Search engines [positively] judge content by how poorly it links to other materials. The rest is obvious.
Maybe that's still true so long as other people link to you but you don't link to anyone else...
I could write a fantastic article about this topic but why bother exactly?
https://en.wikipedia.org/wiki/Microplastics
If you go here and examine the article extremely carefully (unrealistically carefully) you would find in the section "Persistent organic pollutants" a link to:
https://en.wikipedia.org/wiki/Endocrine_disruptor
Which links to