“…The higher the air negative ions concentration, the better the air quality is. The air that contains more negative ions have some benefits to debase high blood pressure, asthma, influenza, insomnia, Advance in Ecological Environment Functional Materials and Ion Industry II arthritis, burns and other treatment, can prevent from the development of rickets and scurvy, can improve the ventilation function of lung, promote metabolism, enhance the inhibition of the cerebral cortex, adjust the function of cerebral cortex; and can improve our sleep, our immune system and the quality of life [3][4][5].…”