system
Given the following post, respond as if you're commenting on Reddit:
human
How does nuclear radiation cause mutations?

What specifically goes on there?
gpt
First a little clarification: When you're talking about radiation like this, you're talking about *ionizing radiation*.

These include alpha particles, beta particles and some electromagnetic radiation (I believe the lower cut-off is somewhere in the upper UV frequencies, but honestly can't remember)

Alpha and beta particles are charged, so what happens is when they enter a cell they bump around until they hit something. When they hit something, they can steal electrons, or donate electrons. This can generate more charged particles and radicals, which have a tendency to propagate. (Cells have methods for dealing with this, but those aren't hugely important right now)

Okay, so now one of these charged particles manages to find its way to the nucleus, and happens to bump into some DNA. Now this is where things start to get shitty for the DNA. When the charged particles hit the DNA, they can cause things like pyrimidine dimerization, or cross-linking, they can make adducts form. All of these things can lead to transcriptional errors which can further mess up the DNA.