| UV Light and its Relationship with Man |
THE SUN
The sun is an abundant source of radiant energy; however, only about half this energy reaches the earth’s surface as sunlight or visible radiation. The other half of the radiant solar energy contains invisible shorter wavelength components (ultraviolet) and invisible longer wavelength components (infrared).
This radiation consists of electromagnetic waves of various wavelengths. Infrared radiation, for instance,
has a greater wavelength than the radiation that makes us tanned. The radiation that makes us tanned we call ultraviolet (UV). Both sorts of radiation are invisible. The visible radiation (light) has wavelengths that lie between the infrared and ultraviolet. Today’s technology has given mankind the opportunity of
reproducing all these forms of solar radiation, so that we now have artificial light (the light bulb for
instance) and also the ultraviolet rays which produce tanning (e.g. sunlamp, solarium).
ULTRAVIOLET
The ultraviolet rays are subdivided into UV-A, UV-B and UV-C. UV-A and UV-B are the parts of the
ultraviolet spectrum which produce tanning UV-C is not received on earth because it is filtered out by our atmosphere.
Your ULTRASUN unit and the special made Ultraviolet bulbs remove the UV-C in the sunbeds and
sunroofs by using a special quartz glass. A further explanation of these regions is described in the
ensuing paragraphs.
SKIN
Like all other organs, the skin is a living part of the body. It is therefore in no sense merely a form of
packing for the muscle system, the tissue, the veins, and the nerves. On the contrary, through the
medium of the delicate and sensitive nerve cells situated in the skin, it conveys to the regulating center
(the cortex of the brain) news of all stimuli affecting the body from the outside. It may therefore be
compared with an extremely efficient radar screen of a large area that receives and registers wavelengths of all types, such as light and heat.
The horny layer of our skin, which is about 1/100 inch thick, consists of scaly cells without nuclei. It
transmits only about twenty percent of the ultraviolet rays with wavelengths less than 300 nm. Of the
rays in the range between 300 and 390 nm, on the other hand, up to eighty percent get through. The
entire outer skin (the epidermis), consisting of the horny layer (stratum corneum), the clear layer
(stratum lutecium) and the reproductive layer (stratum germinativum), causes a twenty percent
weakening of the rays. Ultraviolet rays undergo the greatest absorption is in the papillary layer, the layer in which the nerves end.
Ultraviolet rays of the ordinary wavelengths do not penetrate the skin beyond this papillary layer. This
means that the rays do not get further than one fiftieth of an inch through the one-twelfth-inch
thickness of the human skin. The slight penetration is explained by the fact that when the
ultraviolet rays reach the papillary layer of the skin, they immediately become active participants in chemical processes and are thereby destroyed. The natural consequence of a sunbathe in ultraviolet light is the reddening of the skin.
In harmless cases, the reddening of the skin is followed by a brown tan that lasts for varying lengths of
time. This coloration is caused by the pigment granules that, under the influence of the ultraviolet
radiation, form between the reproductive and papillary layers of the skin. When, after eight to ten days,
the coloration of the skin has reached a point at which the blood vessels can be dilated no further, the
pigment granules inside the skin rise to the top and fade. This restores the pallor of the skin, and the
natural color is gone. Pigmentation of the skin is mainly caused by ultraviolet rays with a wavelength of
less than 310 nm. A tan may be produced without prior reddening of the skin if the skin is exposed only
to ultraviolet rays with a wavelength between 310 and 390 nm. (This is what occurs in your Ultrasun unit with UV-A lamps). A tan created by these long-wave ultraviolet rays is more lasting and finer in color.
People are not all uniformly sensitive to ultraviolet rays. As a rule, a blond person shows a stronger
reaction than a person with black hair; but even among fair people there are variations. The very fair and redheads are more than twice as sensitive as those with the darker shades of blond hair. Age too, and the general physical conditions plays an equally decisive role.
EXPOSURE
“Burn in”: The specially made ultraviolet fluorescent lamps in your Ultrasun unit have to be “burnt in”.
This process requires about 40 - 50 hours. The radiation of the lamps is about 120% of the nominal
power during this period. We advise you to reduce the exposure time during this period by about 20%.
UV-A Longwave Ultraviolet Light and Its Application
The radiation produced in the area of 315 to 400 nanometers (and according to some researchers, part of the visible light rays too) is responsible for the direct tanning which appears soon after irradiation.
UV-B Middlewave Ultraviolet Light and Its Application
The radiation produced in the area of 280 and 315 nanometers is responsible for the direct tanning. The
UV-B radiation produces in the skin a substance known as melanin. This melanin moves to the cells on
the surface of the skin and their changes into pigment.
The fluorescent lamps used in your ULTRASUN unit contains a very small percentage of UV-B radiation
which triggers this process. The discoloration of the pigment present in the cells on the surface of the skin is accomplished by adding UV-A.
A disadvantage of UV-B radiation is that it is very powerful and can irritate the eyes and sunburn
(erythema) the skin. Caution must be used when the body is exposed to this radiation.
Protective sunglasses are a necessity when using UV-B.
UV-C Shortwave Ultraviolet Light and Its Application
The wavelengths in the ultraviolet region below 280 nanometers are known as UV-C. UV-C lamps are
generally known as germicidal lamps. Germicidal ultraviolet is primarily intended for the destruction of
bacteria and other micro-organisms in the air or on exposed surfaces.
The air indoors may contain countless bacterial and mold spores. These are usually the source of
spoilage of perishable products and can cause disease in persons or animals. The germicidal rays
emitted by the lamps destroy micro-organisms so as to maintain a sanitary storage or processing area for products and disinfected environment for persons.
MEDICATION
Certain drugs do not mix well with ultraviolet light, from either its natural, or artificial sources. The U.S.
Department of Health and Human Services has published a booklet entitled Medications That Increase
Sensitivity to Light; A 1990 Listing prepared by Jerome I. Levine, M.S., R.Ph. The booklet is HHS
Publication FDA 91-8280 and is available from the U.S. Government Printing Office. Refer to this booklet
or your health practitioner if you are taking any medications.
Dr. Richard Childers, a dermatologist at the University of Florida, and Dr. Edward Emmett of John
Hopkins University compiled a list of drugs, foods, and other substances that could make your skin
super-sensitive to sunlight. This list is presented below:
- Diuretics (which help prevent water retention), prescribed for high blood pressure (for example, Hydrodiuril).
- Diabetes drugs-Orinase and Diabinase.
- Urinary tract infection treatments with phenothiazines.
- Tranquilizers, such as Thorazine.
- The acne treatment Retin-A.
- Antihistamines--Phenergan and Benadryl--particularly when they are used on the skin in ointment form.
- Antibiotics--Declomycin, Aureozycin, and Griseofulvin, which is used in ringworm treatment.
- Coal tar treatment for psoriasis or chronic eczema.
- Bacterial infection treatments using sulfanilamide.
- Compounds known as furocoumarins or psoralens, which sensitize skin to sunlight whether put on the skin or taken orally. They are prescribed for vitiligo (loss of skin pigmentation) and psoriasis.
- Birth control pills. The hormones they contain can react with sunlight and in some cases cause brown patches on the skin.
- Perfumes and colognes containing furocoumarins, compounds from natural products such as plants and fruits. Their natural oils can sensitize the skin to sunlight.
- Food and fruits that contain photosensitizing agents: celery, carrots, limes, coriander, parsley, fennel, dill, buttercup, mustard, and figs.
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