Ultraviolet radiation solar

Children Coeur d Alene, Silver Valley, ID Solar radiation (ultraviolet light) Arsenic Estimated number of children with fetal alcohol syndrome. Town contaminated by lead. Sunburn, cancer. Found in drinking water, and old smelter and mining sites, causes skin disease and cancer. 

Recommendations depending on individual sensitivity limit exposure to solar radiation (ultraviolet radiation) reduce energy consumption... 

Solar radiations Ultraviolet emitting equipment Welding arc flash... 

Ozone, which occurs in the stratosphere (15—50 km) in concentrations of 1—10 ppm, is formed by the action of solar radiation on molecular oxygen. It absorbs biologically damaging ultraviolet radiation (200—300 nm), prevents the radiation from reaching the surface of the earth, and contributes to thermal equiHbrium on earth. 

Ozone is formed rapidly in the stratosphere (15—50 km) by the action of short-wave ultraviolet solar radiation (<240 nm) on molecular oxygen,... 

Stratospheric ozone is in a dynamic equilibrium with a balance between the chemical processes of formation and destruchon. The primary components in this balance are ultraviolet (UV) solar radiation, oxygen molecules (O2), and oxygen atoms (O) and may be represented by the following reactions ... 

O Exposure to ultraviolet radiation from the sun is recognized as one of the primary triggers for skin carcinogenesis. Based on their wavelengths, UV radiation is divided into three components UVA (320 00 nm), UVB (280-320 nm), and UVC (200-280 nm).15 UVB accounts for only 5% of the solar radiation that reaches the earth, but it is the primary carcinogenic component in the UV spectrum.15 The following sequence of events describes the process in which UV radiation causes skin cancer (1) UV radiation reaches the earth, and on the skin, it reaches the cells in the epidermal layer (i.e., squamous cells, basal cells, and melanocytes),16 (2) the UV radiation (specifically... 

Applications. Ultraviolet detectors are ideally suited for applications where rapidly developing fire can occur in a relatively open area. UV detectors can be used to monitor ammunition assembly lines, gunpowder troughs, or open areas that are stocked with hazardous materials. These detectors are not typically affected by extremes of temperature or pressure, adverse weather conditions, high humidity, nor are they sensitive to solar radiation. 

Ultraviolet radiation (UVR) is a natural fraction of the solar radiation, and therefore has always influenced life in aquatic ecosystems. The development of oxygenic photosynthesis 2.5-2 J billion years ago (Holland 1984) led to drastic chemical changes in the Earth s oceans and atmosphere. The gradual increase in photosyn-thetically produced oxygen over millions of years was accompanied by a strong enrichment of it in the atmosphere, which ultimately acted as precursor for the ozone (03) layer in the stratosphere. 

Ozone (O3) is formed in the tropical stratosphere, around 12 to 30 miles above the ground, where solar radiation is intense it then migrates to the polar regions. The O3 concentration can be as high as 10 ppm in the stratosphere there, it absorbs a large part of the harmfirl ultraviolet radiation from the sun, thereby protecting life on Earth. CFCs are volatile and persist in the lower atmosphere (the troposphere) because of their inert nature they resist chemical degradation reactions. It is estimated that... 

The UVB radiation causes most damage to skin. UVA radiation is at least an order of magnitude less damaging and is usually harmless to human skin. The UVC solar radiation is all absorbed by ozone and dioxygen of the atmosphere. UVC radiation produced by ultraviolet lamps is usually all absorbed in the epidermis.5... 

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