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Archive 2010Beware Radioactive Lenses
p.1 #1Beware Radioactive Lenses
It has come to my attention that many older lenses are radioactive. Be careful. The ones that get the most "ink" for this are the old Canon FD and Pentax m42 lenses, esp. 35/2 and normal lenses. I have read quite a bit and it seems you cannot tell whether or not a lens is radioactive without actually testing it. Some 50 1.4 Fd can be quite active, some not at all. The annual average dose in the US is usually about 300 millirems/year. Lenses can emit one millirem/hour or more, although it would be localized and not reach the entire body. Also some lenses are more active than others, and if you had a particularly active sample, which granted is probably in the vast minority, it might be wise to use a different lens.
If you choose to use these lenses, you might try to keep some distance. The amount of radiation seems to fall off rapidly, even at the back of the camera. Store them in a different room from where you sleep, though remember gamma radiation travels through walls so putting them in a different room on the other side of the wall from your bed won't do much good.
Personally I'm probably going to try to avoid radioactive lenses.
http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?bibcode=1988JBAA...98..309F&db_key=AST&page_ind=1&plate_select=NO&data_type=GIF&type=SCREEN_GIF&classic=YES
http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1717/nureg-1717.pdf
If you choose to use these lenses, you might try to keep some distance. The amount of radiation seems to fall off rapidly, even at the back of the camera. Store them in a different room from where you sleep, though remember gamma radiation travels through walls so putting them in a different room on the other side of the wall from your bed won't do much good.
Personally I'm probably going to try to avoid radioactive lenses.
http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?bibcode=1988JBAA...98..309F&db_key=AST&page_ind=1&plate_select=NO&data_type=GIF&type=SCREEN_GIF&classic=YES
http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1717/nureg-1717.pdf
Dec 17, 2010 at 12:39 PM
p.1 #3Beware Radioactive Lenses
Phew, time to toss that 1974 Super-Takumar 50 1.4 I've been using as a slide loupe!
Dec 17, 2010 at 12:55 PM
p.1 #4Beware Radioactive Lenses
What about all those ten thousends of people that used them every days for many years. And had them in the same room they where sleeping every day also. Never heard about anybody that got sick........
Dec 17, 2010 at 12:59 PM
p.1 #5Beware Radioactive Lenses
Just to put this in perspective...
(Quoted from a Mr. John Ratliff, from another forum):
"I took the lens on my Canon F-1N, with a power winder and an AE Finder FN mounted on it the body. I met with a representative of ThermoFisher, who makes the Mini900 GM counter that I use. I wanted to show him the ionizing radiation source that I was using in the training. In the process, I was able to get measurements of the radiation at the eye cup of the AE Finder FN with the 35mm F-2.0 lens. Here are the measurements from today:
--At 1/4 inch off the lens focus ring, 1-2 uSv/hr, settling to about 1.5 uSv/hr over...Show more →
Then later...
"According to a quick Google search, the radioactive elements in cigarette smoke are:
--Polonium-210 (Po-210)
--Lead-210 (Pb-210)
--Radium-226 (Rd-226)
Radium-226 decays into radon, and Po-210 and Pb-210 are "long-lived decay products of radon. Sticky hairlike structures on both sides of tobacco leaves collect these from the atmosphere. Tabacco roots also absorb some radioactivity from the soil." K.S. Parthasarathy, Secretary, AERB, source: http://www.hindu.com/thehindu/seta/2003/06/05/stories/2003060500020200.htm
According to this internet source, Carol W. LaGrasse, P.E., member Adirondack Branch Advisory Council of the American Lung Association of N.Y. State, 1986, "For a person smoking 1 1/2 packs of cigarettes a day, the annual radiation dose to the surface of bronchial cells...Show more →
(Quoted from a Mr. John Ratliff, from another forum):
"I took the lens on my Canon F-1N, with a power winder and an AE Finder FN mounted on it the body. I met with a representative of ThermoFisher, who makes the Mini900 GM counter that I use. I wanted to show him the ionizing radiation source that I was using in the training. In the process, I was able to get measurements of the radiation at the eye cup of the AE Finder FN with the 35mm F-2.0 lens. Here are the measurements from today:
--At 1/4 inch off the lens focus ring, 1-2 uSv/hr, settling to about 1.5 uSv/hr over...Show more →
Then later...
"According to a quick Google search, the radioactive elements in cigarette smoke are:
--Polonium-210 (Po-210)
--Lead-210 (Pb-210)
--Radium-226 (Rd-226)
Radium-226 decays into radon, and Po-210 and Pb-210 are "long-lived decay products of radon. Sticky hairlike structures on both sides of tobacco leaves collect these from the atmosphere. Tabacco roots also absorb some radioactivity from the soil." K.S. Parthasarathy, Secretary, AERB, source: http://www.hindu.com/thehindu/seta/2003/06/05/stories/2003060500020200.htm
According to this internet source, Carol W. LaGrasse, P.E., member Adirondack Branch Advisory Council of the American Lung Association of N.Y. State, 1986, "For a person smoking 1 1/2 packs of cigarettes a day, the annual radiation dose to the surface of bronchial cells...Show more →
Dec 17, 2010 at 01:04 PM
p.1 #6Beware Radioactive Lenses
Lars Johnsson wrote:
What about all those ten thousends of people that used them every days for many years. And had them in the same room they where sleeping every day also. Never heard about anybody that got sick........
None the less, you use past tense about them... It could, of course, be a consequence of Life itself, with a death rate of 100%.
What about all those ten thousends of people that used them every days for many years. And had them in the same room they where sleeping every day also. Never heard about anybody that got sick........
None the less, you use past tense about them... It could, of course, be a consequence of Life itself, with a death rate of 100%.
Dec 17, 2010 at 01:13 PM
p.1 #7Beware Radioactive Lenses
Thanks for the heads up Mike, but this has been discussed quite thoroughly before in this forum (and in many others). I personally won't buy lenses that I know to be radioactive just because I avoid some extra exposure/ionizations. Just out of principle. It's a very small price to pay for me (not being able to buy some good lenses which have radioactive glass dopants).
All-in all the health risk from radioactive lenses is quite minute -- there are far more harmful sources of radiation (and toxins) around, like cigarette smoke (see above).
@Lars: Thoriated glass emits mostly alpha radiation, which hardly travels through air (a few cm), so the risk of inhaling it from a lens that is in your room is probably not very real. Some of the nuclear decay products of thorium do emit beta and gamma radiation too though, which can be measured at the eyecup of the camera when the lens is mounted.
Edited on Dec 17, 2010 at 01:32 PM · View previous versions
All-in all the health risk from radioactive lenses is quite minute -- there are far more harmful sources of radiation (and toxins) around, like cigarette smoke (see above).
@Lars: Thoriated glass emits mostly alpha radiation, which hardly travels through air (a few cm), so the risk of inhaling it from a lens that is in your room is probably not very real. Some of the nuclear decay products of thorium do emit beta and gamma radiation too though, which can be measured at the eyecup of the camera when the lens is mounted.
Edited on Dec 17, 2010 at 01:32 PM · View previous versions
Dec 17, 2010 at 01:19 PM
p.1 #8Beware Radioactive Lenses
Taking this info...
--At 1/4 inch off the lens focus ring, 1-2 uSv/hr, settling to about 1.5 uSv/hr over time (as reported above). --At the eye cup, where the eye would be, 1 uSv/hr (it settled there, and varief from about 0.6 to somewhat over 1.0 uSv/hr).
...let's do some math.
Average (global) human dose per year is approximately 300 mrem.
Total radiation absorbed from focusing and/or holding the lens attached to a camera ≈ 2 uSv/hr.
2 uSv = 0.2 mrem
So, that's ≈ 0.2 mrem/hr.
300 mrem / 0.2 mrem/hr. = 1500 hrs. of exposure
So, if you used the lens attached to your camera for a total of 4.109 hrs. a day, every day, for a year, you would add another 300 mrem to the global average 300 mrem, to get 600mrem.
If you wear a pacemaker, you are getting another 100 mrem...
...If you live in certain parts of the world, like certain villages in India and Brazil that have high levels of thorium in local sands, the dose rate can be much higher. Kerala, India and Minas Garais, Brazil has rates of around 1,000 mrem a year (and this is for terrestrial radiation alone)...
...The actual average total dose rate for the USA is 360 mrem a year. It has been estimated that your chance of dying from cancer increases 10% if you accumulate a total of 250,000 mrem. This would be over, for example. These estimates presumably assume a linear risk factor between dose and the chance of getting cancer, and there are those who now dispute such assumptions, which means the risks from low levels of radiation may be overstated....Show more →
-source http://www.blackcatsystems.com/GM/safe_radiation.html
Is anyone still paranoid about this?
--At 1/4 inch off the lens focus ring, 1-2 uSv/hr, settling to about 1.5 uSv/hr over time (as reported above). --At the eye cup, where the eye would be, 1 uSv/hr (it settled there, and varief from about 0.6 to somewhat over 1.0 uSv/hr).
...let's do some math.
Average (global) human dose per year is approximately 300 mrem.
Total radiation absorbed from focusing and/or holding the lens attached to a camera ≈ 2 uSv/hr.
2 uSv = 0.2 mrem
So, that's ≈ 0.2 mrem/hr.
300 mrem / 0.2 mrem/hr. = 1500 hrs. of exposure
So, if you used the lens attached to your camera for a total of 4.109 hrs. a day, every day, for a year, you would add another 300 mrem to the global average 300 mrem, to get 600mrem.
If you wear a pacemaker, you are getting another 100 mrem...
...If you live in certain parts of the world, like certain villages in India and Brazil that have high levels of thorium in local sands, the dose rate can be much higher. Kerala, India and Minas Garais, Brazil has rates of around 1,000 mrem a year (and this is for terrestrial radiation alone)...
...The actual average total dose rate for the USA is 360 mrem a year. It has been estimated that your chance of dying from cancer increases 10% if you accumulate a total of 250,000 mrem. This would be over, for example. These estimates presumably assume a linear risk factor between dose and the chance of getting cancer, and there are those who now dispute such assumptions, which means the risks from low levels of radiation may be overstated....Show more →
-source http://www.blackcatsystems.com/GM/safe_radiation.html
Is anyone still paranoid about this?
Dec 17, 2010 at 01:26 PM
p.1 #9Beware Radioactive Lenses
AmbientMike wrote:
Personally I'm probably going to try to avoid radioactive lenses.
Ok
Personally I'm probably going to try to avoid radioactive lenses.
Ok
Dec 17, 2010 at 01:38 PM
p.1 #10Beware Radioactive Lenses
Z250SA wrote:
None the less, you use past tense about them... It could, of course, be a consequence of Life itself, with a death rate of 100%.
Indeed. Life is a process of dying. The point is, the radioactivity of these lenses under normal usage has such a minimal effect on your total yearly radiation that it is entirely pointless to worry about it.
In fact, the stress of worrying will do you far more harm than the lens itself, so if you do use them, make sure you don't even think twice about it. If you know you will worry about them, then don't use them. That is a much bigger risk.
On the other hand, don't be a moron and smash the lenses with a sledge hammer in your back yard where your children and pets play.
http://web.aanet.com.au/bayling/repair.html
Will he or his kin be awarded a Darwin award? Possibly.
Edited on Dec 17, 2010 at 01:53 PM · View previous versions
None the less, you use past tense about them... It could, of course, be a consequence of Life itself, with a death rate of 100%.
Indeed. Life is a process of dying. The point is, the radioactivity of these lenses under normal usage has such a minimal effect on your total yearly radiation that it is entirely pointless to worry about it.
In fact, the stress of worrying will do you far more harm than the lens itself, so if you do use them, make sure you don't even think twice about it. If you know you will worry about them, then don't use them. That is a much bigger risk.
On the other hand, don't be a moron and smash the lenses with a sledge hammer in your back yard where your children and pets play.
http://web.aanet.com.au/bayling/repair.html
Will he or his kin be awarded a Darwin award? Possibly.
Edited on Dec 17, 2010 at 01:53 PM · View previous versions
Dec 17, 2010 at 01:41 PM
p.1 #11Beware Radioactive Lenses
cogitech wrote:
Is anyone still paranoid about this?
Hopefully not.
People without fundamental knowledge about physics tend to think that anything radioactive is dangerous. Actually, small doses of it could reduce the risk of cancer.
Just use the bloody glass. Or send it to me.
Is anyone still paranoid about this?
Hopefully not.
People without fundamental knowledge about physics tend to think that anything radioactive is dangerous. Actually, small doses of it could reduce the risk of cancer. Just use the bloody glass. Or send it to me.
Dec 17, 2010 at 01:43 PM
p.1 #12Beware Radioactive Lenses
Lars Johnsson wrote:
What about all those ten thousends of people that used them every days for many years. And had them in the same room they where sleeping every day also. Never heard about anybody that got sick........
There may have been plenty who got sick but they could have all died of cancer by now due to the exposure to radiation but doctors would be totally unaware of the issue and put their deaths down to other causes, such as smoking.
What about all those ten thousends of people that used them every days for many years. And had them in the same room they where sleeping every day also. Never heard about anybody that got sick........
There may have been plenty who got sick but they could have all died of cancer by now due to the exposure to radiation but doctors would be totally unaware of the issue and put their deaths down to other causes, such as smoking.
Dec 17, 2010 at 01:44 PM
p.1 #13Beware Radioactive Lenses
I work in a lab with radio-labeled nucleotides... I'm a lot more worried about getting dosed at work then with a lens I shoot for a few hours here and there (and really, the exposure is even less if you consider the actual time spent with the lens/camera near your face)... if you're this paranoid about irradiation then don't use cellphones (especially not those bluetooth headsets)... and limit your time around any electronics or radio sources... so basically go live in a cave
Dec 17, 2010 at 01:46 PM
p.1 #14Beware Radioactive Lenses
Alf Beharie wrote:
There may have been plenty who got sick but they could have all died of cancer by now due to the exposure to radiation but doctors would be totally unaware of the issue and put their deaths down to other causes, such as smoking.
Of course, but it doesn't make sense when looking up the facts. Aircraft pilots that routinely fly at 30,000 feet do get cancer more often than others, but that dose is thousands of times higher over time than you would get from a radioactive lens, even if you use it a lot.
There may have been plenty who got sick but they could have all died of cancer by now due to the exposure to radiation but doctors would be totally unaware of the issue and put their deaths down to other causes, such as smoking.
Of course, but it doesn't make sense when looking up the facts. Aircraft pilots that routinely fly at 30,000 feet do get cancer more often than others, but that dose is thousands of times higher over time than you would get from a radioactive lens, even if you use it a lot.
Dec 17, 2010 at 01:48 PM
p.1 #15Beware Radioactive Lenses
Alf Beharie wrote:
....and put their deaths down to other causes, such as smoking.
Which is exponentially more likely.
Smoking 1.5 packs per day - 1 year dose: 16,000 mrem
....and put their deaths down to other causes, such as smoking.
Which is exponentially more likely.
Smoking 1.5 packs per day - 1 year dose: 16,000 mrem
Dec 17, 2010 at 01:51 PM
p.1 #16Beware Radioactive Lenses
if you got cancer from a lens then your were either grinding it up and snorting the dust (in which case I think you could get cancer just from silicate dust as a lung irritant) or you had a sever genetic defect in which case you would have gotten spontaneous cancers even if you lived in a lead lined bunker (remember a lot of cancer arises from DNA damage and there is a natural mutation/error rate that is inherent to DNA replication)... so this is pretty much a non-issue biologically... now from the point of view of public perception that a different story (plus in sufficient quantities these can be an environmental hazard when they are being disposed of at the end of their life).
Alf Beharie wrote:
There may have been plenty who got sick but they could have all died of cancer by now due to the exposure to radiation but doctors would be totally unaware of the issue and put their deaths down to other causes, such as smoking.
Alf Beharie wrote:
Lars Johnsson wrote
What about all those ten thousends of people that used them every days for many years. And had them in the same room they where sleeping every day also. Never heard about anybody that got sick........Dec 17, 2010 at 01:52 PM
p.1 #17Beware Radioactive Lenses
Alf Beharie wrote:
There may have been plenty who got sick but they could have all died of cancer by now due to the exposure to radiation but doctors would be totally unaware of the issue and put their deaths down to other causes, such as smoking.
Why would the doctors put down their deaths because of their smoking if they didn't know ? if they died of radiaton....
Lars Johnsson wrote
What about all those ten thousends of people that used them every days for many years. And had them in the same room they where sleeping every day also. Never heard about anybody that got sick........Why would the doctors put down their deaths because of their smoking if they didn't know ? if they died of radiaton....
Dec 17, 2010 at 01:53 PM
p.1 #18Beware Radioactive Lenses
cogitech wrote:
Smoking 1.5 packs per day - 1 year dose: 16,000 mrem
Not to mention the soot accumulating in your lungs (and distributed to the rest of the body), which is probably hundreds of times worse than the radioactive stuff.
Smoking 1.5 packs per day - 1 year dose: 16,000 mrem
Not to mention the soot accumulating in your lungs (and distributed to the rest of the body), which is probably hundreds of times worse than the radioactive stuff.
Dec 17, 2010 at 01:55 PM
p.1 #19Beware Radioactive Lenses
as far as smoking goes the radiation is just a small part of the hit.. there are carcinogenic compounds in smoke that are way worst then the radioactive elements that you're also getting... not smoking and eating healthy (organic for those of us in the US) is way more important for avoiding cancer then your choice of photographic lenses
Makten wrote:
Not to mention the soot accumulating in your lungs (and distributed to the rest of the body), which is probably hundreds of times worse than the radioactive stuff.
Makten wrote:
cogitech wrote
Smoking 1.5 packs per day - 1 year dose: 16,000 mremDec 17, 2010 at 01:59 PM
p.1 #20Beware Radioactive Lenses
morpheus2891 wrote:
if you got cancer from a lens then your were either grinding it up and snorting the dust (in which case I think you could get cancer just from silicate dust as a lung irritant) or you had a sever genetic defect in which case you would have gotten spontaneous cancers even if you lived in a lead lined bunker (remember a lot of cancer arises from DNA damage and there is a natural mutation/error rate that is inherent to DNA replication)... so this is pretty much a non-issue biologically... now from the point of view of public perception that...Show more →
I would hazard a guess that if one is grinding up radioactive lenses and snorting the dust, then they almost certainly do have some sort of genetic defect (to cause them to do such a thing). The world is obviously a better place without them, so why discourage this activity?
if you got cancer from a lens then your were either grinding it up and snorting the dust (in which case I think you could get cancer just from silicate dust as a lung irritant) or you had a sever genetic defect in which case you would have gotten spontaneous cancers even if you lived in a lead lined bunker (remember a lot of cancer arises from DNA damage and there is a natural mutation/error rate that is inherent to DNA replication)... so this is pretty much a non-issue biologically... now from the point of view of public perception that...Show more →
I would hazard a guess that if one is grinding up radioactive lenses and snorting the dust, then they almost certainly do have some sort of genetic defect (to cause them to do such a thing). The world is obviously a better place without them, so why discourage this activity?
Dec 17, 2010 at 01:59 PM