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EPA Makes a Rad Decision
New submitter QuantumPion writes
"The Environmental Protection Agency released draft guidelines last month that could significantly relax radiation hazard standards in the case of a radiological event in the United States by using risk-based decisions. The goal is to have limits that make sense in an emergency that are different from the limits in day-to-day life. From the article: 'Currently, the only guidance are the extremely strict standards that apply for EPA Superfund sites and nuclear plant decommissioning, which are as low as 0.010–0.025 rem/year, far below the natural background levels in the U.S. of 0.300 rem/year, and even well below the average amount of radioactive materials that Americans eat each year. And these guidelines aren’t really different from the 1992 PAG, except in the area of long-term cleanup standards and, perhaps, standards for resettlement. What’s the big deal here? As radworkers, we’re allowed to get 5 rem/year. 2 rem/year doesn’t rate a second thought. ... No one has ever been harmed by 5 rem/year, so setting emergency levels at 2 rem/year is pretty mild and more than reasonable. ... Think of it this way. The situations covered by these new guidelines are similar to someone dying of thirst who has the chance to drink fresh water having 2,000 pCi per gallon of radium in it. While the safe drinking water levels are 20 pCi/gal for Ra, 2,000 pCi/gal is of no threat, especially if you’re going to die from imminent dehydration. Of course, a bag of potato chips has 3,500 picocuries, so go figure.'"
Radiation Chart
http://www.forbes.com/sites/christopherhelman/2012/03/10/fukushimas-refugees-are-victims-of-irrational-fear-not-radiation/
I'd go on a Vegan diet but the delivery time from Vega is too long. --brownkitty
"We're changing the standards so you can't sue us immediately after the disaster. But if you get cancer 30 years down the line, we and our money will be long gone and no longer giving a darn in Pattaya Beach, Thailand."
[End Of Line]
"Are Irish spuds as highly radioactive as Idaho spuds?"
What do you mean? Russet or Yukon Gold?
Agent K: A *person* is smart. People are dumb, stupid, panicky animals, and you know it.
Of course, potatoes can't be produced from material free of radioisotopes..... http://www.livestrong.com/article/303878-a-list-of-the-most-radioactive-foods/
Potatoes contain gobs of potassium, which has a naturally occurring radioactive isotope (K40). Bananas have the same issue. Unlike C14, K40 is primordial, so everywhere you have potassium, you have essentially the same concentration of K40.
Well, it's not smart to eat a lot of curry, if it's your first time.
Rad, dude!
Chips can't be radioactive if produced from material free of radioactive material.
No such materials exist. At least no such biological materials. Both potassium and carbon are naturally radioactive, and biological matter contains plenty of them.
The fact that there is naturally occurring radioactivity does not mean it is safe to add more. Have a look at studies of increased mortality in nuclear workers from cancer, extra rads do matter and the public should not be exposed. Also, one needs to be very cautious in equating external dose with ingested dose, for some isotopes it may have similar impacts but breathing in plutonium for example is ill advised.
Ever read Physics for Future Presidents? It's a good source of scientific information that should influence public policy more than it currently does.
silly, the people with the higher incidence of cancer in the hiroshima study had exposures of a good fraction of a gray (100 rem), e.g. half a gray at 1500 meters distance. that's way out of the league of what we're talking about here.
Actually Japan didn't ban bananas. The Forbes writer got it wrong.
The new tighter limits on food, water etc. set by Japan were for contamination due to cesium-134 and -137, byproducts of fission usually only found in the wild after a reactor goes wrong or from nuclear explosions. The "natural" levels of radiation from potassium, rubidium etc. are already factored in to the safety regs.
I'm in Japan at the moment, I bought bananas a couple of days ago -- they're a cheap source of energy (and potassium too) since I'm doing a lot of walking around and sightseeing while I'm here.
The only radioactive isotope of carbon is C14. The amount of C14 versus C12 is roughly 0.0000000001%. That is one part in one trillion. A human body has roughly 80 trillion cells.
Yes.
So 80 of your cells contain *ONE* atom of C14. Your whole body contains 80 C14 atoms ...
No. An 80-kilogram person has about 14 or 15 kg of carbon atoms. This works out to trillions of carbon atoms per human cell. Therefore every cell has approximately one atom of C14, and the human body as a whole has almost a quadrillion C14 atoms.
Your math is defective.
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Because "radioactive environment" actually has to be quantified before it's meaningful. You're sitting in a radioactive environment right now. This is what you and the vast majority of Americans who grew up with the X-Men don't understand. So you have to talk about exactly how much radiation you're sitting in.
So let's talk about it. Let's say you weigh 70kg. That means you are made of approximately 7.0 x 10^26 carbon atoms (among other things). Carbon 14, a naturally occurring unstable radioactive isotope of carbon, makes up about 1 in every trillion carbon atoms. That's 1 in 1 x 10^11. Which means there are somewhere around 7 x 10^15 carbon 14 atoms inside you right now. Carbon 14 has a half life of 5730 years, give or take 40 years. That means that several thousand atoms of carbon 14 undergo radioactive decay inside you every second. I'll spare you the math, since there are already too many scary numbers in this post. That means there are thousands of beta particles running around loose inside you, every second of the day. In short, you are radioactive.
And... so what. Those thousands of decay events per second add up to a millirem per year, so tiny it's not even measurable by a normal Geiger counter. You are unavoidably exposed to radiation simply by existing. And here's what matters to you: that radiation you expose yourself to by being made of carbon has no measurable affect on your lifespan, or anyone else's. Something else will kill you first, long before the radiation of yourself induces a cancer inside yourself. Most cancers are chemically induced, not radioactively induced.
Yes, there ARE safe levels of radiation. The numbers matter.
Check your math ... your numbers are implausibly low. Hint: if there were that few C14 atoms in a body, carbon dating wouldn't work.
Quick ban potassium! The potential for dirty bombs is too great....
Oh noooo the bananas!!!!!
-ac because while I know this is funny and trendy I don't feel like being easily indexable by carnivore.
They weren't free of it. The mice had only one fifth of the carbon 14 normally in them.
That's quite an improvement and allowed tracking of tagged substances. But it's still a long way from free or near enough to do truly low radiation studies. It also doesn't address the other radio-isotopes.
It's extremely experimentally difficult to raise animals free of radionuclides. Everything they eat drink or breathe has to be isotopically free of multiple radionuclides. You have to do that for at least a couple generations so that mothers don't pass on so much of the radionuclides from their own blood and tissues to the developing fetuses inside them, or the eggs they lay.
It's been proposed to set up a laboratory to do this for the purpose of setting baselines for radiation standards by comparing what the effect of nearly zero radiation on life is.
The cost would be quite high and as yet there hasn't been a lot of support for it especially from the UN.
No, it's not an indication of any such thing.
Bottom line is that some radiation exposure is inevitable and that some more probably isn't going to kill you, the reality is that ionizing radiation is ionizing radiation and that you shouldn't just assume that you can add more just because you haven't been killed by the radiation in bananas.
What's more, it makes a huge difference if you're prepared for the exposure versus not expecting it. It's normal when working in a nuclear plant to be taking potassium iodide on a regular basis, which isn't something that the general populace is likely to be doing. It's also not typical for the general populace to be wearing protective gear either.
And lastly, it makes a huge difference what kind of radiation you're dealing with and what the duration of exposure is.
Really?
I've never worked civilian nuclear power, but when I was a Navy Nuke, we didn't wear protective gear, nor did we take potassium iodide supplements.
"I do not agree with what you say, but I will defend to the death your right to say it"
Actually, you have to calculate by mass.
http://en.wikipedia.org/wiki/Composition_of_the_human_body#Elemental_composition
16kg of Carbon. From there on, I'd leave the calculation of real numbers as exercise to the reader.
http://en.wikipedia.org/wiki/Carbon-14#In_the_human_body
Now, the kicker is that Carbon, unlike Cesium or Iodine or Strontium or Plutonium, forms part of your DNA. And we have enough Carbon and cells, that about a dozen or so cells will literally have their DNA exploded from within by Carbon 14 *in* the DNA changing to Nitrogen-14.
Go ahead, calculate the exact number if you wish. Keep in mind this time there are about 3,200,000,000 base pairs in every cell's DNA. ;) Which makes a few hundred Carbon-14 per cell *in* the DNA. And since there are (as you say), 80,000,000,000 cells, they are going off like popcorn! And that's just DNA, never mind the much larger rest of the cell.
And then there are the muons that will slam you from above with 1TeV energy every second, light up path, ionizing you from the tip of your head down and out your toes. Thousands to millions of ionized molecules, every second, day or night. And every half a minute or so, one of these muons will stop in your body and blow up like a little bomb.
How would radioactive iodine be released by the normal functioning of a nuclear reactor?
And in abnormal functioning, would the problem of being right next to a nuclear reactor with breached containment make any questions about developing thyroid cancer a few years down the road a rather trivial concern?
Incorrect. Sieverts are specifically designed to account for the differences between radiation types with regards to biological effects. 1 Sv has the same biological impact regardless of whether it was caused by alpha, beta or gamma radiation. If the radiation is given in Grays, then you need to apply correction factors depending on radiation type.
The fact that there is naturally occurring radioactivity does not mean it is safe to add more.
There is some evidence that a small amount of additional radiation is actually good for you. This is called radiation hormesis.
...
Sorry ... hundred thousands of dead people in the decades AFTER the bombs on Hiroshima and Nagasaki and AFTER Chernobyl say something different.
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Yes, they say they don't exist.
Please provide a citation to an actual scientific study supporting these claims. You can't. There aren't any. This is just urban folklore.
The total number of deaths attributable to the atomic bombings, but occurring after October 1945 (when the last of the acutely injured perished) is no more than about 4000 people. Nearly all were individuals that received high levels of radiation exposure close to the bomb hypocenters.
Starships were meant to fly, Hands up and touch the sky - Nicky Minaj
Cesium doesn't linger in mammals. Depending on the tissues it lodges in after inhalation or ingestion (bone, fat, muscle etc.) its biological halflife is between 70 and 120 days i.e. half the cesium taken in will be pissed away or excreted in that time, then half the residue over the next period and so on. It's the same with strontium and a number of other problem specimens in the radiochemical zoo although the half-life varies from element to element.
Iodine-131 is the major contamination problem from fission releases, it's preferentially concentrated in the thyroid and is very radioactive but because of that it goes away quite quickly, with a halflife of only 8 days or so and superdosing with iodine tablets will prevent uptake of I-131 to a large extent. Hospitals and therapeutic facilities that use I-131 to "burn out" thyroid cancers flush residues into the sewer systems leading to the occasional panic when I-131 is detected in miniscule amounts in rivers, lakes etc. downstream.
Yes, eating certain radioisotopes is dangerous. Some isotopes concentrate in areas of the body and emit radiation that is much more harmful when it is in the body (alpha radiation).
However, The chart is given in Sv. Sv takes into account that some radiation is more harmful than others. So, the biological effects from 1 mSv should be the same whether it came from an alpha emmiter or a beta emmiter.
Again, some radionuclides concentrate in parts of the body (others are eliminated quickly - see effective halflife which combines radiological halflife and biological halflife). So, how can we know how many mSv we might get from ingesting one isotope or another? You want to look at commited dose. This is a calculation of how much dose (mSv) you recieve from ingesting some radioisotope. You then use that figure, in mSv, to compare against the chart on xkcd. What you might be interested in is ALI (annual limit on intake). This will give you an amount of a radionuclide (measured in activity or mass) that, if ingested, will give you the highest allowable dose (measured in mSv).
So, you can compare the damage done by various radioisotopes done to you in various ways if you are comparing them in the right units, mSv. But you couldn't compare them just by giving the amount of substance (without considering what kind of radiation and what in the body was irradiated). But, those calculations can be done, and the answer is given in mSv or mrem. This is why the xkcd chart uses mSv for the units, so that a meaningful comparison can be made.
One last thing: Sometimes I wonder; "Is that someone's signature? Or do they type that at the end of each post?"
Since radioactive materials have been actively released into the environment for well over half-a-century, current background levels may not be a good measure of the actual, natural background levels.