So, every second, there are about 100 trillion neutrinos and tens to hundreds of muons passing through your body per second, and maybe a tiny scattering of neutrons and other cosmic particles or debris from cosmic particles impacting the atmosphere.

Interesting read

1. And every one is named "Betty."

So if they move at nearly the speed of light, let's say 0.99997 c, that's 2.99783 x 10^8 meters per second.

Assuming that you're standing exactly at solar midnight, exactly on the opposite side of the planet as the sun, and all 100 trillion neutrinos are coming from the sun and through your 1.8 meter height, each neutrino will be in your body for 6 x 10^-9 seconds.

So at any given moment, there should be about 600,000 neutrinos in you.

I'm pretty sure all those assumptions are inaccurate, but that's the number I got.

Finally, some hard facts!

Forgot about the theoretical gravitons.

at what amounts do they start getting harmful? Also, how?

Well, one is harmful, if it hits your DNA and gives you cancer.

and yet no superpowers. what a gyp.

There are km wide arrays of hyper-sensible optical sensors in the artic ice to detect the odd collision now and then, so no worries.

Far far less than the charged Neutrons from ground radiation or an un-aired room (Radon). They don't matter at all in health-related things, not even in the devices relying on low-radiation steel from ancient ship wrecks.

3rd Betty liked your comment

More than yours!

(Seriously, I'm a big dude.)