Negative ions are beneficial to the human body while positive ions are harmful! Negative ions are charged particles in the air that are mostly formed in nature, and are plentiful next to the ocen surf, waterfalls and in pine forests. Negative ions, which are anti-depressant, increase your sense of well being and clarity by removing the debilitating effects of positive ions. Negative ions hardly live indoors, you have to go outside for them. This is why you feel so much better after a walk in the woods or a stroll next to a waterfall or the ocean surf!