Re: light table (fwd)

Judy Seigel (jseigel@panix.com)
Tue, 3 Dec 1996 01:23:44 -0500 (EST)

On Mon, 2 Dec 1996 wmlaven@well.com wrote:
> . . . in many of
> the UV units I've seen (in my and others' darkrooms) there's only a small
> crack where the light leaks and many people close the printer, then
> proceeed to work near it and the leak is so barely noticeable given the
> brightness of the room (via the general lighting) that they forget they're
> still being exposed to UV rays. As a test, I once closed my dakroom doors,
> turned off the room lights and turned on the UV light unit which I thought
> I had sealed well around the cracks and edges. Although I couldn't see UV
> light emitted with the room lights on, I was amazed at how much holy blue
> glow was actually bouncing around the room. I then resealed the unit until
> it really was sealed as confirmed with my lights-off test.
>
In 1982 when I got my first manufacturer's brochure about UV fluorescent
bulbs, the copy said "contrary to popular opinion, ultraviolet light is
perfectly safe for humans." About 1993 I mentioned this in a phone call
with a technical rep at Philips. After he got done fainting, he said in
effect, "we bought [I think it was Westinghouse] and that is no longer our
position." However, he did say flatly that,

1. past a distance of more than 40 inches [one metre, two centimeters,
about] UV light is perfectly safe, and

2. ordinary glass (such as in eyeglasses or UV goggles) filters harmful
rays/radiation at closer distances.

Perhaps by 2003 this advisory will have been racheted up by the
litigiousness of Americans, say to 40 feet, and full body armor. His tone
and comments did give me the feeling that a lot of the change in position
was positional. I also think of "Overexposure" & its chemical hazards
warnings -- each chemical is defined by the effect if you bathe in it 8
hours a day, which I take to be counter-productive. That is, it may
ultimately lead us to discount actual dangers.

I'll add that I myself have done a lot of hand-dodging by the light of the
Nu-Arc, usually with UV glasses on, but bare hands. I can't seem to scare
up any noticeable effect on the hands, but then I don't sunburn outdoors
either.

Judy