1972 Nickel Made Of Cooper ?

Looks Very Dirty to me

think it is environmental damage

It is a nickel, but most likely exposed to chemical/chemicals.

Although it's most likely a discolored nickel, I can't dismiss outright the possibility of an off-metal error. First thing you should do is weigh it. If it's the same weight as a nickel, that almost certainly just discolored. Then, just to make sure, you can scrape the edge against a fine sharpening stone. If nickel-colored metal shows up, then there's no doubt it's discolored. If the scrape shows that it's copper-plated, then it was plated outside the Mint.

I know most people frown on invasive tests, but for a coin in as poor condition as this, it won't detract from its value or appearance. I don't regard coins as holy objects; I'll do what it takes to get an answer.

Looks like a parking lot Jeff to me - usually a few in each box.