Given how ubiquitous and unavoidable these microplastic particles are, if they have seriously deleterious health effects, then we are facing a slow moving but massive world wide catastrophy. Present day old people may be the last relatively healthy generation for who knows how long. Anyone 40 and under is up the creek if this transpires to be a serious threat.
I guess it was inevitable, that as humans radically change the natural environment and introduce countless novel and untested molecules into the biosphere, that some of them will turn out to be mortal threats to life on this planet. Maybe cockroaches will survive, and if not, then microbes and viruses, lol.