Radiation barrier, skin

Dry, scaly skin is characterized by a decrease in the water retention capacity of the stratum corneum (SC),1 with water content diminished to less than 10%. Barrier function of the SC is usually declined, and transepidermal water loss (TEWL) is increased because of an abnormality on barrier homeostasis.2 People feel tightness of their skin, and the skin surface becomes rough, scaly, and sensitive. Hyperkeratosis, abnormal scaling, and epidermal hyperplasia are usually observed in the dry skin.2 Keratinization also shows abnormal features.2 These phenomena are commonly observed in atopic dermatitis and psoriasis.3 Dermatitis induced by environmental factors such as exposure to chemicals, low humidity, and UV radiation also shows these features. Thus, many researchers have been investigating the cause and treatment of dry skin, and there is currently great interest in adequate model systems for dry skin studies. In this chapter, I will describe several model systems of dry skin for clinical research of dermatitis associated with skin surface dryness and also mention recent studies to improve the dry skin. 

The ozone layer around the Earth has provided us all a natural ring of protection from harmful UV radiation. However, multiple anthropogenic activities have acted as barriers and often caused damage to this shield. Less protection from UV light will, over time, lead to increased health problems and crop damage. Major health problems linked to overexposure to UV radiation by the depletion of ozone include skin cancer (melanoma and nonmelanoma), premature aging of the skin and other skin problems, cataracts and other eye damage, and suppression of normal immune system function.29... 

Ultraviolet (UV) light is directly effective against microbes. Unfortunately, it has low penetrative capabilities and even a thin film will serve as an effective barrier between radiation and microbes. Thus, its use is generally restricted to laboratory applications for surface sterilization. Skin and eyes must be shielded (by glass) from continued exposure to UV light. Ozone (O3) is being used in water treatment. Ozone degrades rapidly in warm water (>35°G/95°F). Thus, at present, its primary application is cold-water recirculation systems. 

Other barrier functions, particularly barrier to water to prevent absorption of excess water. In addition, skin protects the body from ultraviolet radiation, as well as from some chemicals, by limiting the exposure to the upper layers of skin, not deeper tissue. 

For ultraviolet and infra-red radiation, eye protection in the form of goggles or a visor is most important, particularly when undertaking arc welding or furnace work. Skin protection is also likely to be necessary for the hands, arms and neck in the form of gloves, sleeves and a collar. For construction and other outdoor workers, protection from sunlight is important, particularly for the head and nose. Barrier creams should also be used. 

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