Skin penetration radiation

Fig. 4 Skin penetration by UV radiation. Subbands of the UV band penetrate the human skin with varying efficiency. UV-A penetrates the skin and reaches the dermis. UV-B hardly penetrates the epidermis and might reach the dermis. UV-C is totally absorbed within the epidermis...

Fig. 6 Skin penetration by infrared radiation. Subbands of the IR band penetrate the human skin with varying efficiency. IR-A is able to reach epidermis, dermis and even the subcutis. IR-B penetrates into the dermis while IR-C is efficiently absorbed in the epidermis...

One of the limiting quantities in radiological protection against exposure of people is the effective dose (the others being equivalent doses to the lens of the eye and to the skin (e.g. see Section II-8 of Ref. [1]). As this is not a directly measurable quantity, operational quantities had to be created which are measurable. These quantities are ambient dose equivalent for strongly penetrating radiation and... 

Penetrating radiation—Any radiation that can penetrate the skin and reach internal organs and tissues. 

PEL permissible exposure limit OSHA limit for employee exposure to chemicals (29 CFR 1910.1000) based on a time-weighted average of hours for a 40-hour work week Pendant any portable control device, including teach pendants, that permits an operator to control the robot from within the restricted envelope space of a robot Pendant control a means used by either the patient or the operator to control the drives that activate various bed functions attached to the bed by a cord Penetrating radiation any radiation that can penetrate the skin and reach internal organs and tissues... 

Radiation Dosimetry. Radioactive materials cause damage to tissue by the deposition of energy via their radioactive emissions. Thus, when they are internally deposited, all emissions are important. When external, only those emissions that are capable of penetrating the outer layer of skin pose an exposure threat. The biological effects of radiation exposure and dose are generally credited to the formation of free radicals in tissue as a result of the ionization produced (17). 

An important effect of air pollution on the atmosphere is change in spectral transmission. The spectral regions of greatest concern are the ultraviolet and the visible. Changes in ultraviolet radiation have demonstrable adverse effects e.g., a decrease in the stratospheric ozone layer permits harmful UV radiation to penetrate to the surface of the earth. Excessive exposure to UV radiation results in increases in skin cancer and cataracts. The worldwide effort to reduce the release of stratospheric ozone-depleting chemicals such as chlorofluorocarbons is directed toward reducing this increased risk of skin cancer and cataracts for future generations. 

Sunscreens are transparent organic substances that penetrate into the skin and absorb ultraviolet radiation. Common classes of sunscreens include benzophe-nones, PABA derivatives, cinnamates, salicylates, and dibenzoylmethanesJ3 Ben-zophenones have a primary protective range in the UVA region and include oxy-benzone (Fig. 12.9.1), 270-350 nm dioxybenzone (Fig. 12.9.2), 206-380 nm ... 

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