DO you really need proof that poison is bad for you?
My friend once ate what looked like a few nightshade berries. We called poison control, who asked how many. "Three." They immediately said it was fine, and nothing to worry about.
A couple dozen will kill you, three will have no effect.
Water is poison: drinking 50 liters in 1 minute will kill you.
But yes, water will destroy your cellular membranes if exposed to it in big quantities for a long time. Those are chemical (biological) effects.
How about a noble gas? Presumably those are chemically inert enough to not cause anything chemical/biological at all?
> Nonetheless, low reactivity—instead of no reactivity, as had formerly been thought—characterizes the rare gases. One of the factors governing the reactivity of an element is its electron configuration, and the electrons of the noble gases are arranged in such a way as to discourage bonding with other elements.
That said, I would probably classify noble gases as perfectly safe, since damage from exposure to them will more likely come from mechanical interactions, and not biological / chemical.
[1] http://www.encyclopedia.com/science-and-technology/chemistry...
chlorinated pools are also full of poison but that isn't really an issue.