1 September 2009
How Much Radiation Does it Take to Kill You?
Posted by Dan Satterfield
It’s an interesting question isn’t it? Something you should probably know. A little bit if information that you HOPE you never NEED to know. As my sister once said, “Once you’ve seen one nuclear war, you’ve seen’em all!”
In general people are afraid of radiation, and that is a good thing. It can be dangerous. It can also kill off a cancer that is eating you up. It can, and in many places, does keep you warm on a cold winter day. Electricity is dangerous too, but we usually don’t hesitate to change the batteries in our flashlight!
First of all a question. Will you will get a higher dose of radiation living next door to a big power plant that burns coal, or next to a nuclear power plant? The answer of course is you will get more radiation from the plant burning coal.
Radiation measurements can get complicated, but a simplified and generally correct summary is this.
Radiation is measured in Seiverts. That’s the new term. The old unit is called REM. REM stands for Roentgen Equivalent for Man.
100 REM = One Sievert
Most of the time we are measuring radiation in thousandths of a REM. Called milli-rems. If you live on the East coast of the USA, you get about 50-60 milli-rems of radiation a year from natural sources. Some of it comes from radioactive material naturally in your body.
If you live in Denver, built on top of granite and a mile a high, you get about 150 milli-rems a year. You get more if you are an airline pilot and spend a lot of time at 35,000 feet. You also get about 40 milli-rems every time you get a whole mouth x-ray of your teeth. (I should be positively glowing in the dark by now!)
There are three types of radiation. Alpha Rays, Beta Rays and Gamma Rays. Alpha and Beta rays are easily stopped by paper, clothes and skin. Gamma Rays are the bad ones. It takes a few inches of lead or a few feet of concrete and dirt to slow or stop them. A detonating nuclear device will produce a LOT of gamma rays. Even if the blast doesn’t get you, the dose of radiation could be very high, and perhaps fatal.
A dirty bomb is not a nuclear explosion. It’s just taking some radioactive material and blowing it up with conventional explosives. It will not go far and it will spread highly concentrated material over a wide area, and thus greatly reduce the radiation.
I worry very little about a dirty bomb and you shouldn’t either. If you don’t get hurt by the explosion, you are unlikely to be hurt by the radiation. (Unfortunately it appears the terrorists know this now, and it’s even more unlikely you will have to worry about it.)
Cancer cells are very susceptible to radiation. More so than healthy cells, and that is why many cancer patients are given enough radiation to make them sick. Because of this, most people know the symptoms of radiation sickness. Nausea, fatigue, and loss of hair.
How much does it take to get sick? Usually more than 25 rems. That’s 2,5000 milli-rems. A lot more than the 40 millirems you get at the dentist.
LD50
If 100 people get a sudden dose of 350 rems of radiation, about 3.5 sieverts, then about half of them will die in 60 days. 350 rems is considered LD50/60. It means what you think. 50% death rate in 60 days. There is some disagreement about this, some say 3 Sieverts, and it depends on your whole body getting that much. If you get 1000 rems of radiation, you will be dead in about an hour.
If you are unlucky enough to get dosed with 500 rems, you may vomit right away, but the next day you will probably be ok. Experts call this the walking dead phase. You will most certainly not survive beyond two weeks, or so I am told.
Interestingly, if you go to the EPA web sites or local Emergency management sites, you will not easily find this information. Plenty of information on radiation, and the like, but nothing about how much it takes to kill you!
One last thing. How much radiation to absolutely, positively give you cancer? Answer: Probably around 20 Sieverts.
Notice anything?
5 Sieverts will kill you!
This is where the Linear Hypothesis comes in. If 20 Sieverts gives 100% of those exposed cancer, will 1/100th as much (20 rems) give 1% cancer. Seems that way.
The latest Science from the National Academies is that 100 milli-rems per year over a lifetime will cause one cancer in every 175 people. Since about 20% of the population dies of cancer anyhow, the risk goes to 20.05%.
Suppose someone sets off a dirty bomb and it will give me 100 milli rems a year if I stay in the house I love. My risk of cancer will go up by 1/2 of one percent. I’d take that risk. You think the government would let me?
Doubt it.
Congrats, you now know more about radiation than 95% of the population.
Dan
Sources:
http://www.epa.gov/rpdweb00/rert/radfacts.html
Dr. Robert Muller Lecture on Radiation U. Cal. Berkeley and PHYSICS FOR FUTURE PRESIDENTS also by him-on amazon btw
http://www.beyondweird.com/survival/1hrrads.html
National Academies of Science, Prepublication Copy, Health Risks from Exposure to Low Levels of Ionizing Radiation BEIR VII Phase 2, June 29, 2005 page 500 Table 12-9.
Thanks for the article – a fascinating read.
However, the constant switching between Sieverts rems and millirems had me very confused I have to admit.
Prob I need another coffee!
*********
From Dan:
Good point Tom. I found the same when I was researching the post.
Sieverts is now the official measurement for radiation, but one Sievert is a HUGE amount of radiation. So REMS (100 REMS= 1 Sievert) are still used. In daily life though a REM itself is a large dose of radiation. I was at the dentist today and had 7 x-rays. (My mouth has been listed at a superfund clean up site) I took in about 40 millirems. 40/1000 of one Rem!
Then there is RADS, which MOST of the time is the same as a REM. But not always! I decided to try and keep it to the important info that really mattered to all except those who have the words Nuclear Physicist on their office door!
How would one irradiate another with a wall separating them, as in a covert operation? There is a case, I’m investigating as an environmental health & science journalist.
*********************************
Dan comment: Geting hold of radioactive material that dangerous is not easy (or legal in most cases). Gamma ray will pass easily through a normally constructed wall.
Thanks for the article. Have a few questions on top of my head.
1) Can radioactive be ‘infectious’? I mean, after a nuclear blast, can buildings/land around the blast be radiated and emit radioactive of their own?
2) What is the meaning of ‘radioactive dust/cloud’?
thanks.
From Dan:
It’s a common misconception that radioactivity is contagious. It’s not. Someone who has received a high dose of radiation is not giving off radiation. There are some medical procedures that leave a person very slightly radioactive, but they would not normally be dangerous.
A nuclear detonation will throw a large cloud of fine grained radioactive dust into the atmosphere. This dust will fall out downwind over several weeks. The half life of most of these particles is on the order of days, so in a few weeks it would be safe to spend time near it. The threat remains though for a considerable period of time. You would want to wash this dust off ASAP, and avoid inhaling it. See this graph: http://en.wikipedia.org/wiki/File:Relativedoseratesnormalisedforday10000.png
Longer term worldwide fall out can be a much greater threat if there were a nuclear exchange and could end human life on the planet. We are the first species to evolve on Earth with the capability of destroying itself.
actually, during a nuclear fission reaction (that which happens in a nuclear explosion) a burst of neutrons are emitted. These neutrons can then be absorbed into an atom making it radioactive. This is a process known as neutron activation. In a nuclear reactor, the steel housing will become radioactive over time and must be disposed of carefully after decommissioning.
I was a scientist (not this topic) but I’m constantly amazed at how much people don’t know about basic physics. I bought one of the first microwave ovens in 1974, and some people hated me because they believed I was going to become radioactive and would poison them by walking near them.
In a Radiography department of a hospital – Upto how much time the x-rays(radiation) produced by an x-ray machine stays or lasts in atmosphere?i.e. ( x-ray room)i.e does it revolves in the room for some time or absorbed in air as it travels in straight line?Will it harm the operator?
(Pl Note- Operator takes all precautions while taking x-rays of patients . The query is about the x-rays which are remaining there after the x-ray exposure if any.)Pl reply. thanx
Once the dose is given there is no more danger. Think of it like a light bulb being turned on and off. When the light bulb goes off, it gets dark immediately. There are some few exceptions to this I believe but not in a hospital situation like you described.
I know a fella that was exposed to radiation in some nuclear test and was told
he had been exposed to External gamma dose of 18 REM.
My question — is that a lot? Is that a dangerous amount?
LD50 is around 400 REM and he would likely have to get around 100+ to feel effects. That is a high dose of radiation though. If he got 400 and had no medical treatment he would have a 50% chance of death in 30 days. A full body CT would be around 10 REM. Those are done rarely and I think its about the highest total body dose used in medicine.
[…] https://blogs.agu.org/wildwildscience/2009/09/01/how-much-radiation-does-it-take-to-kill-you/ […]
[…] 20 millisieverts at that time, though he has not yet suffered from apparent radioactive sickness. Cancer cells are very susceptible to radiation; however, and can take years to develop from the original […]
Keep the comparisons to MSV millisieverts. Also, the NLTM non linear threshold model is about to go out the window. It’s archaic in terms of new research. New research is supporting a threshold in which no harm occurs. Go to radiation answers .com for additional education.
old thread but the ‘hormesis’ and this Wade Allison-not-the-one-at-Harvard “10 REM a month is harmless” and such similar claims are being widely promoted again because Fukushima continues to be a concern. They’ll point to background radiation.
It’s like the people who claim three degrees warmer won’t bother anybody because you aren’t bothered when the weather gets three degees warmer.
Fallacy should be obvious.
[…] How Much Radiation Does it Take to Kill You? – Dan’s … – Sep 01, 2009 · One last thing. How much radiation to absolutely, positively give you cancer? Answer: Probably around 20 Sieverts. Notice anything? 5 Sieverts will kill you! […]
[…] http://vmsstreamer1.fnal.gov/VMS…%5B2%5D How Much Radiation Does it Take to Kill You?[3] Cowan–Reines neutrino experiment[4] SN […]
[…] binaries emit between 0.1 to over 100 gigaelectron-volts (GeV) of energy. According to the American Geophysical Union: “Alpha and Beta rays are easily stopped by paper, clothes and skin. Gamma Rays are the bad ones. […]
[…] gamma-ray binaries emit between 0.1 to over 100 gigaelectron-volts (GeV)of energy. According to the American Geophysical Union: “Alpha and Beta rays are easilystopped by paper, clothes and skin. Gamma Rays are the bad ones. […]
[…] binaries emit between 0.1 to over 100 gigaelectron-volts (GeV) of energy. According to the American Geophysical Union: “Alpha and Beta rays are easily stopped by paper, clothes and skin. Gamma Rays are the bad ones. […]
[…] https://blogs.agu.org/wildwildscience/2009/09/01/how-much-radiation-does-it-take-to-kill-you/ […]
What is the easiest way to expose myself and my peers to 1000 rems
If someone is exposed to 6 sieverts of radiation but is relocated and receives medical attention within an hour, what is their chance of survival?
That is usually a fatal dose within a month, but with quick medical attention, From what I have read, I think it might be possible to survive with top-notch medical attention. The odds would be very low though. More of a question for a medical expert in radiation sickness.
Thanks for the great article. I recently bought a Radex radiation detector and keep it in my car, but lost the paperwork on how to interpret the readings! LOL! Now I can stop sweating, though when I was hit by a radar gun, the sieverts went to .22 – to .28 micro sieverts, which made me a bit worried.
Thanks again.
How many xrays will it take to harm a human being ?
I had 33 radiation treatments for Prostate cancer ending October 25th 2018.
Had a p.e.t. test and they said they have found cells still creating p.s.a. which they say I should have none as I had a radical prostectamy in June 2017.
Question I started 28 more consecutive radiation treatments on March 18, 2019 directed at specific area…how much radiation is given each time and is closeness of treatment a question?
I cannot answer this since I’m meteorologist not a radiologist. I can say that this is a case where the benefit of the treatment likely far outweighs the risk.
I had an abdominal CT scan when I was 11..am 19 now….am really worried about the potential health effects that may spring up in the future ….is there any cause for concern?
NONE
I just watched the show Chernobyl. You said in one of the comments that radiation wasn’t infectious or contagious. But in the show the nurses were telling the relatives of the people with radiation burns not to go near them. Why’s that?
Likely because of damage to their immune systems. They could easily catch a bug they could not fight off.
I am concerned about yearly Mammography testing . I am 43 and since I was 35 I’ ve had 3 mammos 1 dental x ray and 1 barium meal test. No cancer history in my family.
I’ really really scared.
Minor amounts. No worries.
I had a friend who worked in radiation medicine. She helped teach new doctors and nurses. One example — radioactive iodine is used to treat thyroid cancer. She would hold up the radio-iodine dose and explain that it’s a very hot gamma ray emitter, then measure the radiation emitted. After showing the new medicos that, she’d ask home many of them would prefer to wear a red apron when treating a patient who’d had a dose of radio-iodine. All, invariably, wanted the shield.
Then she’d put the lead shield in between the hot iodine source and the Geiger counter and the counter would scream.
Then she explained that hot gammas mostly go right on through low masses like people, but when they hit highly massive material like lead, they knock off electrons and produce an intense shower of secondary radiation that’s low enough energy to be absorbed by the Geiger counter or the medcal staff.
Physics 101.
I am a 22 year old female and I use my IPhone 7 Plus at least 4 hours a day. However I never talk on it (I use speaker phone) or put it up to my head. I’m worried that I’m greatly increasing my risk of getting cancer. Am I?
No! Radio waves at that wavelength are non ionising radiation. There is no science that has shown a relationship between non ionising electromagnetic radiation and increased cancer risk.
[…] different wavelengths interact with matter in different ways. For instance, the wavelengths from 380 to 740 nanometers are visible light and are harmless to […]
[…] https://blogs.agu.org/wildwildscience/2009/09/01/how-much-radiation-does-it-take-to-kill-you/ […]
Hello, I work with transporting radiation that we removed from garbage. We drive about 45 mins to an hour with the radiation sometimes reading 1000 from the back of the closed pick up tot he drivers seat. We only do this once a week. Can you tell me how dangerous this, or how long we can drive with how high a dose without getting effects from the radiation? Thank you!
1000 in what units????