"Change your filters, be they for masks, engines, oil, or water."

Anthony J. Ciani writes in part in the American Thinker,

... One study showed that freshly opened surgical masks reduced the exhalation of bacteria by 75%, but after 120 minutes of use, a surgical mask no longer blocked bacteria, and after 150 minutes, a surgical mask exposed the patient to 50% more bacteria than no mask. Change your filters, be they for masks, engines, oil, or water.

...At my workplace, 13% of the employees have complained to me about how unhealthy they feel wearing their masks. I have overheard retail workers complaining to coworkers about how they feel sick, burning in their lungs, and coughing because of their masks. Masks are the "sorry," not the "better safe." Those at greatest risk from the "WuFlu" venture out, unaware of the odorless death penetrating their masks. Those who are knowingly ill venture out, thinking their masks are protecting others. Wearing masks for hours at a time exposes the wearer's lungs to unhealthy levels of bacteria.

Read more here.