Stress

[Reduced tension of the sympathetic nerve system]

(1) When exposed to negative ions, the skin temperature returns to normal more quickly after dipping the hand into cold water. It shows negative ions reduce the tension of the sympathetic nerve system.

(2) When exposed to negative ions, the thenar eminence perspires less while enumerating 10+ vegetables. It shows negative ions reduce the tension of the sympathetic nerve system and it results in reduced stress.

[Reduced fatigue (critical flicker fusion frequency)]

When the negative ion count in the air is high, the critical flicker fusion frequency is high. It means you are not fatigued and can concentrate more. Critical flicker fusion frequency is defined as the frequency at which an intermittent light stimulus appears to be completely steady to the observer. This has been used to measure fatigue levels.

[Reduction of natural Killer cells]

When exposed to negative ions, reduction of natural Killer cells is observed. Immunologically, it shows that stress is reduced.