How do the radiations affect our body cells, and what would happen if they were much higher than normal?
In: Chemistry
There’s non-ionizing radiation – radiation that doesn’t have the energy to make ions out of atoms and molecules (groups of atoms) by removing electrons from the atoms/molecules. This is stuff like radio waves, microwaves, light, etc. This type of radiation generally doesn’t have enough energy to do anything to the cells in your body. There are some dangerous emitters, sort of like the radar on ships or on top of air traffic control towers at airports, that would basically superheat your body like a microwave oven heats up food, but you have to be fairly close to these for them to have this effect because their energy dissipates (spreads out) widely and pretty quickly. Well, the ultraviolet (UV) radiation from the sun can also cause burns if you don’t protect your skin and you stay outside too long (or stay in a tanning bed too long >_>).
And ionizing radiation – radiation that *does* have the energy to make ions. This is the kind of radiation that you find in nuclear reactors, and it comes from sources like uranium, plutonium, radon, how they make x-rays, etc. We’re exposed to this every day in very small doses so that it doesn’t do anything to our bodies. But high rates of doses, like if you were to swallow something that emits ionizing radioactivity, can screw up the structure of the cells in your body. The cells can then either heal themselves like normal, die completely (which is bad) or grow back but they grow back incompletely with mutations. Too many of those and you can end up with diseases like cancer.
Radiation destroys DNA and basically stops cells from getting instructions to do things. Since they aren’t getting instructions to do their job, they die.
Are you asking what would happen if someone had a lot of radiation?
Ionizing radiation causes chemical bonds to break. Some times these chemical bonds are un-important, but other times they hit something more critical such as a DNA molecule.
Cells have repair mechanisms to deal with damage caused by radiation (or other issues). The repair mechanisms take up extra space and energy in the cell, so it makes sense for cells to only have enough repair mechanisms for their expected rate of breakages. If the rate of breakages is higher than the repair mechanisms can cope with, it is likely the cell will mutate or die.
Some types of organisms are more resilient to radiation. These organisms have above average numbers of repair mechanisms in their cells. This is an evolved trait, if organisms are exposed to ionizing radiation, the organisms with less repair mechanisms are more likely to die, and the more resilient cells will breed, creating offspring with even more repair mechanisms.
If the radiation source is removed, then the cells will start to evolve towards having fewer repair mechanisms, since having extra unused repair mechanisms takes extra energy and makes those cells less successful in a low radiation environment.
There is a wide range of different radiation levels occurring naturally on earth. Humans are adapted to deal with the kind of natural radiation levels which naturally occurred on earth in the past. If humans are exposed to radiation levels which are a lot higher than those historical levels, then the repair mechanisms are inadequate. Extra radiation will result in increased mutations, which can lead to increased rates of cancer, especially in the skin, bones, and blood. Even higher rates of radiation will cause cells to die instead of mutate, and humans experience burns and radiation sickness. Enough radiation will results in burns and radiation sickness so severe that it is fatal.
Humans evolve very slowly, so it would take many generations (thousands of years) for humans to adapt to higher radiation levels. Simple single celled organisms adapt much quicker, for instance there are fungi and molds which have adapted to live in the high radiation areas of Chernobyl within a few years or decades of the accident there.
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