On cloudy days, ultraviolet rays may be stronger! What problems will ultraviolet radiation cause?

The interaction between ultraviolet rays and substances will produce various effects, and people are taking advantage of this effect. Ultraviolet light has high frequency and photon energy, which will cause strong photochemical reaction and photoelectric effect when passing through the medium, and will also excite some compounds to produce fluorescence. It is found that the germicidal ability of ultraviolet light varies with wavelength, and the peak value of germicidal efficacy is around 254nm, that is, ultraviolet light with wavelength of 254nm has the best germicidal efficacy. In addition, the bactericidal effect of ultraviolet rays is also widely used in medical care and food industry. The most common thing is to disinfect the air and medical items in the ward.

Short-term exposure to ultraviolet rays can cause skin and eye damage, while long-term exposure can lead to cataracts and skin cancer. According to different biological effects, ultraviolet rays can be divided into near ultraviolet rays (UV-A), middle ultraviolet rays (UV-B) and far ultraviolet rays (UV-C). Among them, near ultraviolet rays with a wavelength exceeding 3 15nm can penetrate the glass and reach the dermal layer of the skin directly. It has a black spot effect on human body. It can be used for ore identification, stage decoration, banknote inspection, mosquito attraction and other places. Mid-ultraviolet light, with wavelength of 280-3 15nm, has erythema effect on human body, can promote mineral metabolism and the formation of vitamin D in the body, and is mainly used for fitness and beauty, and promotes plant growth. Far ultraviolet rays with a wavelength below 280 nm cannot penetrate transparent glass and plastic. Short time will burn the skin and mucous membrane. Mainly used for disinfection in hospitals, restaurants, schools, home cabinets and other places. The shorter the wavelength, the worse the penetration ability, but the stronger the ability to destroy human skin and mucosa.

Ultraviolet light comes from a variety of light sources, including natural light sources and artificial light sources. Among them, natural light is mainly sunlight, while artificial light sources are more common in ultraviolet lamps, arc welding and so on. People who are exposed to a lot of sunlight reflecting ultraviolet rays are mainly outdoor workers, especially in mountains, glaciers, snow, deserts and oceans. The ozone layer is the main absorption zone of solar ultraviolet radiation, but because environmental pollution will destroy the ozone layer, the ultraviolet radiation on the surface of the earth will gradually increase. Short-term exposure to a large amount of ultraviolet rays will seriously damage people's skin and eyes, and long-term exposure will lead to cataracts and skin cancer. In summer, at noon and at higher altitudes, the ultraviolet index is higher; Glaciers and snowfields reflect strong ultraviolet rays, which will greatly increase the amount of ultraviolet radiation.

There is no specific change in lens damage caused by external radiation. There is no report of occupational cataract caused by ultraviolet rays in China. Acute electro-optic ophthalmia is characterized by rapid onset, high incidence and good prognosis in many cases.