Mars is littered with 15,694 pounds of human trash: Why is it a concern?

The Mars rover Perseverance had spotted a piece of trash jettisoned during its landing, this time a tangled mess of netting. It's not the first-time scientists have found trash on Mars

from https://www.firstpost.com/explainers/mars-is-littered-with-15694-pounds-of-human-trash-why-is-it-a-concern-11301561.html