I think you are doing the community a great disservice by attempting (and failing) to dismiss the research as "fake science" or religious beliefs. Debate over discarding synthetic clothing is different from making bold, unsupported statements that science is fake.
Where did I say the science was fake? I said it's not particularly rigorous, and it's published in a journal with low standards. This is demonstrably true and easy for you to verify if you were so inclined.
You said you don't know what to think. I'm doing my best to help you evaluate the quality of this science. I promise I'm qualified to do so. Being confused about what constitutes quality science is at least as common as getting surprised by the weather on top of Mt. Washington. You don't need to be so defensive.
I can see you put a fair amount of time into this most recent post, and I appreciate your (mostly) civil tone and your logic. I'm happy to grant you the same civility. In order:
1. "
Gathering specimens from all over the world and counting microfibers gives solid, objective data..." Gathering samples from all around the world is fraught unless you're extremely careful in your sample collection. There are a lot of ways for sample contamination to occur: were the jars completely clean? Did fibers from the sample collector's clothes make their way into the sample? What were the fibers actually made out of? (None of these questions are answered adequately in the paper. Read the actual paper and the experimental details yourself.) When you send out jars to a bunch of different people around the world, all of them using their own particular methods to collect the samples, it's exceedingly difficult to control the quality of your samples. When you further choose not to analyze the contents of the jars with any sort of modern analytical techniques, then I'm skeptical.
2. "
The research journal is peer-reviewed..." Not all peer-reviewed journals have the same standards. Standards of scientific quality are measured many ways, one of which is impact factor. Roughly speaking, impact factor is a measure of how often that particular journal is cited in later research. Important, rigorous science is cited often (high impact factor), while poorly performed, meaningless science is rarely cited because it can't be trusted (low impact factor). Again, all of this is pretty easy for you to verify yourself.
3. "
The second article in question was published on nature.com" The Nature publishing group publishes something like 150 journals (they all have web addresses that begin Nature.com/). The journal Nature is one journal out of those 150, and it happens to be one of the most highly regarded journals in current print. Its impact factor is 40. Nature Scientific Reports is a completely separate journal, even though it's owned by the Nature publishing group. Its impact factor is 4. That means it's very far from prestigious. Again, please look all of this up yourself. The fact that they're owned by the same publishing group does not mean they're of the same level of quality.
4. "
To walk the walk, I challenge anyone to find any articles which state that fiber accumulation in marine life is debatable."
Here you go. "Our results indicate, that pollution levels by microfibres have been overestimated and actual pollution levels may be many times lower."
5. "
Here is an additional paper from the National Institute of Health..." This paper is NOT from the NIH. I'm sorry, you're mistaken. This paper is published in Science of the Total Environment, impact factor 3.9, by a group from the University of São Paulo, Brazil. The NIH compiles a searchable list of all published research called Pubmed. This is a searchable database that anyone can use. It's actually a pretty sweet service. But the NIH has nothing whatsoever to do with the articles they compile. They basically just provide the searchable list. What you've linked is the abstract, which is part of the searchable material within Pubmed.
6. "
Here is a link to a major manufacturer..." Good for Patagonia. I applaud them for being proactive.
It's possible 'anthropogenic fibers' are accumulating in marine organisms. It's just that the evidence is thin. There's also little or no discussion of QUANTITY, and the identity of these fibers is left up to our imaginations. These are rather critical details. Finally, there's no mention of what impact any of this is having. More research can and should be done.
The title of this thread is 'Discard your fleece and synthetic clothing immediately.' The evidence that anyone's fleece and synthetic clothing is doing any harm at all is exceptionally thin or nonexistent. On the other hand, a large number of people discarding perfectly good clothing and buying something new creates a new resource burden with definitive negative environmental impact. That makes your advice quite poor and out of line with the ideals of conservation and environmental stewardship. Were that not the case, believe me, I wouldn't be spending my time arguing with you on this forum.