I started to notice that my hair on head and face become more and more greenish as I age. I already have pretty expressive green eyes, so over all it looks kind of cool. The thing is, as I know there are no natural pigment for green hair, so there must be some explanations to it other then just genetics. Am I poisoning myself with something? Like that blue man who ate silver and looked like an alien.

Pic may tell you how it looks right now roughly.