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Ozone depletion would magnify all of the effects of UV on human health, both positive (including production of vitamin D) and negative (including sunburn, skin cancer, and cataracts). In addition, increased surface UV leads to increased tropospheric ozone, which is a health risk to humans. [61]
The protection of food from photodegradation is very important. Some nutrients, for example, are affected by degradation when exposed to sunlight. In the case of beer, UV radiation causes a process that entails the degradation of hop bitter compounds to 3-methyl-2-buten-1-thiol and therefore changes the taste. As amber-colored glass has the ...
UV radiation is often used to excite a given sample where the fluorescent emission is measured with a spectrofluorometer. In biological research, UV radiation is used for quantification of nucleic acids or proteins. In environmental chemistry, UV radiation could also be used to detect Contaminants of emerging concern in water samples. [101]
Perhaps surprisingly, the effect of temperature is often greater than the effect of UV exposure. [5] This can be seen in terms of the Arrhenius equation, which shows that reaction rates have an exponential dependence on temperature. By comparison the dependence of degradation rate on UV exposure and the availability of oxygen is broadly linear.
Photochemical immersion well reactor (50 mL) with a mercury-vapor lamp.. Photochemistry is the branch of chemistry concerned with the chemical effects of light. Generally, this term is used to describe a chemical reaction caused by absorption of ultraviolet (wavelength from 100 to 400 nm), visible (400–750 nm), or infrared radiation (750–2500 nm).
Air pollution — Atmospheric particulate matter • Biological effects of UV exposure • CFC • Environmental impact of the coal industry • Environmental impact of hydraulic fracturing • Indoor air quality • Ozone depletion • Smog • Tropospheric ozone • Volatile organic compound • Ultrafine particles Light pollution Noise pollution
Sunburn effect (as measured by the UV index) is the product of the sunlight power spectrum (radiation intensity) and the erythemal action spectrum (skin sensitivity) across the range of UV wavelengths. [9] [10] The UV index is a number linearly related to the intensity of sunburn-producing UV radiation at a given point on the Earth's surface.
UV light is considered a key component of prebiotic chemistry on an early Earth. Because of their short wavelengths (10-400 nanometers), UV photons carry enough energy to effect the electronic structure of molecules by interacting with molecular bonds by breaking them (), ionizing them (photoionization), or exciting their electrons (photoexcitation). [4]