Help or Hinder?
Without any way to actually measure the pollution going into my lungs I just have to trust that this is working. I seems to be. But it also makes it hard to breathe if I'm doing anything other than walking sedately. Going uphill or, worse, up stairs? Walking briskly while holding a conversation? None of those work for me, I end up gasping and ripping it off in a fit of claustrophobia. I have never had asthma, but if it feels like this mask does when I'm arriving at my 4th floor apartment I can understand a little of its horror. That said, this mask IS removable, so it's not too horrible. I'll walk more slowly on polluted days in order to wear it and spare my lungs the junk.<br />Another nice feature: the way it fits adjustably to the nose and cheeks keeps it from fogging my glasses most of the time.  (If I'm talking or moving my face a lot I end up adjusting it every minute or two.)  I don't know how long that little piece of metal inside will last, but so far so good.
Rating: 4 stars