If you drop a gum rapper on the floor is that pollution

Not exactly, it is littering. littering makes the place look unpleasing and unclean, but it wont necessarily kill us. now if a factory is dumping their sewage and whatnot in the water, that is considered as industrial pollution because it is killing almost all the wildlife that live in the water, and it can contaminate the water so if you take a swim in it and accidentally swallow some of the water, it can make you sick and can possibly kill you.

No pollution is in the air, dripping a gum wrapper on the floor is littering