Solar water disinfection (SODIS) involves exposing water-filled plastic polyethylene terephthalate (PET) bottles to sunlight for several hours. Exposure times vary depending on weather and climate from a minimum of six hours to two days during fully overcast conditions. It is recommended by the World Health Organization as a viable method for household water treatment and safe storage. <answer>Over two million people in developing countries</answer> use this method for their daily drinking water.
How many people use Solar water disinfection to disinfect their drinking water?
Over two million people in developing countries