Negative air ions are also believed to enhance metabolism, affect emotions and inhibit the viability of airborne gram-positive and gram-negative bacteria.

However, the discovery of negative ions dates back to the late 19th and early 20th centuries. In 1899, German physicists Elster and Geitel were among the first to study air ionization, identifying ...

Negative ions are short-lived and don't float far from the surface, so they were never detected prior to the Chang'e-6 experiment, scientists say.