That's interesting! I've been brainstorming ways to expand on this concept, and adding other types of particles is an interesting approach. The neat thing about virus particles (in the context of Meltdown) would be that if they infected some kind of biological "host" object, then that object would start emitting the particles too. So you could kind of chain the particles from one thing to another (by infecting new things) in a way you can't really with nuclear radiation. I'll add it to my list, thanks :)