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Human health-related effects

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The impact of ultraviolet radiation on human health has implications for the risks and benefits of sun exposure and is also implicated in issues such as fluorescent lamps and health. Getting too much sun exposure can be harmful, but in moderation, sun exposure is beneficial. Beneficial effects edit UV light (specifically, UVB) causes the body to produce vitamin D, which is essential for life. Humans need some UV radiation to maintain adequate vitamin D levels. According to the World Health Organization There is no doubt that a little sunlight is good for you! But 5 to 15 minutes of casual sun exposure of hands, face and arms two to three times a week during the summer months is sufficient to keep your vitamin D levels high. Vitamin D can also be obtained from food and supplementation. Excess sun exposure produces harmful effects, however. Vitamin D promotes the creation of serotonin. The production of serotonin is in direct proportion to the degree of bright sunlight the body receives....
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Artificial sources

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"Black lights" edit A black light lamp emits long-wave UVA radiation and little visible light. Fluorescent black light lamps work similarly to other fluorescent lamps, but use a phosphor on the inner tube surface which emits UVA radiation instead of visible light. Some lamps use a deep-bluish-purple Wood's glass optical filter that blocks almost all visible light with wavelengths longer than 400 nanometres. Others use plain glass instead of the more expensive Wood's glass, so they appear light-blue to the eye when operating. Incandescent black lights are also produced, using a filter coating on the envelope of an incandescent bulb that absorbs visible light ( see section below ). These are cheaper but very inefficient, emitting only a fraction of a percent of their power as UV. Mercury-vapor black lights in ratings up to 1 kW with UV-emitting phosphor and an envelope of Wood's glass are used for theatrical and concert displays. Black lights are used in applicatio...
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25) Republic Day 2020 Parade FEATURES: Colourful tableaux, daredevilry, armed service might on display

India Republic Day -- The indian subcontinent Republic Day 2020 March, Flag Hosting HIGHLIGHTS: Perfect Minister Narendra Modi paid his tributes to martyrs by laying a wreath at the National War Memorial service in the presence of Defense Minister Rajnath Singh, 3 service chiefs and Key of Defence Staff Bipin Rawat. India Republic Moment Parade 2020, Flag Web host HIGHLIGHTS: India is remembering its 70th Republic Moment Today. The celebration from Rajpath started with Perfect Minister Narendra Modi paying homage to the fallen military at the newly-built National Warfare Memorial on the Republic Moment for the first time instead of the Amar Jawan Jyoti beneath the India Entrance arch. This was followed by President Ram Nath Kovind unfurling the tricolour. The celebration marks the day when India’s Constitution came into effect, along with the country became a republic. Heavylift helicopter Chinook and attack helicopter Apache, both recently inducted in the Native indian Air Force, ...
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