beats metal shavings I guess...
Maybe not? We already have a variety of metals in our bodies, and cells already interact with them as needed and filtering them if not. (I'm obviously being very generic here. Heavy metals are an obvious exception to this.)
Meanwhile, biology has no idea what plastic is and it seems like our bodies have a hard time filtering it out.
Sorry if you were joking and I missed it.
Sometimes conveyor belts would be left running for days or even weeks in the test area. After a while, you would start to see very fine dust on and around the conveyor belts. This was finely ground POM plastic. On some occasions, there were actually heaps of that stuff forming beneath the conveyor belts.
In the factories, everything gets washed down with pressure washers at least once per day, so very little of this stuff goes into the food, but it definitely gets washed away out to sea.
I think that there is probably a wide-spread misunderstanding on how the micro-plastics enter the food. It does not seem very likely that it would come from the packaging or your tupperware (unless your tupperware is so old that it has actually started to disintegrate). It seems much likelier that the plastics were in the food before it was packaged.