What legal actions can I take after finding a potentially contaminated tissue in my workplace? United States

Hello everyone, I have a kind of odd question, but I am not sure what the proper legal process from here would be. I occasionally work in a lab that is located in an old storage room at a university. I recently tried to throw away a piece of tissue paper on the floor that appears to be contaminated with semen. This tissue has been there for months and I never bothered to pick it up before this, but this space is only ever used by a few people and not very often at that. It is not mine and I am worried the police will think I did it when I report it.

I have not yet told my supervisor about it and I left it there on the ground, but I am really disturbed by this and I am wondering who I should report it to? Any help would be appreciated. Thanks.

Location: United States