Earlier quoted context omitted.
You can back that question up one level to "what are the biological effects of plastics?" And the answer is, broadly, they mimic hormones. Compounds in plastics can activate endocrine receptors because they are similar enough to hormones which are more or less everywhere across the animal kingdom. Sometimes it can be hard to pin down the specific negative effects in isolation, but there are some pretty clear metrics.…
The most common plastic, PET, is inert and does not mimic hormones
"When comparing water of the same spring that is packed in glass or plastic bottles made of polyethylene terephthalate (PET), estrogenic activity is three times higher in water from plastic bottles."
https://www.sciencedirect.com/science/article/pii/S096007601...