Most things my body consumes (even the ones it doesn't use) don't fall in to that category. And most of what you're describing our bodies are very good at ignoring. I'm bathed in radiation constantly and I'm fine (unless I stay out in the sun too long without sunscreen...). I wouldn't want to live in a house with asbestos or lead paint, but I wouldn't be too bothered visiting a friend who lived in one. And so on.

It may absolutely be that nanoparticles of plastic are so harmful that eating off of plastic plates is a really bad idea, but my heuristic would be to not worry too much about it.