Can You Safely Handle Alpha Radiation? The Dangers of Unprotected Exposure

[Arjani]

Say I were to pick up a big chunk of Americium-241. Could I just hold it in my hand or would it be painful? Not that I'm planning on doing it, just out of curiosity.

 

[Astronuc]

One might feel warmth from the heat generated by the alpha activity, and possibly some tingling from the radiation. One would experience only alpha emitted from the surface adjacent to the hand, and they would be absorbed mostly by the skin.

http://www.nndc.bnl.gov/chart/reCenter.jsp?z=95&n=146 (use zoom 1)

http://www.nndc.bnl.gov/chart/getdecayscheme.jsp?nucleus=237NP&dsid=241am a decay&unc=nds
http://www.nndc.bnl.gov/chart/decaysearchdirect.jsp?nuc=241AM&unc=nds

About 84% of alphas are emitted with an energy of 5.486 MeV and another 13% have an energy of 5.443 MeV.

 

[Arjani]

Nothing more than tingling? So theoretically, you could hold it in your hand and if you just washed your hands thoroughly enough, you'd be none the worse off?

 

[silverback011]

Yes. I have done it, but I do not recommend it. I don't want to be held responsible if someone gets hurt doing this.

Most of the time when our people work with alpha particles they are wearing breathing protection to prevent internal intake as well as partial anti-contamination clothing. Also, sometimes the work is done in a glove bag if there is a large amount.

The primary hazard with alpha particles is if they are taken in internally. That is where they will do the most damage.

Google Alexander V. Litvinenko and Po-210. This unfortunate soul ingested Po-210 a known strong alpha emitter (I am unable to post links until I reach 10 posts). It was very big news at one time. Po-210 is used frequently in static eliminators if my memory serves me.

 

[silverback011]

I should clarify. I did not feel a 'tingling.' I did feel warmth from the decay or alphas depositing their energy in my skin.

Additionally, handling any radioactive material should be done with care. Alphas are considered not a large concern by many who work with radioactive material daily, but they can cause serious harm to you.

Just yesterday photos of a radiographer's hand came into my office from an overexposure. He will likely lose most of the digits on his hands. This is a person who has some training with handling radioactive materials and knows the risks. Admittedly the damage to his hands was not caused by alpha particles.

 

[Astronuc]

Nothing more than tingling? So theoretically, you could hold it in your hand and if you just washed your hands thoroughly enough, you'd be none the worse off?

There probably would be gamma radiation from the 3% of Am-241 with lower energy alphas, as well as decay products.

When handling Am-241 and other similar materials, one normally uses gloves and typically one works remotely or with the sample shielded in a glove box.

The transuranics are heavy metals so it's best not to handle with direct contact to the skin.

 

[terryphi]

I used to have a boss that said he could feel high energy gamma emitters in his fingers...not sure if a double blind study has been done on this or not.

 

[Bob S]

I used to have a boss that said he could feel high energy gamma emitters in his fingers...not sure if a double blind study has been done on this or not.

Cobalt⁶⁰ is 2.4 MeV per decay, so 1 watt of Co⁶⁰ = 1 Curie of Co⁶⁰. Absorption coefficient of Co⁶⁰ gammas in water is about 0.03 cm² per gram, so about the heating of fingers is about 1/30 of 1 watt, or 30 mW.

 

[DaveC426913]

I should clarify. I did not feel a 'tingling.' I did feel warmth from the decay or alphas depositing their energy in my skin.

Ah. I was about to comment. I would be astonished if one felt anything like tingling. One should just feel warmth. (But that is just an educated expectation.)

 

[daveb]

Cobalt⁶⁰ is 2.4 MeV per decay, so 1 watt of Co⁶⁰ = 1 Curie of Co⁶⁰. Absorption coefficient of Co⁶⁰ gammas in water is about 0.03 cm² per gram, so about the heating of fingers is about 1/30 of 1 watt, or 30 mW.

Um...really? First, the gamma decay energies for cobalt-60 are 1.17 and 1.33, which totals 2.5 MeV per decay (I'll ignore the other braches since they are so rare, as well as the beta energy). Second, 2.5 MeV is about 4 x 10^-13 J, and 1 curie is 3.7 x 10¹⁰ dps, which makes 1 Curie about 148 milliwatts. It takes about 6.76 curies to produce 1 watt of energy. I have no idea where you came up with 1 watt = 1 curie.

 

[Bob S]

Um...really? First, the gamma decay energies for cobalt-60 are 1.17 and 1.33, which totals 2.5 MeV per decay (I'll ignore the other braches since they are so rare, as well as the beta energy). Second, 2.5 MeV is about 4 x 10^-13 J, and 1 curie is 3.7 x 10¹⁰ dps, which makes 1 Curie about 148 milliwatts. It takes about 6.76 curies to produce 1 watt of energy. I have no idea where you came up with 1 watt = 1 curie.

My bad. Thanks.

 

[colindouglas]

If an alpha source is physically hot from it's own radioactivity, then you need to drop it and run. Any radioactive source that self heats is a source to run away from. Fortunately, you don't have to run far from alpha... gamma travels far further, although the inverse square law helps, air isn't a good shield for gamma.
I've had dealings with a single 4000 Ci cobalt 60 source that was described to me as roughly equivalent to a 60 watt lamp for heat. Two weeks of storage in a 2 tonne shielded pig (mostly lead) was enough to make the pig almost too warm to handle.
I've read that cats can detect strong xray and gamma fields by smelling the ozone created by ionisation of air in their nasal cavity. I can easily smell the ozone in a big gamma irradiator's canister when it is exposed long enough to kill all living cells in it. If I smelt that while working around a gamma source, I'd run and ask questions later. Immediate action might be your only chance of survival. If you could smell ozone, the gamma field would be enough to jelly your brains in a minute, so even a few seconds head start for bailing out could save your life. Never expose yourself to any radiation source unless you have training, shielding, handling rods, test instruments and a safety buddy. With two people, one doing the work, the other watching the instruments and cross checking your work, you have a much better chance of avoiding a nasty injury.