It's a screenshot of a character from the TV adaption of The Expanse, Jules-Pierre Mao. He's famous for doing experiments with radiation ::: spoiler minor Leviathan Wakes/Season 1 spoiler and neglecting any human rights while doing so. :::
There's still a lot of rocks and other substances that are very mildly radioactive. Many of them are in your home. You might even call them "bricks".
The fact is it takes a specific level of hazard to affect a person, and bluntly, we're exposed to "safe" radiation levels all the time.
And to finish this, radiation poisoning doesn't require your belief. It will fuck your shit up while you scream about how you don't believe in it. That's a bit like saying that you don't believe in the killdozer at your door, it's not real. Meanwhile, your feeble statements and beliefs, and indeed, your fucking house won't stop the killdozer from murdering the fuck out of you.