Ah the usual HN tecno-optimism. 1) The human body (and other lifeforms) evolved to adapt to substances found in the environment. That's why a number of synthet

Ah the usual HN tecno-optimism. 1) The human body (and other lifeforms) evolved to adapt to substances found in the environment. That's why a number of synthetic substances are carcinogenic or otherwise toxic. 2) Microplastics contain a very wide variety of plastics. It's extremely unlikely that they are all healthy or neutral. 3) A number of types of plastic are known carcinogens and have been phased out. 4) Given this, he cautionary principle mandates to treat the as harmful by default, unless proven otherwise. There's a reason why drug and food approval processes exist.