radiation presentation for adh labs

7/28/2019 Radiation Presentation for ADH Labs

1/37

What is it?

Where is it?What is it doing?

How do we detect it?

What do we do about it?


2/37

Energy in motion in the form of waves orparticles.

3 common types and one less common

The (alpha) particle

The (beta) particle

(gamma) rays and X-raysAnd under certain circumstances

The neutron


3/37

The alpha particle is over 7000 times heavierthan the beta particle.

Being less massive and less charged than the ,

the interacts less with matter and has a muchgreater range.


4/37

Gamma & X radiation are a bit different innature than the preceding two types they area form of electromagnetic radiation with

characteristics of both particles and waves.


5/37

Unlike other forms of radiation, most x-rays inour environment are produced artificially byan electrical device, the x-ray tube. Whenturned off, no radiation is produced.


6/37

Usually only encountered in very specificenvironments at higher than background rate, suchas inside the containment vessel of a nuclearreactor, and thus not typically a risk to the general

public.

Only form of radiation capable of inducingradioactivity in nonradioactive materials(Exception is particle accelerators, where higher

energies can produce nuclear activation).


7/37

Radiation in some form is present everywhere,all of the time.


8/37

Total

background =

50%

Total medical =

48%

The total dose

to the average

individual has

increased 6X

since 1980,with of that

due to CT

scans


9/37

Radon is aradioactive gas thatis chemically inert.

Occurs as a resultof the decay ofnaturally occurringradioactiveminerals (Ra, U) inthe soil.

Depositsradioactive decayproducts in thelungs.


10/37

C.T. Scanner

24% yearly exposure

of average American


11/37

Brachytherapy Isotopes:

Cesium-137 Cobalt-60 Iridium-192 -Iodine-125 Palladium-103 Ruthenium-106 -


12/37

Linacs megavoltage x-rays, electron beam.

Cobalt Unit gamma knife.

Hadron Therapy proton, neutron, nuclei.


13/37


14/37

Nuclear Medicine Isotopes:Fluorine-18 +Gallium-67 Krypton-81m

Rubidium-82 +Technecium-99m Iridium-111 Iodine-123

Xenon-133 -Thallium-201 Yttrium-90 -Iodine-131 -


15/37


16/37

The Gas Chromatograph (GC) often uses aradioactive isotope, Ni-63, in a device called anElectron Capture Detector. It is a sealed source.


17/37

Radioactive chemicals in lead.


18/37

Radioactive chemicals in plastic.


19/37

Common emitters:

Americium-241 Smoke detectorsPolonium-210 Static eliminators

Common emitters:Tritium (Hydrogen-3) Luminous signsNickel-63 Piezoelectric generators

Common emitters:Cobalt-60 Food sterilizationIridium-192 Industrial radiography


20/37

Only radiation ofsufficient energy toknock electrons off ofatoms to produceions so-calledIonizing Radiation is regulated by theArkansas Departmentof Health.

This ionization, whenit occurs inside aliving organism, canseriously disrupt thecellular machinery.


21/37


22/37

and radiation, being particulate andcharged, have definite ranges in matter, basedupon the energy of the radiation and thedensity of the matter.

radiation and x-rays, however, beinguncharged electromagnetic radiation, haveonly a probability of interaction with matterthey pass through. We use the termattenuation, or weakening, instead of rangeto describe this condition. A given or x-raymay pass many feet before being absorbed.


23/37


24/37


25/37

Since particles lack the energy to penetrate theouter layer of skin, they are the least dangerousexternal radiation.

If an -emitting radionuclide is inhaled or

ingested, however, it is themost

dangerousinternal source of radiation. All of the particlesenergy gets dumped in a very short range oftissue, producing a very dense region ofionization.


26/37

Alexander Litvinenko, a former Russian agentwho defected to the UK, fell ill on November 1,2006, after having lunch with two former KGBagents. He died November 23 with the

symptoms of acute radiation poisoning. After his death it was determined that he had

ingested Polonium-210, probably in his tea atlunch.


27/37

Polonium-210 is an intense, almost pure alpha-emitter with a half-life of 138 days.

The almost complete lack of gamma emission

(1:100,000) makes it hard to detect, presumablya reason for its use as a poison.

It is such a powerful source that one gram ofPo-210 will self-heat to a temperature ofaround 500 C (932 F).

The main target organs are the spleen and liver.


28/37

The symptoms seen in Litvinenko appeared

consistent with an administered activity ofapproximately 2 GBq (50 mCi) whichcorresponds to about 10 micrograms of 210Po.That is 200 times the median lethal dose ofaround 238 Ci or 50 nanograms in the case ofingestion.

The particle energy is 5.307 Mev, which gives

a range of only about 0.05 mm in water.


29/37

Since ionizing radiation is what we are lookingfor, we use the ionization of matter as thesensing mechanism.


30/37


31/37


32/37

When in doubt, contact your Radiation SafetyOfficer!!!

Sherry Watkins 501-661-2922


33/37

Three Central Principles of RadiationProtection:

Time (Limit exposure time to the minimum)

Distance (Remember doubling the distancequarters the dose in a vacuum, not taking intoaccount the added shielding thickness)

Shielding (The denser the better for photonic,but not so much for or neutrons)


34/37

The Annual Occupational Limit for ExternalRadiation Exposure is the more limiting of:

A TEDE of 5 rem (0.05 Sv). The sum of the deep-dose equivalent to any

individual organ or tissue other than the lens of theeye being equal to 50 rem (0.5 Sv).

A lens dose equivalent of 15 rem (0.15 Sv). A shallow dose equivalent of 50 rem (0.5 Sv) to the

skin or any extremity.


35/37

Transport Index (TI) Dose rate at 1 meter from apackage. Different limits apply for different labels.


36/37

What is it? - Energy emitted in the form of waves

or particles.

Where is it? Everywhere within us and aroundus.

What is it doing? Knocking electrons off atomsand thereby disrupting biological function.

How do we detect it? By detecting itsionization of matter.

What do we do about it? Knowledge is power.


37/37

radiation presentation for adh labs

Documents