Apologies if the tag is wrong!
From what I understand, the radiation doesn’t do squat untill it’s ionized. The way it was explained to me is that the Radiation is the knife, while the ionization is the hand weilding the knife.
So how does it affect the body? I know it does something to our DNA but what does it do specifically?
Bonus Question: What did scifi writers assume Gamma Ray’s would do to Bruce Banner to make him the Hulk, as opposed to what it does IRL and just… kill you.
In: 63
Ionising radiation is any form of radiation that creates ions (charged chemical molecules) in the target material. It can do this because it is energetic charged particles (alpha and beta radiation, or proton beams), or because it is energetic and disrupts chemical bonds or atoms (neutrons, x-rays and gamma rays). Alpha and beta particles have low penetrability, and neutrons, x-rays and gamma rays are penetrating radiation.
All cells are a very controlled chemical environment – they have cell walls and transport mechanisms to ensure that the internal cell environment maintains specific conditions. Ionizing radiation affecting the cell causes changes in these conditions by introducing energy, and this energy creates ions – charged chemical fragments. Now, there are lots of ions in the cell, but these are controlled and react in specific ways. The ions created by radiation are highly reactive, and can occur in places where they are not expected.
Sometimes those changes or ions directly affect large and complex molecules like DNA or the molecules that manipulate DNA in the cell – breaking strands or making changes to the sequence of base pairs. This might prevent the DNA (and thus the cell) from operating correctly or replicating. Or it might impact a regulation function, causing the cell operation to change or run out of control – this is what causes cancer.
Sometimes the ions created by the radiation forms highly reactive chemical fragments called free radicals – if the cell cannot provide something to react with the free radical (an antioxidant), it can trigger a chain reaction in the cell, eventually damaging a critical molecule.
If enough damage occur to the cell, it will die. This is the goal of radiotherapy – using penetrating and targeted radiation to kill the cells in a cancerous tumour. This is done by targeting the tumour from multiple directions and by moving the beams – this ensures that the tumour gets a damaging dose of radiation, while the surrounding tissue which is still exposed to the radiation gets a more limited dose.
For more limited exposures, ionizing radiation causes mutations in the DNA of the cell – this could kill the cell, it could make the cell cancerous, or it could introduce a mutation that might be damaging or it might be beneficial. These beneficial mutations are part of how evolution works, along with DNA replication errors. It is this mutagenic effect that leads imaginative writers to posit hulk-forming gamma ray exposure, radioactive spider-bites, or radioactive waste-induced radar-sense along with physical blindness.
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