Scientifically speaking why have almost all face masks been wrongly designed? Lack of adhesion means unfiltered air leaks around the edges without passing through any filter. Ear loops make it difficult to fit tightly enough which helps ensure air does leak. (Indeed a batch of face masks got rejected by the NHS just because they had ear loops instead of being tied round the back of the head). It would cost manufacturers next to nothing to fix these defects. Is there a conspiracy to infect the general population?