紫外線對人體的危害及預防措施

一、紫外線對人體的危害：

    波長1OO～400納米的電磁波稱為紫外線。太陽是*的紫外線輻射源，適量的紫外線對人體健康有益．但接觸過量的紫外線會對機體產生危害，特別是對眼睛的損傷。在生產環境中，凡是物體的溫度達1200℃以上時，輻射光譜中即可出現紫外線。電焊、氣焊、電爐煉鋼等作業，以及使用弧光燈、水銀燈、閃光燈、紫外線消毒燈等均可受到紫外線的輻射。紫外線的波長愈短，對人類皮膚危害越大。短波紫外線可穿過，中波則可進入。但接觸過量的紫外線會對機體產生危害。
A, the harm of ultraviolet radiation on the human body:

1 oo ~ 400 nm wavelength of electromagnetic wave is called ultraviolet light. The sun is very strong ultraviolet radiation, the amount of ultraviolet radiation to human body health. But contact excessive ultraviolet ray can produce harm to the body, especially the damage to the eyes. In a production environment, all the object's temperature above 1200 ℃, can appear in the uv spectrum. Electric welding and gas welding, such as electric furnace steelmaking operation, as well as the use of arc lamp, mercury lamp, flash light, ultraviolet disinfection lamp, etc all can by ultraviolet radiation. The shorter the wavelength of ultraviolet is, the greater the damage to human skin. Shortwave ultraviolet ray can be through the dermis, medium wave can into the dermis. But contact too much ultraviolet light can cause harm to the body.

    外線照射皮膚時，可引起血管擴張，出現紅斑，過量照射可產生彌漫性紅斑，并可形成小水泡和水腫，長期照射可使皮膚干燥、失去彈性和老化。紫外線與煤焦油、瀝青、石蠟等同時作用皮膚時，可引起光感性皮炎。紫外線照射眼睛時，可引起急性角膜炎，常因電弧光如電焊引起，故稱為電光性眼炎。Exterior light skin, can cause vasodilation, occurrence erythema, excessive exposure can produce diffuse erythema, and can form small blisters and edema, long-term exposure can make the skin is dry, loss of flexibility and aging. Ultraviolet （uv） and coal tar, bitumen, paraffin wax, effect of skin at the same time, light can cause dermatitis. Ultraviolet light eyes, can cause acute keratitis, often caused by electric arc, such as welding, so called electro-optic ophthalmia.

    紫外線作用于中樞神經系統，可出現頭痛、頭暈、體溫升高等。過量輻射會誘發皮膚癌。另外對眼睛的損傷特別明顯，作用于眼部，可引起結膜炎、角膜炎，稱為光照性眼炎，還有可能誘發白內障，在焊接過程中產生的紫外線會使焊工患上電光性眼炎（可以治愈）。紫外線過量照射皮膚時，可引起血管擴張，出現紅斑、癢、水皰、水腫等；長期照射可使皮膚干燥、失去彈性和老化。紫外線與煤焦油、瀝青、石蠟等同時作用皮膚時，可引起光敏性皮炎。所以無論是在生活中還是在工作中都應該盡量避免紫外線照射。Ultraviolet rays central nervous system, can appear have a headache, dizziness, body temperature, etc. Too much radiation causes skin cancer. Role particularly evident, in addition to the eyes of damage in the eye, can cause conjunctivitis, keratitis, called light eye inflammation, may also induce cataract, the welding process of ultraviolet ray can make welders electro-optic eye inflammation （can cure）. Excessive exposure to the sun's ultraviolet rays, skin can cause vasodilation, occurrence erythema, itching, blisters, edema, etc.; Long-term exposure can make the skin is dry, loss of flexibility and aging. Ultraviolet （uv） and coal tar, bitumen, paraffin wax, effect of skin at the same time, can cause photosensitive dermatitis. So either in life or in work should avoid ultraviolet irradiation.

二、預防措施： 

   預防紫外線的危害應采用自動或半自動焊接。增大與輻射源的距離。電焊工及其助手必須配戴的防護面罩或眼鏡及適宜的防護手套，不得有裸露的皮膚。電焊工操作時應使用移動屏幕圍住作業區，以免其他工種的人員受到紫外線照射。電焊時產生的有害氣體和煙塵，應采用局部排風措施加以排除。
Second, the preventive measures:  
Prevent the harm of ultraviolet （uv） should be used in automatic or semi-automatic welding. Increase the distance and the radiation source. Welders and his aides have to wear special protective mask or glasses and appropriate protective gloves, can not have exposed skin. Welders operating screen should be used when the surrounding areas, in order to avoid other kinds of personnel by ultraviolet irradiation. When welding produce harmful gases and soot, local exhaust measures should be adopted.