Air that circulates around the sea and on high mountains is high in negative ions and has long been considered beneficial to our health. Indoor air, recirculated air such as that in an office, and air around electronic equipment is very low in negative ions. Many office workers who suffer health complaints around fluorescent lighting and computer monitors report considerably less fatigue and headaches if the concentration of negative ions in the air is increased.
It has been shown that negative ions in the air bind with airborne pollutants, making them heavier so that they fall to the ground, and therefore are unavailable to be inhaled. Many modern air purifiers - the so-called 'ionic air cleaners' - use this technique to provide cleaner indoor air for allergy sufferers. Some studies seem to indicate that an increase in negative ions in the air increases bloodflow to the brain, which would have the effect of improved concentration. The salt lamp is an attractive alternative to the utilitarian look of an air purifier.
The amount of negative ions a salt lamp can release depends on its size and how warm the candle or lightbulb can make it. The larger the crystal, obviously, the more expensive the lamp, but the larger area it can provide with negative ions. Salt lamps that produce 'night-light' amounts of light can provide ions to an area equal to the average office cubicle.