I was under the impression that most people have at least a basic understanding of radiation. It looks like I was sadly wrong, though I suppose the necessity of a YouTube video explaining what radiation is in the first place should have been a dead giveaway. Yesterday I wrote a blog post on why saying that GMOs are carcinogens is just plain wrong. Well, today one of anti-GMO people in the YouTube discussion asked if GMOs are tested for radiation. This displays an extreme lack of understanding of radiation and a disturbing lack of willingness to spend 5 minutes Googling something to get even the most basic information before making rather absurd claims about it. So, for those who actually care about being right, it is time for a discussion on radiation.
The simple answer to the question "Are GMOs radioactive?" is no. The reaction you are likely to get from pretty much any scientist who knows anything about radiation, when you ask this question is, "Wait, what the heck are you talking about?"
The long answer starts with the question: How do things become radioactive? First though, perhaps we should look at what radiation is in the first place.
Technically, radiation is any kind of electromagnetic energy that that is moving through space. This includes things like radio waves, visible light, certain forms of heat, as well as UV from the sun, x-rays, and gamma rays. It also traditionally includes certain other types of particles flung through space at extremely high speeds. When people talk about dangerous radiation, they are usually talking about a few specific kinds. There are three kinds of radiation that are generally emitted by radioactive particles. Alpha radiation is the least dangerous, at least in most circumstances. Alpha radiation is when a radioactive atom ejects two protons bound together as helium, at extremely high speeds. This helium nucleus has enough energy to do a great deal of damage, but it is not generally dangerous to humans, because it cannot penetrate the skin. Ingested, however, it could do substantial damage. The second type of radiation is beta radiation, which is just an electron or positron ejected at high speed. This is generally considered more dangerous, because it can penetrate skin, but it generally does less damage than alpha radiation. If a beta decay produces a positron, however, when the positron meets with an electron, they will destroy each other, potentially releasing more dangerous radiation. The last type of radiation is gamma radiation. This is just a form of electromagnetic radiation (much like radio waves or visible light), except that it carries far more energy. Gamma radiation is considered the most dangerous form of radiation, because it can penetrate all the way through the body easily, and it can damage DNA, potentially causing cancer. Keep in mind though, it takes a lot of radiation of any kind to do significant damage. One or two or even a few hundred atoms won't do enough damage to detect.
One more thing that is important to keep in mind is that gamma radiation is not some rare thing that we only see from radioactive substances. Stars and black holes that are many of light years away are producing large amounts of gamma radiation, and very small amounts of that are constantly passing through Earth and through us. There are also other kinds of less well understood radiation in the form of energetic particles from space, called cosmic radiation, that can occasionally interact with DNA, also potentially causing cancer. There is no way to prevent this, though, so we don't generally worry to much about it, and there really is not that much reaching Earth. Most cases of cancer are due to either consuming non-radioactive carcinogens or just normal random mistakes that occur in cells all the time.
So now that we know more about radiation, how do things become radioactive? Just like calling an object carcinogenic, technically calling an object radioactive is wrong. Atoms are radioactive. It is common to call objects containing large numbers of radioactive atoms radioactive though. How does an atom become radioactive? It is complicated, and it requires a lot of energy. One of the simplest radioactive atoms is hydrogen-3, also known as tritium, and it is used in hydrogen bombs. The thing that makes it unique is that it has 2 neutrons and only 1 proton, and having significantly more neutrons (twice as many, here) than protons makes atoms unstable (too few neutrons can also cause instability). It decays into helium-2 (which is stable; that means it is not radioactive) via beta decay, emitting an electron and an electron anti-neutrino (which we won't worry about, because it does not interact much with ordinary matter). Most hydrogen-3 is produced in nuclear reactors, but it can also be extracted from sea water. It is not very common, but it is constantly being produced in oceans when hydrogen in water is hit by certain kinds of cosmic radiation, adding a neutron to the more common hydrogen-2 (which has 1 neutron). In nuclear reactors it is produced the same way, by radiation (usually energetic neutrons) that is emitted from the nuclear reactions that produce energy used to generate electricity. Tritium is safe enough that it is used to make glow-in-the-dark key chains in many places in the world (this is illegal in the U.S., not for safety reasons, but because tritium is also used in hydrogen bombs). More dangerous radioactive elements are generally heavy elements, which are primarily produced in super novas of stars. Regular stars cannot create elements heavier than about iron. Not all heavy elements are naturally radioactive, though a few have radioactive isotopes (an isotope is defined by its number of neutrons, so hydrogen-3 is a different isotope of hydrogen from hydrogen-2). In nature, radioactive elements tend to decay until they become stable elements (or isotopes), but some take millions of years to do this. Uranium is probably one of the most well known radioactive elements, but Radium was one of the first discovered. Radioactive elements can be created in labs, but it takes enormous amounts of energy. Naturally occurring radioactive elements are rare, but they can be found in some places. What it comes down to though is that radioactive elements require huge amounts of energy to make, and they can only be made in large quantities in nuclear reactors and exploding stars.
What about GMOs? How could they become radioactive? The uneducated masses that claim GMOs are radioactive seem to believe that GMOs just magically become radioactive, because they are GMOs. This is completely false. Changing an organisms DNA will not make that organism suddenly radioactive. Some may believe that GMOs can produce radioactive substances, but given the energy required for humans to deliberately make them, it seems incredibly unlikely. Further though, we have never observed an organism that could do this, and if we had, we would certainly be using it to make reactor fuel or even to turn lead to gold. If messing with atoms was that easy, alchemists would have figured this one out hundreds of years ago. In addition, the amount of energy required for a plant to create significant amounts of radioactive atoms is more than any plant has ever collected (even those ancient Redwoods in California would fail this one). The fact is, it is practically impossible. The last problem with GMOs producing radioactive atoms is that if they produced enough to be harmful to humans, they would destroy themselves long before they were ready to harvest. It is just not feasible to claim that GMOs can create radioactive atoms.
If GMOs cannot create radioactive atoms though, perhaps there are other ways they could acquire them. This is true, there are other ways. The most likely way would be for humans to deliberately put them there, but there is no reason for any for-profit company to deliberately kill off their paying customers, and besides, it would be extremely expensive to put enough in to be dangerous. Is it possible it could be happening accidentally? No here too. Modern genetic modification processes work by taking genes (which are just sections of DNA; no radioactive atoms there) from a donor plant and inserting them into the subject plant. This process does not involved enough energy to make radioactive atoms, and it does not involve the use of any radioactive materials, so there is no chance for the resulting GMOs to be radioactive. What about the old technique of bombarding cells with radiation to cause random mutations? This technique probably could create radioactive isotopes, depending on the type of radiation used, but there is no way it could produce more than a very small amount. The problem we have here is that radiation kills things in large amounts, and if you are merely trying to mutate a cell by modifying its DNA you really don't want to kill it. The odds of making more than a few radioactive atoms doing this is extremely low. In fact, it is so low that many companies use irradiation to sterilize chicken eggs before sending them to the retail stores (this is enough radiation to kill stuff, since the goal is to kill bacteria). If there are not enough radioactive atoms in those to be harmful, there certainly won't be in a few plant cells or even a whole seed. Even if there was though, unless the plant is producing radioactive atoms (which it cannot), any radioactive atoms will almost certainly not end up in the edible part of the plant, and _even if they did,_ they would be so diluted that there would not be enough to be dangerous.
There is one other way GMO plants could acquire radioactive atoms, but it is not unique to GMOs. If there are already radioactive isotopes of atoms that are normally absorbed by a plant in the soil it is growing in, then that plant would very likely absorb those atoms along with the non-radioactive isotopes of it. It does not matter if a plant is GMO or not for this to occur though; it will happen with any kind of plant. In theory, this could result in food that is radioactive enough to be harmful, but there is still one problem. If the plant absorbs enough radioactive atoms to harm a human, the radiation will also harm the plant, and probably far more severely than a human. Radiation does its damage in several ways, but the most dangerous is by damaging DNA. This is nothing like adding a gene to a cell though. Radiation has a lot of energy, which means that it could heat a very small part of a strand of DNA, causing a break that prevents it from being read properly. This would likely result in mutant proteins being created, which could tell a cell to multiply uncontrollably, resulting in cancer. Thankfully, most DNA damage just results in the death of the cell, eliminating any further potential for damage. High concentrations of radiation don't just damage DNA though. It can kill a lot of cells, which is what causes radiation sickness. Now, think about a corn plant. It has a lot less mass than a person. So a safe amount of radiation for a person could harm a corn plant. Enough radiation to cause significant harm to a person would harm the corn plant even more, and since plant cells generally divide a lot faster than human cells, the effect would be further amplified (because the damaged DNA is reproduced more). In other words, enough radiation to seriously harm a human would almost certainly kill the corn plant long before it produced any corn. Even if it didn't though, the severe DNA damage would probably mutate the corn plant enough that it would be extremely obvious that something is very wrong with it.
What it all comes down to is that even the old method of genetic modification does not make something radioactive enough to have any more impact than naturally occurring radiation coming from the stars and from space. Plants cannot make radioactive atoms. If plants were picking up radioactive atoms from their farm lands (it would not matter if they would GMO plants or not), if it were amounts harmful to humans, it would kill or otherwise destroy the plants before any food was produced. And even if a for-profit company was stupid enough to make their GMO seeds radioactive, most of the radioactive atoms would be left in the roots and lower stem of the plant, and anything that did get to the edible part would emit less dangerous radiation than the sky (from stars and blackholes and such).
Like I said, the short answer is no, GMOs are not radioactive.
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