Scientists have found that the concentration of negative oxygen ions in the air in Bama in 2,000 to 5,000 / cm ³, known as the "natural oxygen bar", and a few longevity villages negative oxygen ion concentration of up to 30,000 / cm; however, in the majority of cities, this figure is about 1,000 to 2,000. This is less than one-tenth. Bama's high forest coverage, river flushing and high altitude make the air here very fresh and pleasant. Confirmed by medical science, negative oxygen ions can not only play a role in purifying the air, but also make people's spirits, enhance the body's resistance, promote the metabolic process, eliminate respiratory inflammation, alleviate bronchial asthma, stabilize blood pressure, and more importantly, can slow down the aging process, which is an important factor in the longevity of human beings, so people negative oxygen ions figuratively referred to as the "air longevity element Therefore, people call negative oxygen ion as "air longevity factor".