# Tritium Lights and You



## lambda (Dec 19, 2002)

I've seen a lot of interest in Tritium lights here on the CPF and have held my breath for sometime, but feel compelled to post a few things.

While I won't debate the safety issue directly (I'll leave that to someone else), I will relate a couple facts about Tritium lights just to ensure everyone is aware of them.

Fact # 1 - They leak; all Tritium lights outgas measurable levels of contamination. Even when enveloped in the finest glass or resin polymers money can buy, they still leak. Whether the resulting low level radiation is a hazard to you, or your family, is something you will have to decide for yourself. I do think it is important that you know and understand this fact, so that you can make an informed decision about ownership and usage. They leak.

Fact # 2 - In the US, Tritium is regulated by the NRC. Other than the very small Trijicon gun sights, all other Tritium lights require a license or permit to own or use. Violation of the NRC regulations can result in fines, but more importantly, may expose you to other legal liabilities. For instance, you could be held financially, or even criminally liable for any person or item contaminated by exposure to your light. Wipe tests on surfaces have detected the presence of Tritium even years after exposure. 

How safe or dangerous is Tritium? I don't know. I have pursued this issue in depth in conjunction with past endeavors, and the only conclusion I've made from that research is that nobody really knows the answer to that question. Little dedicated medical research has been done on Tritium, and out of what has been done, the results are inconclusive.

Most people dismiss Tritium radiation as benign, based on it's low energy level. Statements like "it won't even penetrate a piece of paper" are often seen in reference to Tritium radiation. While very accurate and true, it does not take in to account what happens when Tritium enters the human body. Unlike other radioactive isotopes, Tritium does not concentrate in, or affect any single part of the body. Where other isotopes are bone seekers, or collect in other organs of the body that make it easy to determine the effects of exposure to a particular isotope, Tritium generally evenly distributes itself throughout the human body. This is one reason for a less than definitive answer to what the long term effects of Tritium expose can be. 

Tritium is radioactive hydrogen. You cannot use a Geiger counter to detect Tritium radiation.

It also has a nasty habit of replacing the H in H2O resulting in essentially radioactive water (tritium oxide), which is a generally recognized contamination hazard. One piece of equipment I worked with in the past was an optical device with a 10 curie Tritium lamp. Typical sphere lamp, glass with phosphor coating inside, about 5/8" diameter; like a glowing marble. This device was used outside, so it also had a desiccant in it to collect moisture to keep the lenses from fogging up. Small desiccant cartridge was replaced every six months. Desiccant liquid scintillation test readings were typically in excess of 1,000,000 dpm (disintigrations per minute) after 6 months in the device with the tritium lamp. For reference, 100 dpm and below is what is still allowable for a device and be considered "clean" for the general public. Military items usually are considered "clean" for hand held use at 1000 dpm and below, and 10,000 dpm and below for other equipment. 
The desiccant contamination levels were 1000 times the allowable levels. The maintenance people who changed the desiccant did it bare handed, without any knowledge of any potential contamination. Tritium is like invisible sticky glue; if you handle a contaminated item then shake hands with someone, their hand will also be contaminated. Get the idea? 

Whether it's harmless or not, I won't debate, but it can be spread in measurable levels by simple physical contact. 

(They do not change the desiccant that way anymore, and the devices are being upgraded to use an LED and battery in place of the Tritium lamp) (duh)

Is Tritium safe? Again, I don't have the answer, but if you own a Tritium lamp, chances are a wipe test will detect "some" level of contamination. If you want to check your glow ring or other Tritium lamp source, look for testing labs on the web that can do liquid scintillation testing. It's simple and easy to do, and should not be very expensive. You will get a bottle with some distilled water in it, and some dry filter paper. Wipe the dry filter paper all over the outside surface of the lamp and then drop into the water, seal the bottle and send back to lab. You should have results in a couple weeks. 

I know I've opened the proverbial can of worms here, but my experience has shown that Tritium devices are self-contaminating, and thought I had to say something. Again, is it safe? I don't know............


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## James S (Dec 19, 2002)

I'm not arguing the point, just curious what device you were working on that had a big glowing marble in the middle? That sounds like something I want to avoid at ham fests or while scrabbeling through old electronics/medical auction stuff!


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## browntown (Dec 19, 2002)

tritium, H-3, is radioactive, but is only a beta emitter, with a half-life of 12.28 years, but Biological Half-Life: 10 - 12 days

Effective Half-Life: 10 - 12 days*

* Forcing liquids to tolerance ( 3-4 litres/day ) will reduce the effective half-life by a factor of 2 or 3.

so yes with water it can enter the human body, but you going to suck on your light? Even with accidental exposure it is easily dilluted

back in the day the stocker and yale tritium military lensatic compasses had a big radioactive shield on the back, like you were walking around with uranium. now they say "phosporous"

h-3 is so minor that ppl working with it arent even required to were dosimeters.

The contamination limit is 3000 dpm/100 cm2 for smear surveys and really not a concern for a well manufactured sealed unit. are glowrings well manufactured? up to you.

for handling direct tritium, gloves are about all thats required, probably a mask for safety too. I certainly wouldnt switch out those dessicant packs bare-handed.

just thought I'd add to the info. I side with lambda though that it is your decision, and am not arguing any of his points. However, in my experience, there's a lot more worrisome things in this world.


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## lambda (Dec 19, 2002)

James S,

You don't have to worry; NRC licensed device; requires special disposal to get cleared from the license. Accountable by serial number and periodic testing for contamination levels. 

browntown,
"However, in my experience, there's a lot more worrisome things in this world"

Agree, insecticides and spray paint mist inhaled are probably more dangerous.


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## James S (Dec 19, 2002)

OK, so I'm not worried, but I'm still curious!

I have a lot more black flag around here than I do tritium. But I heard that the river in Savannah has a higher than usual level of deuterium and tritium contamination due to a military processing plant upstream...


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## rlhess (Dec 19, 2002)

By the way, the way some of the nuclear regulations are written -- using the concept of ALARA (as low as reasonably achievable--I think that's what it stands for)-- has people doing radiation cleanup that causes the cleaned site to have lower radiation than normally just sitting around in your living room. In fact, as I understand it, special measurement techniques need to be used in order to find the traces that have to be cleaned. It's very expensive to have to do this. I would heed Lambda's cautions.

The ALARA-based regulations seem to be more based on what's possible as opposed to what's needed. There may have been instances where far too much money has been spent cleaning things that didn't need to be quite so clean based on known and even speculated health effects.

By the way, I've learned a little about this field as I've joined up with a group of health physicists online and they've been very generous in helping teach me things. I came to the mailing list trying to learn more about some of the risks we're exposed to and have now developed a sense that many of the purported risks are not as bad as they're made to seem in the media.

Still, I wouldn't violate any of the nuclear regulations and run the civil risks of having to clean up the mess.

Cheers,

Richard


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## Wulong (Dec 19, 2002)

Thanks for the info Lambda.

I've been holding off on the Tritium products for quite awhile...think I'll continue to do so. 

That money would be better spent on one of your mods anyway.


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## Josh (Dec 19, 2002)

I had an orange old style that I lost for a couple of days and when I got it back the borsilicate(spelling?) tube was in 3 pieces!. The outter casing is ok, but it looke like it may have got very very cold and just expanded,wierd.


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## Saaby (Dec 19, 2002)

I've said it once, now I'll say it again...

Don't tell the feds, but I've got a glowring on my keys. My keys reside in, well, my pocket. They're there a minimum of 3 hours and often as many as 15 hours a day.

I'll let you know if my kids turn out to be mutants.

My question is this:
If it's virtually undetectable, how are the feds going to find out you have the glowrings? Sneak in your house durring the day and do swipe tests?


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## Wits' End (Dec 20, 2002)

I had a long post typed out and my computer crashed



. Maybe the Lord telling me not to be proud of my opinion .
Quick and short.
Everyone makes choices as to how much risk to take and what risks are worth it. My wife 'had a bad feeling' about glowrings. I respect those bad feelings so I got rid of the ones I had. This post confirms valid reasons for those bad feelings.
On a lighter note




I have been exposing myself to DiHydro Monoxide in flux between it's solid and liquid phase lately. Though I have suffered bodily injury from this before I choose to continue to take the risk. I hope I live to not regret it.


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## FlashBulb (Dec 20, 2002)

Gosh, I've always wanted a glowring. Now I'm not so sure. I've always assumed tritium was pretty benign (being beta radiation and all), but it's this swipe test business doesn't encourage me.

Lambda -- You say they ALL leak. Are you sure? I can't see why this is necessarily true.

Whether or not tritium is dangerous, you should all be careful around Dihydrogen Monoxide. Thank you <Wits" End> for broaching the subject. That stuff can be pretty nasty, especially if you get it in your lungs.


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## Wits' End (Dec 20, 2002)

I have more experience with the DHMO under my feet. When it is in its crystaline, powdery form it isn't bad. When it is a solid with a layer of liquid that is very dangerous.


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## lambda (Dec 20, 2002)

> Originally posted by FlashBulb:
> [QB]
> Lambda -- You say they ALL leak. Are you sure? I can't see why this is necessarily true.
> QB]


<font size="2" face="Verdana, Arial">I base my statement on experience with several thousand devices tested, all showed signs of self-contamination. Most, but not all, were in the million+ count area.

And we usually have a surplus of Dihydrogen Monoxide around here this time of year. If anybody want's some, I can shovel it into a box for them.....


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## MichiganMan (Dec 20, 2002)

> Originally posted by browntown:
> I side with lambda though that it is your decision, and am not arguing any of his points. However, in my experience, there's a lot more worrisome things in this world.


<font size="2" face="Verdana, Arial">Being the worrisome person I am, his point about liability and how contamination can be detected by a simple test years after exposure makes me think that even if Tritium isn't dangerous it can still pose a significant threat to me.

Consider a work area (ie. your desk) that comes into daily contact with your keys, now say you're promoted/moved or otherwise persuaded to leave your work area ("I didn't _lose_ my job, I know where it is, there's just someone else doing it now..."



) 

Now imagine the not completely unlikely occurance that the person who replaced you at that work area comes down with one of the many cancers that people can get. Being a human, the person will search for a cause, a reason that they were so unfairly afflicted with the cancer and someone will remember that noticeable "radioactive" keychain you always had in there. One smart lawyer and a wipe test later and you're in the uncomfortable position of trying to prove, in a very unscientifically minded courtroom, that you're not responsible for this persons cancer.


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## Glow Bug (Dec 20, 2002)

Here is a link to little more info on Tritium.. http://www.stoller-eser.com/Quarterlies/tritium.htm


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## krept (Dec 20, 2002)

re: DHMO... but guys, if it doesn't glow, what good is it?

I wish it were as easy to get those little capsules that they put in night sights as it is to get Glowrings... think of the flashlight and knife mods you can do with a little dremel and epoxy


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## sunspot (Dec 20, 2002)

Briefly, what is DHMO used for?

krept. If you have a bud in the UK, the little capsules can be had. Go to www.traser.com for all the different sizes.
BTW, your idea has been kicked around before but nobody did anything with it.


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## tiktok 22 (Dec 20, 2002)

Hi Wit,

Over exposure to dihydrogen oxide is a leading cause of death on this country..........swimming pools can lead to drowning!!!!!


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## Vikas Sontakke (Dec 22, 2002)

> Originally posted by Saaby:
> *I've said it once, now I'll say it again...
> 
> I'll let you know if my kids turn out to be mutants.
> ...


<font size="2" face="Verdana, Arial">Well Saaby, the question should be *if* you have kids ... 

- Vikas


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## Gandalf (Dec 22, 2002)

I've seen a lot of interest in Tritium lights here on the CPF and have held my breath for sometime, but feel compelled to post a few things.

While I won't debate the safety issue directly (I'll leave that to someone else), I will relate a couple facts about Tritium lights just to ensure everyone is aware of them.

Fact # 1 - They leak; all Tritium lights outgas measurable levels of contamination. Even when enveloped in the finest glass or resin polymers money can buy, they still leak. Whether the resulting low level radiation is a hazard to you, or your family, is something you will have to decide for yourself. I do think it is important that you know and understand this fact, so that you can make an informed decision about ownership and usage. They leak.
-

>>Actually, this is only partially true. They do leak, but at a very, very tiny rate. Hydrogen, or tritium gas, is difficult to contain. Even in glass, is VERY slowly diffuses through. But if you start out with a small amount of tritium, and this includes Glowrings and firearm night sights, the leakage is so small as to be immeasurable. It disperses by diffusion *immediately* upon escaping the glass envelope. It doesn't sit on the surface, waiting to be 'picked up' and 'spread around', or 'ingested'.
-

>>I've worked with tritium, and many other radioactive isotopes, for decades now. It's simply not very dangerous at all to work with. I wear latex gloves; no shielding is required.

Fact # 2 - In the US, Tritium is regulated by the NRC. Other than the very small Trijicon gun sights, all other Tritium lights require a license or permit to own or use. Violation of the NRC regulations can result in fines, but more importantly, may expose you to other legal liabilities. For instance, you could be held financially, or even criminally liable for any person or item contaminated by exposure to your light. Wipe tests on surfaces have detected the presence of Tritium even years after exposure. 
-

>>Not tritium is the gaseous form, as found in Glowrings and night sights; it simply disperses immediately into the atmosphere.

How safe or dangerous is Tritium? I don't know. I have pursued this issue in depth in conjunction with past endeavors, and the only conclusion I've made from that research is that nobody really knows the answer to that question. Little dedicated medical research has been done on Tritium, and out of what has been done, the results are inconclusive.

Most people dismiss Tritium radiation as benign, based on it's low energy level. Statements like "it won't even penetrate a piece of paper" are often seen in reference to Tritium radiation. While very accurate and true, it does not take in to account what happens when Tritium enters the human body. Unlike other radioactive isotopes, Tritium does not concentrate in, or affect any single part of the body. Where other isotopes are bone seekers, or collect in other organs of the body that make it easy to determine the effects of exposure to a particular isotope, Tritium generally evenly distributes itself throughout the human body. This is one reason for a less than definitive answer to what the long term effects of Tritium expose can be. 

>>The fact that tritium disperses through the body, rather than collects in a specific organ, as radioactive iodine does in the thyroid, is a major factor making it very safe to work with. 

Coupled with it's EXTREMELY LOW ENERGY beta emissions, it is arguably the safest isotope in existence to work with.

And, even inside the body, it is still an extremely low energy beta emitter. Dispersed through the body, and excreted in urine, it poses EXTREMELY little risk; and in the amounts found in Glowrings and night sights, simply no risk at all.

Tritium is radioactive hydrogen. You cannot use a Geiger counter to detect Tritium radiation.

It also has a nasty habit of replacing the H in H2O resulting in essentially radioactive water (tritium oxide), which is a generally recognized contamination hazard. One piece of equipment I worked with in the past was an optical device with a 10 curie Tritium lamp. 

>>This is an ENORMOUS quantity of tritium to be found in one place. You are talking about MORE THAN 4 ORDERS OF MAGNITUDE (>10,000 times) greater than what's found in Glowrings and night sights. This HUGE quantity of tritium is NEVER going to be encountered by the public at large.

Typical sphere lamp, glass with phosphor coating inside, about 5/8" diameter; like a glowing marble. This device was used outside, so it also had a desiccant in it to collect moisture to keep the lenses from fogging up. Small desiccant cartridge was replaced every six months. Desiccant liquid scintillation test readings were typically in excess of 1,000,000 dpm (disintigrations per minute) 

>>1,000,000 DPM is equivalent to 0.0000000005% of the contents of the 10 curie lamp, by my calucalations of approx 200,000 DPM per MICROCURIE of tritium;10 CURIES is 10,000,000 MICROCURIES. This reflects the extremely LOW rate at which tritium diffuses through a glass envelope.

after 6 months in the device with the tritium lamp. For reference, 100 dpm and below is what is still allowable for a device and be considered "clean" for the general public. Military items usually are considered "clean" for hand held use at 1000 dpm and below, and 10,000 dpm and below for other equipment. 
The desiccant contamination levels were 1000 times the allowable levels. The maintenance people who changed the desiccant did it bare handed, without any knowledge of any potential contamination. Tritium is like invisible sticky glue; if you handle a contaminated item then shake hands with someone, their hand will also be contaminated. Get the idea? 

>>The notion that you could 'spread' contamination of the gas form of tritium from hand to hand is, on the face of it, simply impossible. Hydrogen, or tritium, in it's elemental form, doesn't 'stick' to human skin.

As for ingestion of elemental tritium, remember, we are talking about hydrogen gas. You have to inhale it, to get it into your body.

Whether it's harmless or not, I won't debate, but it can be spread in measurable levels by simple physical contact. 

(They do not change the desiccant that way anymore, and the devices are being upgraded to use an LED and battery in place of the Tritium lamp) (duh)

Is Tritium safe? Again, I don't have the answer, but if you own a Tritium lamp, chances are a wipe test will detect "some" level of contamination. If you want to check your glow ring or other Tritium lamp source, look for testing labs on the web that can do liquid scintillation testing. It's simple and easy to do, and should not be very expensive. You will get a bottle with some distilled water in it, and some dry filter paper. Wipe the dry filter paper all over the outside surface of the lamp and then drop into the water, seal the bottle and send back to lab. You should have results in a couple weeks. 

I know I've opened the proverbial can of worms here, but my experience has shown that Tritium devices are self-contaminating, and thought I had to say something. Again, is it safe? I don't know............
-

Glowrings are allowed in all, or most, of the European Union. Night sights are allowed in all of the United States. There simply is NO RISK AT ALL associated with this VERY TINY quantity of elemental tritium. End of story.


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## J Smith (Dec 22, 2002)

All I have to say is this.I live near oakridge Tn and I am more worried about walking around in the woods and drinking the water from my tap than carrying a glowring.I now for a fact that there is a tree in oakridge that will give you a dose of radiation equal to a chest xray if you hug it for 30 seconds.


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## Avatar (Dec 23, 2002)

Bring on the MF'n tritium lights! No EECS, just reliable nuclear power! Thats what I want.


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## Jonathan (Dec 25, 2002)

Gandalf, 

I agree with most of what you are saying, but I think that you are wrong in some details. Lambda's post on this topic struck me as doing a good job of describing dangers without fearmongering, so that people can evaluate their own risks; I hope to continue in this vein.



> Originally posted by Gandalf:
> *Actually, this is only partially true. They do leak, but at a very, very tiny rate. Hydrogen, or tritium gas, is difficult to contain. Even in glass, is VERY slowly diffuses through. But if you start out with a small amount of tritium, and this includes Glowrings and firearm night sights, the leakage is so small as to be immeasurable. It disperses by diffusion *immediately* upon escaping the glass envelope. It doesn't sit on the surface, waiting to be 'picked up' and 'spread around', or 'ingested'.
> *


<font size="2" face="Verdana, Arial">Also not _quite_ correct. It is true that elemental tritium will simply disperse rapidly in the atmosphere. However it is also well known that hydrogen exchanges pretty darn rapidly. If elemental tritium were to come in contact with water (none of that around




), then the tritium _will_ exchange with the hydrogen in the water to produce water molecules with tritium present. This won't disperse so rapidly.

One bit of actual peer reviewed medical research done was about human exposure to tritium based upon wearing a plastic bodied watch with tritium _paint_ on the hands. The tritium gas would get into the body of the watch and then diffuse through the case to the wearer. This is significant to the discussion because we are talking about similar quantites of tritium and similar 'keep on the body' use.
(Do a google search for 'tritium exposure plastic watch' and you will find several articles which reference this one)

In any case, the result of this study was that a person _wearing_ such a watch was getting an additional radiation dose of about 1% of normal background.



> Originally posted by Gandalf:
> * </font><blockquote><font size="1" face="Verdana, Arial">quote:</font><hr /><font size="2" face="Verdana, Arial">Originally posted by Lambda One piece of equipment I worked with in the past was an optical device with a 10 curie Tritium lamp. *


*<font size="2" face="Verdana, Arial">This is an ENORMOUS quantity of tritium to be found in one place. You are talking about MORE THAN 4 ORDERS OF MAGNITUDE (>10,000 times) greater than what's found in Glowrings and night sights. This HUGE quantity of tritium is NEVER going to be encountered by the public at large.
*</font><hr /></blockquote><font size="2" face="Verdana, Arial">I think that you slipped an order of magnitude




The amount permitted in watches is 25mCi of Tritium. I don't know how much is in a glowring. Thus the 10 Ci source was 400x more than what is allowed in a watch.



> Originally posted by Gandalf:
> *>>1,000,000 DPM is equivalent to 0.0000000005% of the contents of the 10 curie lamp, by my calucalations of approx 200,000 DPM per MICROCURIE of tritium;10 CURIES is 10,000,000 MICROCURIES. This reflects the extremely LOW rate at which tritium diffuses through a glass envelope.*


<font size="2" face="Verdana, Arial">Another magnitude slip



1 Curie is 3.7x10^10 disintegrations per second. This works out to 2.2x10^6 disintegrations per minute for a uCi. This means that what was detected in the desiccant was about 0.5uCi, or about 0.000005% of the original contents. Since there was desiccant here, but it was only changed every 6 months, we can presume that this was a sealed case and that any tritium which escaped was held around until it did exchange into the water.

If we presume similar leakage rates for glow rings, figuring the lower _volume_ of the glow ring means more surface area per unit volume (and thus greater fractional leakage), that I guesstimate that a glow ring will leak about 0.002uCi per year. Perhaps someone could contact the company that makes them and see what figure they use.

Note the following: when animals are used in studies that involve feeding them tritium tagged compounds, they can be disposed of as 'not radioactive' if they contain less than 0.05uCi per gram.

IMHO the biggest risk is _not_ from the Glow Ring itself, but the _legal_ risk that Lambda pointed out. Radiation levels that are well below what one might reasonably consider safe are easily detectable (this ease of detection is precisely _why_ people like using isotopes for study). 

-Jon


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## MR Bulk (Dec 25, 2002)

I have tritium markers on my keyring and next to the light switch in my pitch black light mod work shed so I can find it when I go inside. And then this evening I looked down and noticed I have six toes on my left foot -- Hmmm...


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## e=mc² (Dec 25, 2002)

Grow up people! We're talking about 200 microcuries here. And that's per glowring. How many hundreds of thousands of glowrings it would take to equal 1 curie. A single glowring, even measured with the most sensitive of dosimeters, would be lost to background radiation! I live in the same county where thay filmed "Toxic Avenger" several



years ago, and nobody in our county has been "nuked" if you pardon the expression. No mutants, with the possible exception of our local chemist, exist that we know of.

Ed.


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## Jonathan (Dec 25, 2002)

> Originally posted by e=mc²:
> *Grow up people! We're talking about 200 microcuries here.*


<font size="2" face="Verdana, Arial">Could you point me to the spec that provides the total amount of tritium? I was under the impression that watches used 25millicuries.

-Jon


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## Streak (Dec 26, 2002)

To put things into perspective, please read the following taken from a document from a manufacturer of GTLS's. They say that destroying a safety sign containing 30 Curies of tritium will expose you to the tiniest amount of exposure. I would go so far as to say that the .0001 mSv they talk about is less than the amount of background radiation you will receive when standing outside on a sunny day!!

Ionising radiation is part of our natural surroundings and always has been. The natural sources of radiation include minerals in the earth, radioactive gases in the air, cosmic rays from outer space and the sun, all of which are referred to as "natural background" radiation. Some manufactured products such as building materials and luminous paints as well as our food and water, contain small quantities of radioactive material. For many years X-rays have been produced artificially for medical applications. 
When a person is exposed to radiation, the body absorbs some of the ionisation dose. Two units for dose measurements are currently in use. The conventional measure is the rem, but this unit is being replaced by the Sievert (Sv) and 1 Sievert = 100 rem. It is usual to refer to dosages in terms of millirem (abbreviated as mrem) or milliSievert, mSv (milli = 1/1000).

It is useful to compare doses received by humans due to radiation exposure from different sources encountered in everyday life.

Type of Radiation Exposure
Dose, (mSv)

Natural background dose per person depending on geographical position Medical X-ray Examination
1 to 3,5 per year

Chest
0,06

Skull
0,20

Spinal Column
1,30

Upper Gl
2,45

Abdomen
0,55

Barium Enema
4,05

Pelvis
0,65

Bone Fracture
0,01

Radioluminescent Light Sources - through complete destruction of all tubes in a Safety Sign to effectively release all the tritium contained (34 Ci) a worst case scenario
0,0001 or less.

http://www.worst4x4.freeservers.com


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