Not to mention the number of masks I've seen worn that have exhalation valves. Assuming that this is actually a valve and not just some bit of plastic stuck on by the guy on eBay you bought it from, exhaled air and droplets will go straight out through the valve thus negating the point of wearing it.I can't imagine many face masks are 3 layer woven cotton, I still believe 99% of the masks used are as effective as a chocolate teapot,
woven cotton fabrics to show that three-layered cloth masks can be constructed with comparable filtration performance to surgical masks under ideal conditions.
Anything you smell is particles so yes, it will absolutely let them in. That's why they fit-test respirators using banana oil, if you smell bananas there's a leak. As for asthmatics, if they're genuine and not just using it as an excuse not to wear a mask, they're probably working on the principle that the very minor risk of catching Covid if they stay two metres from other people is a lesser evil than having their already sub-optimal breathing restricted by a mask.what I’ve noticed is they still let in smells, walk anywhere near the college smoking area and the heavy scent of vape hangs in the air. So if I can smell it would it let in any particles carried with the smell ? Often you’ll hear people say I can’t wear a mask as I have asthma, surely Though getting covid would be far more dangerous ? I don’t know, so many factors.
Now it looks as well lucky us over 50’s will get an extra booster with the Flu jab.
I suspect a lot of people are taking advantage of the fact that mask-exemption has no way of being checked for validity, which rather like back pain, is to the detriment of those who genuinely can't tolerate one for whatever reason.