Here's one that shows masks lose effectiveness over time: https://www.ijic.info/article/view/10788 https://www.ijic.info/article/view/10788 They're using I thi

Here's one that shows masks lose effectiveness over time: https://www.ijic.info/article/view/10788 https://www.ijic.info/article/view/10788 They're using I think single layer of cotton, and 2ply or 3ply disposable paper masks. These are very low quality masks, and if masks work people probably shouldn't be wearing these.