Where on earth do we find pollution?

By all the dirty thing that get in the air. First is a ex:Cars drive all around it can make the air get dirty.When boat drive in the water oil spill out and make the fish die.And also make the water dirty.When people don't care about the land they walk on they throw there junk on the land it make the land dirty and unsafe.The animals will eat the junk left on the land and it not safe for them and then they die.