Computers put out more radiation than a nuclear reactor!

MrFluffy · May 31, 2001

Disclamer: None of this is intended of scaring anyone, its just some intresting facts that i came accross, giving the ammount of Rimms emited from a PC one would thing cancer is linked to PC, but its really not. To give an example of how this isnt really effecting anything: Ray has basicly spent his life behind a computer 😉 and he has no cancer... so no one is in any real danger...

At school in our Chemistry class, we had an U.S. Navy Nuclear engineer talk to us about, well nuclear energy and radiation. Well the interesting part is in the Navy the current regulation for expose to radiation is 3.5 MilliRimms p/Q. Mostly the engineer gets ~2-3 MR/Q within the reactor room....

One day he was foolishly careless and he scraped his arm. He had to do a desk job until the wound healed, but he kept the thing that measured MRimms w/him. He had to do something on a PC, and he spent 3 hours on the PC. The weird part is that he received 16MR within the 3 hours... more than he received in the reactor....

Which means that (assuming that the figure is constant w/any PC which case isn?t true, but it makes me do less math 😉) in one day (24hours) if the pc was left on the whole day and night the PC would emit 128 MR/Day. Multiply that by the quarter and you get 11.520 Rimms/quater, which in fact is way above the world wide standard for safety of radiation of 3 Rimms a quarter (the U.S. Navy is "safer" using 3.5 milliRimms instead of Rimms, so infact 11.520 Rimms is 11520 MR.. which is 384% over the world wide standard for safety) Multiply that number by 4 and you get 46.08 Rimms/year, in which the world wide standard is 5 Rimms a year... a 921.6% over the standard... so if one sits in front of a PC for um lets say 5 hours for 5 days all year one would get 15.208 Rimms a year 304.6% over the standard safety limit 🙁

NOTE: Rimms is the unit of measure for radiation; it works like grams and milligrams of course the more Rimms you have the worse you have it. 🙁

ViRGE · May 31, 2001

Oh well, I need a third arm, that way I can type faster.😀

gogeeta13 · May 31, 2001

you party pooper:|

MrFluffy · May 31, 2001

yea like im gonna take my facts seriously...
seriously though, its not really true, its all assumtion, i do not know what kind of PC the dude used for typing his report, it prob. was some lowest bidder thing ~486 😉 acctually what i hypothisis is its the mon. which emits the radiation... and newer mon. are more "energy efficant (Sp?)" so assuming so means less power, less radiation.. or so it would seem... oh well its not gonna be a thing that i will worry about i havent heard anything that would make the things acctually danguous.. also the thing that calculates the radiation is sinsitive to ALL radiation.. (if any is actually good..)

RaySun2Be · May 31, 2001

As far as I know I don't have cancer, but that third eye sure comes in handy watching the kids. 😉
You know that saying "he must have eyes in the back of his head...." 😉😉

networkman · May 31, 2001

Chances are his counter was located near the back of an older monitor; the older monitors do give off a "healthy" dose of radiation, but primarily from the back side and not the front where most users are sitting.

AppleTalking · May 31, 2001

Yikes!

Now we'll start hearing excuses like, "I can't leave my computer on 24/7 to run RC5. It gives off too much radiation."

Maybe that's why I have trouble keeping fish alive in my room!! 😀

Nick

JonB · May 31, 2001

OK, Mr. Fluffy, let me say a few words. I am also a former Navy Nuclear Reactor Operator and still work at a commercial nuclear power plant.

First, I have personally used radiation detectors (normally called Geiger counters) to measure the radiation from TV and computer Cathode Ray Tubes. Modern color monitors emit virtually nothing in the front and very small amounts of radiation to the rear. This would be in the range of 1 to 2 millirems PER DAY if you parked your butt in the absolute worst area. In front, where Ray parks his butt, he would potentially receive 1 to 2 millirems PER MONTH. You get 30 to 80 millirems during a commercial plane flight, so put it in perspective.

If the guy who talked to your class was measuring the radiation from an old monochrome monitor, it would have been higher. Also, he may have been using the "least accurate" measurement tool called a Self-Reading Pocket Dosimeter (SRPD) which can jump 10 millirem because you bumped it with your coffee cup. It works on a static charge dissipation and is only used for indication, not for actual radiation dose received.

Also, the allowable dose rates (by Federal Law) for radiation workers is more like 4000 millirem/quarter. I certainly never came close to that in my 28 years in the nuclear business. In fact, if you totalled ALL my radiation dose in 28 years, it only equals 5500 millirem (and I got 2000 of that in one afternoon).

So, bottom line, unless you scrounged up some piece-o-crap monochrome monitor, you aren't getting any radiation worth worrying about. Your microwave oven leaks more than that. Your smoke detectors, too.

ViRGE · Jun 1, 2001

Going OT: 2000 in one afternoon!? What the heck happened JonB?😱

Pretender · Jun 1, 2001

By your post JonB I'm guessing that radiation is measured as more of a cumulative thing (ie. 5000 millirems in a lifetime) rather than a time-based measurement (ie. 100 millirems per day). why? shouldn't it be shed through dead skin or passed out through waste instead of remaining perminantly in the body?

kmmatney · Jun 1, 2001

I work for a company the produces X-ray machines for looking at semiconductor wafers. The Federal government has set a maximum annual radiation exposure limit of 5,000 mrem (5 rem). We usually measure the radiaton in terms of mRem per hour, so the limit is 0.57 mRem/hour.

Its way above that on an airplane! While on an airplane, you are basically exposed to 2-3 times this limit, just from the thin atmosphere (and the Aluminum body of a plane does not stop X-rays very well!).

Here's a tidbit from our safety manual:

"It is estimated that the average individual in the United States receives an annual dose of about 300 mrem (0.3 rem) from all natural sources of radiation. For perspective, a modern chest x-ray results in an approximate dose of 0.008 rem (8 mrem), while a diagnostic hip x-ray results in an approximate dose of 0.083 rem (83 mrem). "

In any case, smoking is much more dangerous than radiation from a computer, or even from radiation on an airplane.

I am not sure why the Navy has a 14 rem annual limit - The limit for X-ray exposure is definately 5 rem per year. I know this - its my job!

One last edit: I've put our radiation meters in front of many monitors in our lab, and I've never observed any monitor to be over the federal limit. This includes integrating the counts for several hours.

kmmatney · Jun 1, 2001

<< why? shouldn't it be shed through dead skin or passed out through waste instead of remaining perminantly in the body? >>

Radiation doesn't "stay" in the body (unless you eat radioactive food). Something like an X-ray will either be completely absorbed by your body, or pass right through. Once absorbed, its energy is gone and the radiation particle no longer exists.

The potential problem is that when the X-ray energy is absorbed, it can cause damage to the cells in the body, possible causing mutation of that cell. If you get hit with a very high does of X-rays at one time (such as 1 whole rem) you'll damage enough cells at once to be in serious trouble. When radiation is taken in small doses over time, it has little cumulative effect over your lifetime.

<< The weird part is that he received 16MR within the 3 hours... more than he received in the reactor.... >>

Again, that monitor must have been a really old one, or contaminated. That amount of radiation is really high. I've measured plenty of monitors (all 10 years old or less) and not measured anything like that. However, I can believe that older monitors may have emitted more radiation.

JonB · Jun 1, 2001

Oops. I got my quarterly and yearly limits mixed up. The book does say 5000 millirem/year (5 rem) and 1250 millirem/quarter. The limits were a little higher years ago, but not much. Most businesses/industries will then set a lower limit of 1000 millirem/quarter or even lower. If you never exceed a quarterly limit, you can't exceed a yearly limit.

Virge, the one time dose was during a reactor coolant pump repair job in the reactor compartment of my ship (USS Truxtun). I wasn't even doing much work, but instead was handling tools near the work site. Since I exceeded a quarterly limit, I was taken off the radiation worker list for the next quarter. Since they knew I was going to exceed the dose limit (along with five others), they filed paperwork and all was cool. By the way, they decided that the overall radiation exposure of the crew would have been much higher if they had to swap us during shift change, so we finished the job.

Pretender, they monitor radiation exposure as "acute" and "chronic." When you get an "acute" dose of radiation, it is a one-time exposure and the quarterly limits apply. There really aren't any legal daily limits, but you aren't supposed to get more than your quarterly limit in any one day. The radiation protection staff keeps track of all your daily doses and can always tell you how much dose you have gotten (daily, quarterly, yearly, or even lifetime).

Acute dose - the concern about one time exposure is that large doses of radiation could cause changes in your blood producing organs and could cause symptoms similar to anemia (low red blood cell count). Radiation has the most affect on cells that reproduce rapidly.

Chronic dose - lots of small exposures over many months and years is considered "chronic." If you developed cancer from radiation exposure, it will most likely be from chronic dose, not acute.

Since the human body is exposed to radiation constantly, it does have cellular repair mechanisms to handle small acute doses without problem. Large chronic dose can slowly overcome some of those defenses, possibly resulting in cancer. Oddly, there are some people who study this stuff who believe that chronic exposure may actually reduce the risk of some cancers. Remember, they use radiation to treat some cancers.

The rule we use is called ALARA. As Low As Reasonably Acheivable

MrFluffy · Jun 1, 2001

Exactly..... JonB, and kmmatney
as i said a little while ago the navy was prob. using a very old computer and mon, plus where he was working, mabe of some other electronical parts were aslo a factor, also he was not using a Geiger counter, he was using the belt thinggy (i cant remember what the thing was called ). He really neve specified, i was just going off what he said...
which of cours i was assuming was wrong, but it made for some intresting numbers, howerver unlikely any of us are acctually exposed to those ammounts by the mon. or the PC.

IJump · Jun 1, 2001

I figure I am going to die somedway anyway, why not death by computer radiation while reading posts about radiation on the computer? 🙂

JonB · Jun 1, 2001

That's the spirit, IJump. Now, lean in a little closer and let the stray X-Rays do their worst. Go ahead, hug your monitor. hmmmm, doesn't that feel good? Kind of warms you from the inside out.

ps, Mr. Fluffy. The belt device your Navy engineer was wearing is called a TLD or Thermoluminescent Detector. It is actually a small crystal, wrapped in wire. When a gamma / x-ray hits an atom of the crystal, that atom goes to an "excited" state, meaning an electron jumps out to the next shell and stays there. At the end of the day or week or month, when it is time to see how much radiation exposure a person got, the TLD is put into a device that runs electricity through the wire and heats the crystal (just like a toaster oven). When the crystal gets hot, all of the excited atoms return to their unexcited state. In the process, they give off a photon (light) which is measured by super-sensitive light meters. The amount of light is proportional to the amount of radiation. It is very, very accurate and predictable, plus has a accurate measuring range from 2 millirem up to 1000 REM (that would be 1,000,000 millirem). Since you wear the TLD on the largest part of your body (mine at least), the dose received at your belt-line is considered to be your "whole body dose."

IJump · Jun 1, 2001

I feel warm and fuzzy all over. Kind of like standing in front of that big satellite dish. mmmmmm goooood. 🙂

Poof · Jun 1, 2001

I did a project some time ago with radioactively-tagged antibiotics in order to trace antibiotics that might be present in milk - all part of a test kit. With the small dose that those tags gave off, the average background radiation was often enough to skew results...

Also as a note from the chemistry perspective - there are different types of radiation that you get exposed to, with Xrays being one part of the EM spectrum. Microwaves are another more common form - and just as your food cooks in a microwave oven, so to can you if exposed to them at the level and frequency of a microwave oven (which is partly why you hear many people questioning the current wireless technology - which is in the 2.4GHz band with the ovens - although obviously NOT at the intensity of the oven).

Most radiation passes through your body harmlessly, but there are types - specifically those that create beta radiation, that can cause the sub-dermal damage.

MrFluffy - revel in the fact that being in school right now allows you access to wonderful sources like the web, that wasn't available when I was in school. 🙂

For some interesting info, see this site. 🙂

MrFluffy · Jun 1, 2001