Negative ions can be be produced by copying any of the ways that nature uses - ultra violet (lamps), radioactive sources etc. Indeed a bathroom shower provides a plentiful supply! But it most cases it is either too dangerous, too expensive or just impractical. For this reason most manufacturers use the method called "corona discharge" which is similar...

Question: What does the ionizer in an air purifier or cleaner do? Should I buy an air purifier that has one? Answer: Many air purifiers or cleaners have built-in, independent ionizers that help to trap airborne particles, to more efficiently clean the air in your home. However, their usefulness can be hampered if the HEPA filter in your air purifier...

USB gadgets are awesome! And now there is a USB gadget that will clean the air! The USB Ionizer Air Purifier actually “emits healthy negative ions into the air which will attach themselves to air molecules and any impure particles in the air and negatively charge them.” The ions purify the air and also remove the toxic substances we breathe in such...