Is inhaling too many negative ions harmful to human body?

At present, there is no report that negative oxygen ions are harmful to the body because of excessive absorption. High concentration of negative oxygen ions is harmless to human body. Moreover, negative oxygen ions have a good health care effect on human body. For example, negative oxygen ions can reduce free radicals, accelerate cell repair and regeneration, and improve the body's self-healing ability. Air negative ions can also excite the respiratory, nervous and immune systems, effectively increasing oxygen supply to the brain. Long-term indoor life of urban residents leads to bad building syndrome, which is characterized by dizziness, fatigue and chest tightness. Air negative ions can effectively alleviate these symptoms. There are many benefits to the human body. The areas with high concentration of negative oxygen ions are mainly areas with good air environment, such as forest waterfalls. With the progress of science and technology, the technology of synthesizing negative ions has also made great breakthroughs. However, in the book Environmental Health and Negative Oxygen Ions, it is mentioned that only small particles with high ecological negative oxygen ion activity can penetrate the blood-brain barrier of human body and play a role in various systems of human body. According to some authoritative organizations, advanced technology negative ion system and active purification technology can produce high concentration of ecological negative oxygen.