Nanotech Water Purifying Tea Bag Millions of people around the world have limited access to drinking water - and diseases caused by contaminated water sources kill 1.8 million people each year. As both private and public entities continue to look for viable solutions to the problem, one promising development comes to us from South Africa, where researchers have used nanotechnology to create a water-purifying tea bag that costs just half a cent. In order to activate the tea bag, the user places it into the neck of a water bottle and then drinks water that passes through it. The design is portable and instantly effective! However, none of this would be possible without the help of nanotechnology - researchers have combined ultra-thin, nano-scale fibers with grains of activated carbon to filter harmful contaminants and kill bacteria.