# Unexpected Health Hazard



## Roamer Man (May 25, 2011)

Been pondering recently about possible hazards with restoring early dials in connection with the type lume they used. Up until the early 1960s(?) dials used radium. After checking Wikipaedia, I'm left wondering should we vintage fans be concerned at all?

I suppose we're all aware of the Canadian experience in watch and clock factories in the 1950s. Workers doing the dial lume were dropping like flies after licking the brushes for painting on the lume! 50 years on you have to ask the question - are these dials still dangerously radio-active?

According to Wiki the half-life of radium depends on the isotope, of which there are many. It vary in half-life between approx. 6 years to 1600 years. If the isotope used was the latter one, then the radioactivity is still high even after 50 odd years.

In retrospect, I'm wondering now if someone were to check my work surfaces, bins, drains and me with a geiger counter, would it show as 'hot'?

So here's the question - what isotope was used, if anybody even knows?

P.S. Anyone got a geiger counter they can lend me?


----------



## tall_tim (Jul 29, 2009)

Different but similar...

http://www.thewatchforum.co.uk/index.php?showtopic=68877&hl=radiation&fromsearch=1

I have also heard of a case up here, whereby a watch repairer died and SEPA and HSE were called in as the house was practically glowing through the sheer number of old dials he had.


----------



## AbingtonLad (Sep 8, 2008)

Yup, we've had this topic before. My Mrs Wife is a physicist and assured me that, short of swallowing lumed dials there's really no significant danger. And even if you swallowed one the danger from obstruction would far outweigh any risk from radiation.

It's not so much about the half life of the material, but the kind of particle it emits. Here we are dealing with alpha particles, which are the least energetic of the three possible types (beta and gamma being the other two). Normal air is often sufficient to stop alpha particles and skin will certainly do the trick.

It is, however, a very bad idea to stick a paintbrush into a pot of luminous paint, lick it, and then repeat the process several hundred thousand times.


----------



## Roamer Man (May 25, 2011)

tall_tim said:


> Different but similar...
> 
> http://www.thewatchf...on&fromsearch=1
> 
> I have also heard of a case up here, whereby a watch repairer died and SEPA and HSE were called in as the house was practically glowing through the sheer number of old dials he had.


Probably not so dissimilar if they used radium 226 (half-life 1620 years). Mind you, does the fact they've stopped glowing mean they're not radioactively so 'hot' any more? Also the quantity used probably amounts only to micrograms in a watch. They probably used loads more in aircraft instruments?

All the same it's bit of a worry..but we don't know what old watch repairer died of, or how many old dials he actually had?


----------



## Roamer Man (May 25, 2011)

AbingtonLad said:


> Yup, we've had this topic before. My Mrs Wife is a physicist and assured me that, short of swallowing lumed dials there's really no significant danger. And even if you swallowed one the danger from obstruction would far outweigh any risk from radiation.
> 
> It's not so much about the half life of the material, but the kind of particle it emits. Here we are dealing with alpha particles, which are the least energetic of the three possible types (beta and gamma being the other two). Normal air is often sufficient to stop alpha particles and skin will certainly do the trick.
> 
> It is, however, a very bad idea to stick a paintbrush into a pot of luminous paint, lick it, and then repeat the process several hundred thousand times.


So it's alpha particles. Your wife's info puts it into perspective somewhat. Thanks Kevin, much appreciated (and I don't have to go for a detox and find a new hobby!)

Sounds like HSE was going a bit OTT in Scotland, as usual!


----------



## William_Wilson (May 21, 2007)

AbingtonLad said:


> Yup, we've had this topic before. My Mrs Wife is a physicist and assured me that, short of swallowing lumed dials there's really no significant danger. And even if you swallowed one the danger from obstruction would far outweigh any risk from radiation.
> 
> It's not so much about the half life of the material, but the kind of particle it emits. Here we are dealing with alpha particles, which are the least energetic of the three possible types (beta and gamma being the other two). Normal air is often sufficient to stop alpha particles and skin will certainly do the trick.
> 
> It is, however, a very bad idea to stick a paintbrush into a pot of luminous paint, lick it, and then repeat the process several hundred thousand times.


You are speaking of tritium, not radium. Check with your wife again. Radium emits all three particles, alpha, beta and gamma.

Here are a couple of interesting videos:











Later,

William


----------



## Roamer Man (May 25, 2011)

William_Wilson said:


> AbingtonLad said:
> 
> 
> > .. And even if you swallowed one the danger from obstruction would far outweigh any risk from radiation...It's not so much about the half life of the material, but the kind of particle it emits. Here we are dealing with alpha particles, which are the least energetic of the three possible types (beta and gamma being the other two).
> ...


OK, so now I'm worried again. Do you know which of the three radioactive particles produces the luminescence, and if 50 year-old lume has faded, is it no longer dangerously 'hot'?

I understand that lume is/was at a higher temperature than ambient because of the heating effect of the radiation.


----------



## gaz64 (May 5, 2009)

Beta particles are able to penetrate living matter to a certain extent and can change the structure of struck molecules. In most cases such change can be considered as damage with results possibly as severe as cancer and death. If the struck molecule is DNA it can show a spontaneousmutation.

Beta sources can be used in radiation therapy to kill cancer cells.

Ingested particles that emit beta radiation would not be good. Dalgety bay has a problem because of radium from old aircraft instruments.


----------



## William_Wilson (May 21, 2007)

An alpha emitter of sufficient strength can deliver more energy to tissue than beta or gamma, but alpha emitters have very limited penetration, thus the need for ihalation or ingestion. Gamma rays are basically X-rays and have a great deal of penetration. While an alpha won't penetrate the skin, the gamma coming off some radium compounds will penetrate a watch's case.

A safe bottom line to all of this is to inhale or ingest no radium, tritium or promethium compounds at all. As far as radium watches go, don't wear them all of the time or store them in a place that you spend a great deal of time. A further point, tritium and promethium watches used closely regulated strengths in their compounds. Radium watches varied quite a bit. It's not unusual to see radium watches with scortch marks from the radiation.

Later,

William


----------



## Roamer Man (May 25, 2011)

William_Wilson said:


> ..A safe bottom line to all of this is to inhale or ingest no radium, tritium or promethium compounds at all.
> 
> Later,
> 
> William


William, as ever you're a mine of technical information, but I'd be surprised if many of us vinatge tinkerers have not ingested/inhaled at least some of the above, hopefully not too much of the radium. I just checked all my watches, and I've got several with Pm (as stated on the bezel) and I have three pairs of hands suspiciously glowing all the time. I guess these would be the radium variety, which I shall treat with great caution.

One pair is from a not-very-vintage Sekonda. I guess the Ruskies weren't too fussed about potential health hazards until after 1989.

But I'm not going to worry myself to death at my age, not when I survived the days when we used to spray rooms with DDT to kill flies (dissolved in paraffin and sold as 'Flit' guns). Makes one shudder to think what we were exposed to in those days!


----------



## Mr Whimpy (Jan 14, 2012)

Wow that first video clip is worrying

I can't say I know a great deal about the subject but it does make for a great insight into what's on your wrist

What I would like to know if possible is does this cause a concern for the wearer of a vintage watch over a long period of wear or is this more a subject of worry for everyone who is restoring watches and being exposed to the particles through contact of the watch face/dial/mechanism on a constant basis ?

I'm looking at buying an early watch at the moment to wear but this strikes a chord of concern to be honest

Cheers


----------



## Roamer Man (May 25, 2011)

Mr Whimpy said:


> Wow that first video clip is worrying
> 
> I can't say I know a great deal about the subject but it does make for a great insight into what's on your wrist
> 
> ...


I can see your problem. I suppose it boils down to 'safely' removing the original lume. That would involve a rubber gloves and mask job, at the very least. The problem is then how to dispose of the offending matter? It would be no good flushing it down the loo, and don't even think of burying it in a very deep hole in a thick lead container. It would still eventually leak into the ground water (and that's probably illegal). Whatever you try, you'd probably end up contaminating you surroundings, whatever precautions you take.

I've only worked on half a dozen suspect dials, but I'm pretty certain by now I've contaminated every room in my house, and the drainage system, albeit minutely. Also, if I was to take a scraping of my finger nails, it would show geiger-positive - which means I've also ingested it ('scuse me while I take my last croak)!

Best do as advised above by William, don't wear the watch too much.


----------



## Mr Whimpy (Jan 14, 2012)

Defeats the objective of owning an old timepeace for me

Hmmm maybe I'm overreacting a little and jumping the gun

If this was a great concern surely it would have come to light sooner and would have been a healh n safety issue no ?

I mean in this day n age would it not have been researched and explained that the properties and conditions within the product may be of concern to people's health ?

Or is that why you see So many for sale ?


----------



## john87300 (Oct 12, 2011)

Having been brought up with London "smogs", in a house with lead pipes, asbestos all over the place, including the ironing board, with a family who smoked like chimneys, having my feet xrayed in the coop every time I needed new shoes as a kid, having all sorts of now banned chemicals around the house for cleaning and whatever, (like the "Flit" guns mentioned above), and have smoked for 40 years, no way am I going to worry about the unquantified risk of a minute amount of radium in a watch I wear once very couple of weeks. I think I'm in far more danger cutting wood for my fires with a chainsaw everyday, or by being tailgated by French Routiers late for their lunch!


----------



## Roamer Man (May 25, 2011)

Mr Whimpy said:


> Defeats the objective of owning an old timepeace for me
> 
> Hmmm maybe I'm overreacting a little and jumping the gun


You and me both, I'm sure. There may well have been assessments carried out by govt. agencies, and it's only in cases like the one in Scotland that merited action. For the most part the risks must be very small. Besides, we are all exposed to so many toxic contaminants these days, both natural and synthetic, why worry about this one especially?

Years ago I read that the average household contains over 80,000 man-made substances of unknown long-term toxicity. For instance, ever wondered why 1 in 10 kids today suffers from asthma? In my day (those old polluted, bad old days before H&S) it was a very rare condition - prior to 1970 I only ever met two people with it. Now every other person seems to carry an inhaler!

The reason there's so many vintage watches for sale nowadays? Answer: eBay and collectors.


----------



## Roamer Man (May 25, 2011)

john87300 said:


> Having been brought up with London "smogs", in a house with lead pipes, asbestos all over the place, including the ironing board, with a family who smoked like chimneys, having my feet xrayed in the coop every time I needed new shoes as a kid, having all sorts of now banned chemicals around the house for cleaning and whatever, (like the "Flit" guns mentioned above), and have smoked for 40 years, no way am I going to worry about the unquantified risk of a minute amount of radium in a watch I wear once very couple of weeks. I think I'm in far more danger cutting wood for my fires with a chainsaw everyday, or by being tailgated by French Routiers late for their lunch!


Way to go John. I remember as a kid idly picking away at the asbestos on my mother's ironing board, not to mention blowing away the asbestos dust from the ol' Deadwood Morris's brake drums on numerous occassions. How we manged to breath at all is a miracle considering the air pollution. You only have to follow behind a classic car to realise that, the exhaust fumes are enough to make you choke, but not so long ago all cars were like that! However did we survive?


----------



## Mr Whimpy (Jan 14, 2012)

I knew I was overreacting LOL

Your absolutely right car fumes, chemical for cleaning and not to mention asbestos.

And yes your are correct eBay opened the doors for loads of everything for sale

Phew that's better I will keep looking


----------



## William_Wilson (May 21, 2007)

Oh my, let's put the non sequiturs aside for a moment. :wink2:

Aside from large lethal doses of radiation and particles becoming lodged inside the body, the risks are cumulative. The exposure you have from a radium watch is added to every X-Ray you have ever had, along with any other sources you've been near (including natural background radiation). The "lucky" thing about these classic watches (expecially the Ebay ones) is the fact most of them have been opened up numerous times over the years, and the dust from the lume has not accumulated too much. The unlucky thing about them is that the intensity of the radium lume compound used in various watches in the 30's and 40's varied greatly. All I'm suggesting is a few simple precautions. If you can check your radium watches with a Geiger counter to determine the level of radiation thats great, otherwise don't wear them all of the time or spend extended periods in close proximity to your collection. Avoid inhaling or ingesting the lume dust as well. 

Later,

William


----------



## john87300 (Oct 12, 2011)

Can anyone cite a VERIFYABLE case of a watch hobbyist suffering any medical ailment directly assignable to radiation from his/her watches?


----------



## john87300 (Oct 12, 2011)

Can anyone cite a VERIFYABLE case of a watch hobbyist suffering any medical ailment directly assignable to radiation from his/her watches? I think not.

Let me quote, if I may, from Idaho State University:

* "How much is too much radiation?*

That is a very good question and not easy to answer. This will depend on the individual, the risk they are taking and the benefit that they will receive from it. As pointed out in the Radiation and Us page, we receive approximately 360 mrem of radiation every year. The legal limit imposed by the federal government in this country for an occupationally exposed worker is 5,000 mrem per year. If we look first at doses received in a short amount of time, (acute doses), the first biological effect begins to be able to be detected by laboratory analysis at 10,000 to 25,000 mrem. Actual immediate life threatening doses are limited to levels of 100,000 mrem and above. The life shortening doses may be lower than that, and are approximated by taking the data at higher doses where the effects are apparent and extrapolating the risk down to lower doses. Being conservative, the regulators use a model of a straight line from high doses down through the zero dose/zero risk point, so that any dose presents some small risk. Also you need to know that doses received over a longer period of time allows for repair of cells by the body, and presents less of a risk. So to answer the question, the doses receive by the workers in nuclear power, an extra 100 to 5,000 mrem per year (average about 500 mrem), are seen by most scientific organizations as presenting a low risk compared to normal occupational hazards encountered during a working lifetime."

It then goes on to quote that the annual radiation from a pocket watch with a radium dial is 6mrem per annum, whilst a coast to coast plane round trip in the USA attracts an increase of 5mrem.

As a non sequitur: remind me to email my daughter at BA and warn her not to fly anymore!


----------



## gaz64 (May 5, 2009)

john87300 said:


> Can anyone cite a VERIFYABLE case of a watch hobbyist suffering any medical ailment directly assignable to radiation from his/her watches?


 not a watch hobbyist but a tale from the early days

http://en.wikipedia.org/wiki/Radium_Girls


----------



## William_Wilson (May 21, 2007)

It's as if I was suggesting everyone pull a red hot horse shoe from the forge and stick it in their eye. 

Now let's talk about compact fluorescent bulbs. :lol:

Later,

William


----------



## pugster (Nov 22, 2004)

unless you are scraping multiple dials crushing the lume and doin a few lines a day i wouldnt worry about them


----------



## mel (Dec 6, 2006)

I've worn early Luminous watches all my days, and I don't have a problem







Hang on and I'll ask my other head (Zaphod) if he's still good as well :lol: It's all relative, I've probably been exposed to more High Frequency Radio and Electro Magnetic sources than most of you put together - having been in trouble-shooting for the Leccy Board - and I've suffered RF burns from playing silly bludgers and trying short cuts, stuff like that.

Approach all of these things with some kind of Risk Assessment in mid - like you buy a Luminescent dial watch and you can see the bits of paint floating around inside the dial when it arrives from the fuzzy ebay piccie :yes: Opening that up to blow the particles about is NOT a good idea. Approach sensibley and research, ask advice, then decide what you want to do.

MEERKAT EMOTICON Seeemples!


----------



## aroma (Dec 11, 2009)

You know, it's a funny thing - I raised the issue of radium on watch dials a few months ago on a different forum and was rounded on by the military watch nuts who completely dismissed the risks as negligible.

I am a retired Physicist - maybe not a very good one but I do know a bit about radiation. The issue I had was that even taking the back off a radium-dialed watch posed a risk as minute particles of radioactive dust will fall out. OK, it poses a very slight risk but a risk it is nonetheless. Whilst it may do me little harm (I'm probably too old for it to have an effect) I do have grandchildren crawling about on the carpet and putting their fingers in their mouths. I was so concerned about this that I disposed of my WWW watches.

Like some of you, I was brought up when things like asbestos and radium were thought to pose no real danger but I can see the day when watchmakers/repairers will refuse to service a watch with radium lume. Yes it is a shame as the watches have so much history and character - maybe it is time to get your radium dial 'repainted' with something that looks the part but is not hazardous.

OK this is only my opinion - each to their own.


----------



## Roamer Man (May 25, 2011)

aroma said:


> You know, it's a funny thing - I raised the issue of radium on watch dials a few months ago on a different forum and was rounded on by the military watch nuts who completely dismissed the risks as negligible..


I think it might be useful if we knew when the use of radium was finally discontinued. Wiki says it was used up to the late 1960s, but an earlier date is suggested for Roamers which are painted with Pm (Promethium147). The earliest example I know of is 1962. I'm assuming they made the switch because Pm 147 has quite a short half-life (< 20 years). That being so, in my calculation the amount of Pm remaining on a 1960 watch would currently be reduced to about one eigth by now? Don't know which daughter products are produced in the decay of Pm147, but correct me if I'm wrong, isn't there is a significant reduction of risk in this case?

I personally don't have any watches from the 1940s, just one or two from the mid to late 1950s, and my earliest one came with the dial virtually stripped clean already. However, I do have 3 pairs of hands which are suspect, which brings me on to my next questions about lume:-

Radium we know glows continuously, but what about Pm? I/we need to know the difference for easy identification purposes, so..

1) Does Pm need exposure to light to become luminescent, and if so, how persistent is the glow time-wise?

2) When did they stop using Pm?


----------



## William_Wilson (May 21, 2007)

What I've seen of the popular brands, they seem to have stopped using radium at the end of the 50's (civilian models). The Omegas and Rolexes, from the very early 60's, I see on the internet all seem to have tritium dials (half-life 12.6 years).

The energy (rays) emitted by radium/tritium/promethium energises the luminous compounds they are suspended in, that's why they glow. The compounds are similar to the compounds used in Luminova and other brands of lume. The difference being that the non-radioactive lumes use the sun or artificial light to energise them.

Later,

William


----------



## harryblakes7 (Oct 1, 2010)

William_Wilson said:


> It's as if I was suggesting everyone pull a red hot horse shoe from the forge and stick it in their eye.
> 
> Now let's talk about compact fluorescent bulbs. :lol:
> 
> ...


Flourescent bulbs ..... VERY Dangerous, banned in German hospitals, causes DNA alteration, give of Phenol gas ( used to gas people in the holocaust ) contain mecury and will give you a suntan in 30 mins, and they give me a migrane, that's why i hate them!!! :yes:


----------



## AbingtonLad (Sep 8, 2008)

Argh, 'tis all a storm in a teacup! The risks from luminous dials revolve almost exclusively around the ingestion of material. Yes there is a slight external risk from gamma emissions, but radium is primarily an alpha emitter and alpha particles won't say boo to a goose (unless you shove them down the goose's throat). Of course you shouldn't play with radium dials that show flaking of material, in much the same way you shouldn't lick lead paint, comb your hair with razor blades or use asbestos as a snuff substitute.

To put it into proper context, one extensive US survey estimated the risk to your gonads (yes, let's be honest, they are often the closest thing to your wrist) from regularly a wearing watch with a highly radioactive dial to be 60 mrem (millirems) per year - roughly the same as a single hip x-ray. The corresponding increase in your chance of getting cancer is no greater than smoking just 160 cigarettes per year.

The poor radium girls not only ingested radium every minute of every day at work, but they then painted it on their eyelids, nails and lips when they went out because it generated such a lovely glow in the dark. But ingestion was the main problem - radium was deposited in their bones and sat there doing its merry thing, constantly irradiating their very sensitive bone marrow.

My wife is a radiation protection officer and has received training in what to do if a lorry carrying smoke alarms crashes in a built-up area. She has never received training on prying watch lovers away from their pre-60s timepieces. Her limit for radiation exposure in any one year is around 2,000 mrem. That means she could retire and wear 33 radium dialed watches at the same time, without significantly increasing her risk of cancer.

Taking any ultra-cautious stance to its logical conclusion, you should also be concerned about the dentist x-raying your teeth, being a frequent flyer or changing the battery in your smoke alarm. These all present a risk, no matter how small. As does the very act of breathing.

The bottom line is, indeed, you pays your money and takes your choice. Nothing in life is risk free and if you enjoy watches with radium dials then why the heck not stick with them.

Who wants to die of old age anyway? And besides, for most of us the risk we should really be worrying about is the one we aren't aware of. Yet.


----------



## AbingtonLad (Sep 8, 2008)

Incidentally, the 'benefit gained from exposure to radiation' is an interesting one. A fire/smoke alarm may shorten your life very slightly because the device contains radiation, but this risk is far, far outweighed by the reduction in the likelihood of you being killed by fire or smoke. So, in short, install lots of alarms. I know I have.

Just thought I'd better mention that!

K


----------



## gaz64 (May 5, 2009)

So don't snort the dust and lick the dials then?


----------

