Negative ions (air molecules with extra electrons) are electrically charged particles in the air that remove airborne contaminates and have been shown to have a rejuvenating effect upon our bodies. The best natural generator of negative ions is lightning, followed by ocean surf, waterfalls, mountains and forests. In clean, natural air, you’ll find the highest concentrations of negative ions. In polluted cities and confined spaces, like offices, you’ll find the highest concentrations of unhealthier positive ions. Columbia University has even proven that negative ions can significantly help manage depression and Seasonal Affective Disorder (SAD).