Heating up plastics is thought to release microplastics but I've not seen much solid research on it either.

According to the European Parliament, ~63% of microplastics come from laundering synthetic clothes and car tires [1].

1. https://www.europarl.europa.eu/news/en/headlines/society/201...

A recent study found that microwaving food in plastic packaging releases a lot of microplastic into the food:

https://news.unl.edu/newsrooms/today/article/nebraska-study-...

I like n+1

https://www.nplusonemag.com/