While I appreciate the enthusiasm for citation, none of these are primary sources.
Here is the study (no paywall).
Some questions I had that were answered:
How are gloves made of organic materials contaminating an inorganic sample?
In the manufacturing process, stearate salts are used to remove gloves from molds, these salts have an almost identical size and shape to microplastics.
Does this mean all the old studies are null?
No. Like many scientific studies, this one was conducted in a way that simulates an extreme situation. They tested how much residue was left behind if a researcher were to have pinched a slide between their fingers. However, a professional in a lab should not be doing that. You are supposed to pick up slides by the sides for this exact reason. Some studies may need to be redone, but in general reexamining results is the recommended response.
So are microplastics actually an issue?
Yes. While previous studies MAY have been contaminated, they also may not have been. And even if they were, it’s unlikely results were skewed to the level of ignoring the impact of microplastics altogether. Keep using natural materials, please.