Sunlight does nothing. UV radiation, which you are exposed to in the outdoors, will disrupt a microorganism's DNA, preventing it from reproducing (it doesn't ki

Sunlight does nothing. UV radiation, which you are exposed to in the outdoors, will disrupt a microorganism's DNA, preventing it from reproducing (it doesn't kill the microorganism, though). There's no guarantee that just leaving something out in the sun will penetrate enough to be effective. A glass window filters out almost all of the UVA spectrum, but you can buy a UVA lamp if you want to disinfect the surface of some item indoors. (DO NOT USE THIS LAMP ON YOURSELF). As an example, The SteriPEN uses a UVA lamp to sterilize water, but needs to be on for a sufficient amount of time as the water is agitated. edit I'm an idiot, the SteriPEN uses UV-C, which doesn't even get through our atmosphere. UV-A and UV-B do get through and do affect organisms. Here's a paper on the SteriPEN: https://www.travelmedicinejournal.com/article/S1477-8939(15)00174-X/pdf https://www.travelmedicinejournal.com/article/S1477-8939(15)...