What I'm unclear about is, given the global scale of the problem, what's the hold up in demonstrating the effectiveness of the system. Pathogens can be measured in a "before and after" sense. Couldn't they just pick a "dirty" one (or two or three) and clean it up? I'm not a medical guy so I don't know much about procedures, but it doesn't seem like it should be all that much of a problem. Any help appreciated. GL T. GLTA !!