None
http://camerapedia.wikia.com/wiki/Radioactive_lenses
You get more radiation from a transatlantic flight than sleeping with a Minolta strapped to your face
1st grade physics - as alpha particles have trouble piercing paper and are the particles emitted by the compounds used in doping the glass listed above, I'm still alive and I've got a 58 PG MC Rokkor 1.2 - only grew a 3rd arm after a long weekends use. An eyepiece with radioactivity would be a worry but a lens has such a tiny microroentgen dose that there's nothing to worry about.
I'm praying for you to be justified :) but there are different opinions:
"Assuming (based on the reading) that looking through the viewfinder is very roughly an order of magnitude greater exposure than the general usage, looking through the viewfinder for an hour is about 1µSv — equivalent to getting an arm x-ray."
6 hour a day usage (that's 6 hours a day with the camera at your face - that's a lot lol) is equal to 3 cross USA flights - not a lot, be a nightmare if you were an air stewardess who liked to take pics ;p
I use a monitor anyway and as the dose tapers off exponentially I reckon my 3rd arm will shrink soon enough :)
Definately something you should be concerned about.
No radiation is good for you and it is accumulative.
If you have a radioactive lens, most important is to store it well. Put it in a lead or steel box. Keep it at least 3 meters from you and others.
Use it occasionally.
You may not have 3 arms but Cancer takes 5 to 20 years to develop...
Actually, I have done much research on the topic. I own many radioactive lenses, which of course is the topic the Op is concerned with.
Of course there is background radiation. And a airline flight will also add to exposure.
But saying these things does not discount additional radiation exposure from a lens.
Two wrongs don't make a right. Be carefull. Be aware.
You wear a watch with glowy numerals? - best take it off, don't stand near your fridge, swim in the sea, etc etc ... London smog, riding a bike to work , microwave towers, stress, beer, sitting in studios for 9 months a year, living in front of a computer monitor, eating burgers, crossing the road, using a mobile phone ... supporting Liverpool - all bad for your health or potentially lethal, I try not to worry.
Stop worrying about lenses.. And start worrying about food..
I don't know about lens radiation, but a trip from Boston to California via airplane is equal to one chest xray...a head CT scan is equal to 300 chest xrays...these things will eventually increase your chances of developing cancers.
I moved to Japan March 22nd of 2011, so for me learning as much as possible about radiation before coming was very important. Granted much of it has left my brain now (the knowledge not the radiation), but there are three main factors, accumulation and more importantly type of radiation, and being in the air rather than sealed in an object can also make a difference. I do npt know enough about thorium at the moment to say whether the lenses are safe or not, but with the transatlantic flight comparison I cringe, as this comparison was used by fake experts the world over after the fukushima incident. Needful to say, it is completely different. Different type of radiation, and very different delivery. Like with an Xray, the radiation from an airline flight is not being directly ingested or inhaled. With Fukushima the radiation went everywhere, the water, food, and air supply (read up on a little something called plutonium oxide which was abundant in the explosions). Anyways, when radiation is ingested or inhaled it is there forever. Allot of people don't really know how radiation gives you cancer, so let me lay out what I know. Every now and then the nucleus of your cell is hit by a radioactive particle, whether it be natural background radiation, or the others. Usually the cell dies, and no harm is done to you other than the loss of a nice little cell. However sometimes the cells nucleus is hit, but it lives. This is what can lead to a mutated cell formation, and if the cell is strong enough to survive separation, it continues to create mutated cells till what we know as cancer is created. The thing is all kinds of radiation have the potential to cause cancer, it is just a matter of delivery. Some radiation indeed has trouble penetrating paper, however usually these types of radiation have no trouble penetrating exposed cells, and this kinda of radiation usually has the longest half life. So when these radiations are inhaled or ingested, they are there for good, and often have a half life much longer than our own life. Plutonium is one of the most deadly with an extremely long half life. Cesium on the other hand has a short half life, but is quite capable of penetrating skin, and also accumulates in very very high levels in cows milk, so though it is not with us for long it can do allot of damage in the short term.
Alright if anyone is still reading, there is much more info online if you dig deeper than the BS from the pro nuclear industry which will pop up first and second and third and...... so on..
@mee: Not entirely true.. There is so much more information, that you didn't include.
4 most important ionizing radiation sources for man:
Alpha particle: a helium nucleus without the electrons, can't break skin. Can be inhaled. The energies are usually low enough that simply handling these isotopes with tweezers or forceps puts your hand far enough away that it won't burn you.
Beta particle: an electron or positron, can damage DNA but usually not more than skin deep. Can be inhaled. These are more serious and generally need some shielding, like aluminum foil or storage in a metal can.
Xray: a photon, can penetrate deeply and damage DNA depending on energy and frequency. CANNOT be inhaled. Xrays are sourced from the electrons of an atom.
Gamma: a photon, can travel right through you and damage DNA depending on energy and frequency. CANNOT be inhaled. Different from Xrays as these are sourced from the nucleus of the atom.
Also, you have some misconceptions about some of the isotopes, probably because of the media frenzy around the relatively few accidents that have happened and, of course, all of the spin the media puts on these sorts of things to sell news..
Plutonium is primarily an Alpha emitter and is relatively safe to handle in most of it's isotopes, although purified weapons plutonium can become critical and start to emit Gamma rays and Neutrons, which then becomes extremely dangerous if you don't control the criticality. That's not going to happen and you aren't going to get irradiated or ingest/breath plutonium because it's rarely used in anything but bombs and spaceships, so why are you using it as an example to scare people?
And yes, I believe in nuclear power, and not just because it has the best safety record of any power source. I do think that we need to move beyond the 50 year old designs that are still in service though.
Cheap and reliable Thorium breeder reactors are the future.
Maybe if your lenses come from the kodak factory it could have some nuclear traces :) http://www.democratandchronicle.com/article/20120511/NEWS01/305120021/Kodak-Park-nuclear-reactor?odyssey=nav|head
I used Plutonium as an example because it is a little known fact of the Fukushima disaster. More than 150,000 so called spent rods were stores on top of the reactors in pools of water. When the reactors exploded these rods flew out for miles many landing in the ocean, but also many on land. The very real problem here is that the spent rods which began melting and are still melting to date contain high levels of plutonium oxide. Plutonium oxide, unlike the heavier solid plutonium which was covered by the "media frenzy" is a gas, and can spread easily through the air. IE when the media said "don't worry because plutonium is too heavy to travel to the US, or even to Tokyo" this was BS, because it's gas form is quite different.
@svart, as I mentioned stuff has fallen out of my brain since my cram session. I cannot remember the in depth details, but I remember enough to do my best to protect myself. I am not trying to scare, simply educate beyond what the mainstream media covered. There was a definite cover up about how much hit the US, and even a larger cover up about how much hit tokyo, and the rest of Japan. Kyoto actually had slightly higher levels than Tokyo last time I visited, some say from the typhoon that hit just before, and some say it's from a near bye reactor. I really could go on and on about the blatant cover ups from the IAEA (nuclear industry spokes people, not protection agency) but this is not really the place, I just was trying to make the distinction between different types of emitters, which you did better than I. However I am definitely not onboard with the non existent future of Nuclear energy. There is no need. With all but 1 reactor shut down in Japan, the lights are still on and the high tech computer shops are still running all their gizmos. In a country that loves electricity, and had a huge ratio of nuclear before the accident, I think this speaks strongly to the misconception that we need nuclear. It's goverment subsidies that keep most of it going. Much like the whaling industry in Japan. Anyways, Rant complete. If you want to talk more PM me svart, or anyone for that matter.
With all but 1 reactor shut down in Japan, the lights are still on and the high tech computer shops are still running all their gizmos.
You are very far from reality, as Japan is having big problems because of populistic measures.
Impact on productive sector is big.
It is also interesting that it is exactly same motherfuckers who lead middle class expermination are biggest proponents on nuclear energy ban. Fun, isn't it?
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