Was talking to someone and trying to put radiation poisoning and DNA damage into basic terms, could it be said that it is like “flash” cooking living tissue? So depending on the type and amount of radiation a living organism is instantly damaged?
Think about it as an example of the photoelectric effect. The photoelectric effect was a surprising result discovered by Einstein because it showed that there was a minimum frequency of light that was needed to knock an electron loose from its atom, and that below this frequency, it didn’t matter what the intensity of the light was (which is energy/time/area = power/area) - no ionization would occur.
Think of intensity as the “energy flux,” of a light source. The reason why you feel warm when facing the sun is because the sunlight delivers a certain amount of energy per unit time per unit area of your skin.
Now, imagine being tied down to an X-ray machine and having it “shine” on you. You don’t feel warm at all. This is because the amount of energy per unit time per unit area received is very small; much smaller than natural sunlight. But why are X-rays dangerous if the X-ray bursts are of such low intensity?
Because intensity isn’t what matters when it comes to ionizing electrons. If the frequency of the radiation exceeds the ionization energy/Planck’s constant of the electrons in your body, even a low intensity burst of radiation will lead to at least some ionization.
If you were exposed to an X-ray at normal strength all day long, you’re life expectancy probably dropped (or you’re already dead). You’re somewhat screwed. If you are exposed to sunlight (at the surface of the Earth protected by the atmosphere and magnetosphere) all day without sunscreen, don’t sweat it. Just wear sunscreen next time. There are very few natural x-ray sources in the environment, as well as gamma rays. UV rays are within the limit so that they can only cause long-term damage rather than immediate risk of death due to short-term exposure.
Of course, if both the intensity and the frequency are high, then that would be indeed the case in which you are “cooked alive.” An example of that would be underneath ground zero of a nuclear airburst. High frequency gamma rays and high intensity gamma rays combine to vaporize “in a flash.”
But the basic essence of the “cooked alive” can be divided into either being cooked alive from the outside or from the inside. In the case that radiation is of an insufficiently high frequency to consistently penetrate your skin as well as ionize whatever atom or cell the radiation transfers its energy to, then the only damage that can be done to you is from the outside. If the intensity of the radiation is high enough, you’ll be cooked because it gets too hot. But if it’s X-rays or gamma rays, even if the intensity is not very high at all, the radiation that penetrates your skin will disrupt your organs and processes necessary for life, including your genetic material. I’m not sure I would call it being “cooked alive,” you’ll get sick, nauseous, queasy, and incapacitated before you actually feel the insides of your body “burn up.”
It is worth noting that things like the microwaves that cook your food may (potentially) cook you alive but they will not give you radiation poisoning. Sticking your hand in a running microwave is akin to sticking your hand into boiling water.
It’s gonna hurt, you will be damaged but you will not suffer radiation sickness.
Ionizing radiation is the stuff you really want to avoid. Microwaves are not ionizing radiation.
(You’d think this would be common knowledge by now but literally two days ago a co-worker was in our office kitchen standing well away from the microwave and mentioned she want to stay away from the radiation. I told her it wasn’t that kind of radiation and unless she felt herself warming up really fast there was nothing to worry about. I could tell she didn’t believe me. She is otherwise a very bright woman…go figure.)
Cooking is, for the most part, caused by the unravelling/reraveling of proteins in flesh. Simple examplar is cooking an egg white. This occurs at remarkably low temperatures. Indeed, done with care, most things can be cooked at well below boiling point. A cooked organism is of course quite dead. Pretty much all the chemistry needed for life has terminated because a large fraction the chemicals involved in mediating it are no longer in a useful form. These changes of protein form usually involve significant changes in shape of the protein, some wrap up tight and cause large scale physical damage. This is why meat shrinks and expels moisture as it cooks. As cooking progresses more and more damage occurs, but once you reach the cooked egg white stage you are dead.
Radiation damage is different. It disrupts the actual chemistry of the cells. Ionising radiation, by definition, is carried by photons or neutrons with enough energy to be capable of knocking electrons out of orbitals, and are thus capable of creating the raw state for unwanted chemical reactions to occur. Hitting a water molecule and producing an ionised oxygen atom is the sort of trouble you have. This ion will wander about the cell until it finds something to oxidise, probably something important. Damage to individual cell components might be survivable on a cell by cell basis. But you get into trouble on a few fronts. Damage to the DNA - by modifying or breaking the strand. Not just the DNA, but any RNA, or other components of the cell that are involved in the running of the cell. Enough of this and the cell may no longer be able to manage itself, and after some time will die. But critically, DNA damage may be enough to make cell division impossible, because there is damage to components not needed for cell function, but must be intact to allow DNA replication. Stems cells are more vulnerable. This damage can occur at much lower levels of damage than needed to actually kill the cell. Only when the cell needs to divide does it fail, and thus it fails to replenish cells lost in the normal day to day running of your body, you don’t get any replacements, and you eventually die. Running out of blood cells (for instance Aplastic anemia) is going to be fatal. The loss of the ability of stem cells to divide after irradiation will be first seen with the failure of bodily functions that depend upon fast cell replacement. The lining of the gut is another one that is so dependent, and usually one the first to show the effects. Blood (due to loss of bone marrow cells), skin, gut, liver, lung, kidney. The fast replacement cells, these are what you see as the failing body components in radiation damage.
If the radiation is intense enough, enough cell processes are disrupted that enough cells cease to work on the spot, and you die. Outside the blast zone of a nuclear weapon would be a good start. But after that you get into the zone where, whilst alive, you are going to die, as your body ceases to replenish itself. But what you are not, is cooked.
In basic terms, you can be instantly damaged (burned) by radiation, and this is indeed like “flash cooking” but this is not the same as radiation poisoning.
If you are directly exposed (line of sight) to a very intense fire or explosion, your exposed skin will be directly burned by the radiation even at a distance (i.e. even if the air between you and the source is not hot). This is true regardless of whether the source is an exploding gasoline tanker or a nuclear blast, and has nothing to do with radiation sickness or radiation poisoning.
If the “light” that reaches you from the source includes x-rays, gamma rays, etc., it can additionally cause radiation sickness by causing chemical changes to various tissues of your body.
However, this is quite an inefficient means of causing damage - far more effective is to inhale or ingest some material that is emitting ionising radiation. This allows the exposure to be maintained over a period of time, as opposed to what can be imparted in a single flash.
There’s a whole suite of DNA damage detection, and repair mechanisms. Ionizing radiation will damage DNA in all sorts of ways. It will also damage other components of the cell (proteins, organelles, etc.) but those can be easily replaced. But if DNA is damaged, and not correctly repaired, the result is some sort of mutation. Lots of mutations are a Bad Thing, leading to general dysfunction and cancer. Similarly, if a cell has physically “broken” chromosomes, when it divides each daughter cell will have a scrambled and fragmented set of chromosomes. So, when the cell detects DNA damage, it initiates repair mechanisms, and halts cell division until the repairs are complete. Low levels of DNA damage can be repaired, though this process isn’t perfect and sometimes repaired DNA has mutations. Higher levels of damage can’t be repaired, so the cell permanently stops dividing, or hits the “self-destruct” button.
In normal situations, where DNA damage is rare, those response mechanisms are beneficial. If a cell is damaged, you’re better off if it stops dividing or just commits suicide, rather than having that cell go haywire. Individual cells are easy to replace.
But radiation poisoning causes massive DNA damage to all the cells in your body, so that entire organs stop cell division and die. If you could somehow bypass the division block and apoptosis, you’d still be screwed, because now you have massive numbers of mutated cells. Most would still just die, but many would become cancerous.
Plain old cooking will damage proteins and the rest of the cell far beyond any hope of repair, simply killing the cell. It doesn’t matter if there is any DNA damage when the entire cell has been turned into scrambled eggs.