stick again and show the light stick
floating through air (supported by your hand). Say the light stick
(particle of radioactive material) is floating in the wind.
7.	Show the radiation (light) is emitted in all directions, even
against the wind. The airborne radioactive material is blown by the
wind, but radiation may expose (irradiate) individuals upwind. Standing
upwind from radioactive materials does not protect you from radiation
exposure.
8.	Pretend to inhale the radioactive material speck (move light
stick toward your mouth). Show that you don't inhale the radiation
(light) itself. This is true if the radiation is alpha, beta, gamma, or
neutron radiation. You cannot inhale alpha particles, but you can inhale
particles of plutonium dust, and those plutonium particles emit alpha
radiation (alpha particles).

Hope this helps.

Another good training aid radiation exposure vs contamination is the
short (2 minutes) video Radiation Principles from the Centers for
Disease Control and Prevention (CDC), Radiation Studies Branch (RSB) 

www.bt.cdc.gov/radiation

rsb at cdc.gov

404.498.1800

This video can also be watched or downloaded at the Radiation Event
Medical Management (REMM) website

http://www.remm.nlm.gov/radprinciplesvideo.htm

Hope this helps.

Best regards,

Rick Hansen

Senior Scientist

Counter Terrorism Operations Support Program (CTOS)

National Security Technologies, LLC, for the U.S. Dept of Energy

hansenrg at nv.doe.gov <mailto:hansenrg at nv.doe.gov> 

www.nv.doe.gov/nationalsecurity/homelandsecurity/responder.htm
<http://www.nv.doe.gov/nationalsecurity/homelandsecurity/responder.htm> 

Message: 4

Date: Tue, 26 Aug 2008 11:08:56 +0000

From: "Louis N. Molino, Sr." <LNMolino at aol.com>

Subject: Re: [ RadSafe ] "exposure" to radiation in other languages

To: "Radsafe" <radsafe at radlab.nl>

Message-ID:

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2- at bxe151.bisx.prod.on.blackberry>

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For the past 3 weeks I've been teaching HAZMAT here in Baku, Azerbaijan.
The single most difficult point/concept I've dealt with has been the
idea of exposure. Why did you all wait this long to have all this
conversation! 

LNM from Baku, Azerbaijan

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