Journalist Observation Of Ultraviolet Lamp Entering The House

History is always strikingly similar. On the official website of the China Consumers' Association, the last warning was issued after 2003 SARS.

Ultraviolet disinfection lamp, also known as ultraviolet germicidal lamp and ultraviolet fluorescent lamp, is a kind of lamp that disinfect and sterilize by ultraviolet radiation. Under the new crown epidemic situation, does every family need a UV disinfection lamp?

Zhang Shanduan, deputy director of the electric light source Research Institute of Fudan University, has introduced the ultraviolet disinfection lamp for a long time. It can disinfect the air and water. It used to be used in hospitals, industrial workshops, sewage treatment plants and so on. In recent years, it has gradually spread out in schools, kindergartens, public places, and even into tens of thousands of families.

The bactericidal principle is that the ultraviolet (UV) absorbed by 253.7nm (254nm) wavelength is easily absorbed by the organism, which mainly acts on the DNA of the genetic material of organism. The ultraviolet rays can destroy DNA in a very short time (less than 1 second), resulting in the death of bacteria.

At present, there are mainly two kinds of ultraviolet disinfection lamps for household use in China: one is the common straight tube hot cathode low pressure mercury ultraviolet disinfection lamp. The tube is made of quartz glass or other glass which has high transmittance to ultraviolet, and its power is 40W, 30W, 20W, 15W and so on. Because this kind of lamp radiates 253.7mm ultraviolet radiation, it also radiates part of 184.9nm ultraviolet radiation, so ozone can be produced.

The other is a low ozone ultraviolet disinfection lamp. It is also a hot cathode low-pressure mercury lamp. It can be a real tube type or a H type. Because of the special process and lamp material, ozone production is very low and ozone production is >1mg/h. This is the ozone and ozone free ultraviolet disinfection lamp widely sold in the household market now.

However, ultraviolet radiation needs to meet certain conditions to achieve effective killing of coronavirus. We must pay attention to the wavelength, dose and time of ultraviolet light source. It must be a deep ultraviolet light of UVC band below 280nm wavelength, which is suitable for 30~60 minutes to effectively kill virus and bacteria. In addition, ultraviolet radiation can only sterilize the surface that can be illuminated, and can not produce disinfection effect for less than light. And ozone can diffuse and surpass obstacles, thus giving birth to the market demand of ozone ultraviolet lamps.

On the propaganda page of most products, the ultraviolet disinfection lamp can kill influenza virus H3N2, remove formaldehyde, eliminate odor, kill mites 100% and disinfect 99%.

Zhang Shanduan explained that the mechanism of formaldehyde and odor elimination was mainly due to ozone released by ultraviolet radiation. Because ozone itself is a strong oxidant, ozone and formaldehyde react to produce water, oxygen and carbon dioxide, which play a role in decomposition. But it must be noted that ozone itself is toxic, it will stimulate the respiratory system, high concentration is easy to cause poisoning.

Therefore, we should pay attention to the use of ultraviolet disinfection lamps, especially ozone ultraviolet lamps, and use ventilation for at least 30 minutes. Moreover, the use of ultraviolet disinfection lamps at home must follow the principle of "people turn on the lights, people turn on and off the lights" and leave the room quickly after turning on the lights.

This is because the naked skin is irradiated by ultraviolet lamp, and the light person appears red, swollen, itchy and desquamated. The heavy person will get sunburn or suntan keratosis, and even cause skin tumors and canceration. In addition, ultraviolet disinfection lamp is the invisible killer of eyes, which can cause conjunctiva, corneal inflammation and cataract.

As early as 2003, the Consumer Association of China investigated the market sales of ultraviolet lamps and the usage of consumers, and found that there were many problems: consumers were not aware of their use, improper use methods, manufacturers' warning labels on products were not obvious, and sellers were misleading. These problems still exist more or less.

"Consumers can choose a variety of ways of disinfection and sterilization, not superstition of the omnipotent disinfection of short wave ultraviolet lamp. The sterilization function of ultraviolet lamp is affected by many factors, including exposure time, distance, dust or particle and intensity of light. UVB does not penetrate objects, and most of them are absorbed by plastic and ordinary glass. China Association for consumers is reminded.

17 years later, Cui Song, a health science expert and director of Shuguang Hospital, did not recommend ultraviolet lamp disinfection at the forty-eighth press conference of the Shanghai new crown pneumonia epidemic prevention and control group, especially those with children. "The general family is not recommended nor necessary, because ultraviolet radiation can cause burns to people's eyes and skin. If you want to use it, you must strictly follow the instructions and make sure you can use it in no one's space." Cui Song said.

It is interesting that Ms Hu is the child who buys the ultraviolet lamp. His three-year-old son was diagnosed with allergy as early as possible. Every time he approached the cloth furniture and toys, he coughed. Although the bed sheets were cleaned and replaced every half month, the effect was not obvious. Therefore, although he knew there were many risks to use the ultraviolet lamp, she was willing to try it.

Perhaps, as Zhang Shanduan said, ultraviolet lamps are similar to flashlights to a certain extent, which are emergency supplies in special times. There is no doubt that consumers need to buy them, but as manufacturers, they must fulfill their due responsibilities in product design, publicity and use tips.