It's frustrating that people are this retarded. First ozone layer, wikipedia that shit if you didn't make it past 8th grade. Key takeaway, is a fraction of what heads towards earth hits the surface. Second the UV used in tests like this is blasted at the sample. You will not get the same dose outside. Last, sunlight ain't hitting your respiratory system. Leaving a mask in the sun may clean it somewhat, but just use soap on it. Fucking left side of the bell curve with this shit.