You are right, I don't understand how harmful microplastics are to the human body. I am certainly not in favor of ubiquitous xenoestrogens and carcinogens, but I'm unclear exactly how bad microplastics are to the body and by which environmental pathways they enter the body. It's likely that I lead a life that reduces microplastics to a trace level simply because I'm aware of it, and that this is feasible for most westerners. Regarding the environment, I do not believe nature is an end of itself, so to worry that we're going to destroy the earth or this or that species of fungus is a red herring in my opinion. The purpose of the earth, so far as we should be concerned, is to keep it a sustainable place for humans. If that means we are doing something now that will cause a problem for future generations, one they cannot overcome because of damage done by what we do today, than indeed we must do something to stop it. I don't claim that extinction of an owl or turtle has no effect on the environment, if we get enjoyment out of something existing today, we have no right to take that away from future generations for a short term gain of a few now. There are also unknowable consequences of harming a subspecies or a terrain, where it is better to err on the side if caution than carelessness. If it means those generations of people won't exist at all unless we consume a natural resource today, then we have a nontrivial dilemma. A prime example is the great forest of North America. Generations of Europeans thrived cutting down trees centuries old with trunks wider than any person is tall. That was 100 years ago and the great forest is gone. We wouldn't heed the call of those day's environmentalists, the aboriginal American. Though their reasons appeared irrational, they understood through simple observation that this stripping was not sustainable nor did it preserve the grandeur and benefits of that ancient life for us today. However, if those trees still stood, it is unlikely civilization would have progressed to the point of asking this question of whether microplastics are harmful to an eel. Could we be polluting the world irreversibly and unsustainably with microplastics? Perhaps. If we already have a solution to correct the problem, this answers the question of whether it will be irreversible but it does not answer the question of what are the side effects and what risks are we as a world population willing to take on to reverse a problem where the detrimental effects of microplastics remain in question. To release a new lifeform into the environment that could destroy more than the intended garbage in landfills, perhaps nonplastics or even living things, is yet another example of unconstrained western huberis.