Es mala la luz negra?

Encontre lo siguiente...

Mirando el tema, me puse a buscar en Internet y encontre la siguiente informacion que espero les sea de utilidad pues yo se que muchos en su afan de modding utilizan las luces UV para sus PC.

C.F.

Tomado de http://members.misty.com/don/uvbulb.html

Fluorescent Blacklights

There are fluorescent tubes that emit UV. The phosphor coating on the inner surface of the tube absorbs the UVC emitted by the low pressure mercury arc, and emits longer UV wavelengths. There are at least six different UV-emitting phosphors used in fluorescent lamps.

One common lamp is the ""BLB" fluorescent lamp. The tubing is made from a very deep violet-blue glass known as "Wood's glass". The tubing is quite transparant to medium and longer UVA wavelengths, and shorter visible violet wavelengths, and a fairly broad range of infrared and the longest, least visible red wavelengths. These tubes emit lots of UV mainly between 350 and 375 nanometers, some of the 404.7 and dimmer 407.8 nM violet mercury lines, and just enough of the blue 435.8 nM mercury line to have a basically blue color when lit. The "BLB" lamps are used for special effects due to their ability to make fluorescent objects glow very brightly.

There is a less common deep-blue-violet lamp with no phosphor and made with special glass (maybe quartz) to transmit the 253.7 nM UVC (shortwave UV) mercury line. These lamps are generally used to make fluorescent rocks glow.

There are UV fluorescent lamps with glass not dyed to block visible light. This includes the BL and the similar 350BL. These are often used to attract insects into electric insect killers. The 350BL has a broader spectrum peaking at a slightly shorter wavelength (350 nanometers) than the BL does, and is supposedly more attractive to insects than the BL.

There are other ultraviolet lamps such as UVB medicinal lamps and UVA suntanning lamps.

There are also the similar fluorescent actinic lamps, producing long UV wavelengths and/or visible violet. These are sometimes used in some special photographic and printing processes. One of these is the 03, specializing in producing visible violet light. The 03 is also used in reef aquariums with live coral since coral utilizes violet and deep blue wavelengths. The 03 actinic will cause fluorescence of most fluorescent dyes, pigments and paints other than ones which fluoresce blue.


Hazards and Precautions
UV has all kinds of hazards.

SKIN HAZARDS

Longer UVA wavelengths emitted by blacklights and general purpose high pressure mercury lamps are basically harmless. Although the hazard is not quite zero, it is generally quite negligible. The same is generally true of any UV-containing light that has passed through ordinary glass.

There is an exception: Some drugs photosensitize skin to ordinarily harmless quantities and wavelengths of UV. Ask your doctor or pharmacist.

Shorter UVA wavelengths cause suntanning. It is widely believed that UV suntanning is not completely safe no matter what you do. Possible ill effects include skin cancers and accelerated aging of the skin.

UVB is much worse, inherently irritating. The skin is designed to take small amounts of UVB and recover, but nothing is perfect here. You probably want to avoid any significant UVB exposure unless a physician recommends UVB exposure for medical purposes.

UVC is even worse, but less penetrating since it is easily absorbed. The outermost portion of human skin is made of dead cells. This layer sometimes gives partial protection from UVC, especially shorter wavelengths. However, don't count on this. UVC is quite damaging to living cells and has nasty burning effects.

EYE HAZARDS

UVA has one nasty effect on eyes, known as "nuclear cataracts". This is a permanent "tanning" of the lens of the eye. "Nuclear" refers to this occuring mainly in the center of the lens of the eye. You need lots of heavy exposure to get this. Nuclear cataracts occur mainly among people who work outdoors.
Although incandescent blacklights emit wavelengths that cause nuclear cataracts, they are largely safe since you typically get less UV exposure from these than from sunlight. Even considering the fact that your pupils are wider under blacklight than under sunlight, there is so much less UV that it is safe to stare into the bulb from a few feet away for large amounts of time. (No warranty, so I don't recommend this.)
Fluorescent blacklights are worse, but are usually comparable to sunlight when you are a couple feet away. Although I have yet to hear of eye damage blamed on reasonable use of blacklights, those who are around them a lot may want UV blocking eyewear.

Persons who have had cataract surgery need extra protection, since the lens of the eye largely absorbs UV. The retina does not like strong exposure to UV.

It should be noted that UVA-related eye damage involves a process with at least two steps. The first step (excitation of tryptophan or related molecules) normally reverses itself. Damage requires excited molecules to receive additional UV before they de-excite. This means that UVA eye damage is not linearly proportional to the intensity of exposure, although it may be proportional to the duration of exposure of a given intensity.

I have yet to see data indicating clearly what is and is not safe. However, nuclear cataracts are most common in people who work outdoors in sunny areas. In case of doubt, use UV blocking eyewear. Cheaper amber and yellow sunglasses do actually work - I have tested them. Sunglass lenses made of real glass and green in color attenuate UV a fair amount. Clear, blue, purple, or pink glasses may not work, even if they are claimed to work. I saw one pair of clear glasses with a sticker claiming "100 percent UV blocking" which let through more UV than window glass did.

UVB is worse on eyes than UVA, and can burn the cornea and the conjunctiva. UVC is especially burning to the conjunctiva. Please beware that symptoms are delayed considerably from exposure. Symptoms typically begin a few minutes after exposure and gradually increase for at least a half hour, often an hour to a few hours after exposure. If you have been exposed and any symptoms begin, promptly seek emergency medical care to minimize damage. NOTE - a doctor has e-mailed me advising that modern medical science can't do that much for UV burns to the eyes.