I found this list as well, hope it helps :)
5 NIH studies from 2004-2020 all finding verifiable health effects from wearing a face mask, including scientifically verified reduction is blood oxygen level:
https://pubmed.ncbi.nlm.nih.gov/29395560/
https://pubmed.ncbi.nlm.nih.gov/32590322/
https://pubmed.ncbi.nlm.nih.gov/15340662/