What harm does the humidifier do to the body?

In the north, the indoor humidity is about 40%-60% in autumn and winter. When the humidity in the air is lower than 20%, the indoor inhalable particles increase, which is easy to make people catch a cold. When the air humidity is 55%, germs are difficult to spread; However, if the air humidity is too high, such as more than 90%, it will make the human respiratory system and mucous membrane uncomfortable, and the immunity will decrease, which is especially unfavorable to the elderly, and it will induce the elderly to suffer from influenza, asthma, bronchitis and other diseases. Therefore, people who use humidifiers had better buy a hygrometer to master the indoor humidity. People who already have some diseases need to use humidifiers carefully. In addition, users who use humidifiers should always keep good ventilation. \x0d\\x0d\ The author learned through investigation that inferior humidifiers mostly use inferior electrical accessories, especially power cords, and the outer skin is easy to fall off to expose the copper core, causing electric leakage and electric shock, which brings life danger to consumers, especially to children in hyperactivity period and elderly people with mobility difficulties. Most inferior humidifiers do not have the function of "water shortage protection", or the water shortage protection is invalid, which may easily lead to dry burning, damage and even fire. Moreover, many fans of inferior humidifiers are not produced by regular manufacturers, which is easy to leave fire hazards. \ x0d \ x0d \ Some inferior products blindly pursue cost reduction in order to attract consumers at low prices. The water tank and plastic parts are made of inferior materials, which easily lead to water pollution, odor and physical discomfort during use. Some manufacturers use waste plastics, which are not only poor in texture and easy to be broken and damaged, but also easy to cause secondary pollution because of the unknown source of raw materials. As a humidifier to improve indoor air quality, if more polluted plastics are used, it will produce "fog" pollution and affect human health. At the same time, inferior humidifiers will produce a lot of noise during operation. Noise itself is also a kind of hearing pollution. If the noise is too loud, it will affect normal sleep and rest. \ x0d \ x0d \ Experts point out that in dry environment, the resistance of human respiratory system is reduced, which is easy to cause or aggravate respiratory diseases. Air drying not only has an impact on health, but also has a negative impact on human immunity. Moreover, children's breathing capacity is twice that of adults, and the elderly and children spend less time outdoors in winter, so compared with young adults, the elderly and children are more susceptible to indoor air drying. If inferior humidifiers are used, the pollutants produced will bring health hazards to the elderly and children, making humidification a kind of "bacteria addition". \x0d\\x0d\ The 30-year research by Professor Akiharu Chiharu, who specializes in health and environmental medicine in Japan, shows that the onset of influenza, asthma, allergic dermatitis and emphysema is related to the decline of human immunity after living in a low-humidity environment for a long time.