Please, for the love of god, learn about the climate and the impact of human industry on it.
This whole, I travel thousands of miles every year but that's ok because I bought a reusable bag shows a complete lack of proportion and perspective. On top of this, the reusable bags take more resources to produce and often they aren't machine washable so they're thrown out anyways once they're soiled, but that doesn't matter because both carrying options have insignificant impact to the environment compared to most forms of consumption.
Microplastics have a possibility to do bad things to us over the long run by accumulating in our soils, and playing out like a slow train wreck. I have my fingers crossed that saprophytic fungi are already on the case. But it’d be good if someone gave Paul Stamets a research grant.
The water situation is of more immediate concern, and feels more hopeless to a two-rungs-above-armchair environmentalist like myself.
Plastics have a habit of accumulating some pretty bad chemicals like petrochemicals, PCBs, and possibly dioxins but don’t quote me on that one. So ingesting plastic in a lab setting and plastic in the environment may have quite different outcomes.