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nancyflute
08-22-2004, 11:56 AM
Dear Cecil,

If you have already addressed this issue, please forgive me. I'm a newbie---I did indeed search for it, but maybe I don't know my way around your site yet!

Question: Have you ever come across any evidence of adverse effects of fluorescent lighting?

I ask because first of all, they have always bugged the daylights (sorry) out of me, and 2) a few years back, it became a REAL problem whenever I entered a store with a ridiculous number of the little buggers. It was horribly embarrassing: withing five minutes I would break into a cold sweat; feel quite dizzy, as if I were about to fall; and be on the verge of tossing my cookies. Had to find someplace to sit down ASAP. If any store personnel noticed me, they would ask if I was all right and describe my face as "ash-green."

One time, I was sitting in the pharmacy's waiting area and picked up a magazine someone had left there . . . in it was an article which stated that in Europe, over 90% of all hospitals banned the use of fluorescent lighting because it was "too stressful for patients, and slowed their healing time." Of COURSE, I cannot remember the name of that magazine to save my life, but it was a reputable one, not one of the tabloids!

All of my web searching has led only to the praises of fluorescent lighting in terms of lower costs via saving energy. The only other thing I learned is that the flow of electricity from one end of the tube to the other takes place at 360 times per second! I also happen to have very acute hearing, which comes in handy if you're a musician (which I am), but there is no Off and On switch, so to speak, so even if the fluorescent light is working just fine, the hum it makes really bugs me. Hard on the eyes, too, especially when you do hours of computer work per day.

I even read a lot about the effects of strobe lighting. Remember the "epidemic" of siezures in Japanese children when a new cartoon came on TV that just happened to have a "strobe-like" effect in the background? I also know that strobe lights can trigger seizures in people with epilepsy.

Well, I hope that you can make sense of my litany of grievances! I recently got an Ott Light (full-spectrum), and I LOVE it!!!

Highest regards, Nancy

David Simmons
08-22-2004, 12:19 PM
It is entirely possible that you and others are sensitive to the flicker in flourescent lights. Incandescent lamps also flicker wnen operated on alternating current but much less noticeably. The incandescent fillament dims but does not go black when the current through it reverses. The flourescent goes completely "out" and reignites twice/cycle of the voltage, or 120 times/second.

If you keep your eyes reasonably well fixed relative to your head and move your head back and forth you can see the flourescent flicker. It is entirely possible that while reading, eye movement accentuates the flicker and if you are sensistive to it various effects could easily follow.

Hardly anything is without multiple effects, good and bad. The best we can do is for the good to outweigh the bad or for the good to be necessary so we have to put up with the bad. In a different context that is why I avoid taking any pills unless absolutely necessary and prescribed by a medical doctor.

Q.E.D.
08-22-2004, 12:37 PM
David, most newer instant-start fluorescent fixtures operate in the neighborhood of 20 kHz or so, and have no visible flicker. I've got one in my bathroom. The phosphor also has a certain amount of "lag time" which serves to smooth out any flickering, especially at the high frequencies of electronic ballasts.

But you're right about the old-style fixtures. They also hum (http://www.straightdope.com/mailbag/mbuzzingbulb.html) at 120 Hz, as well, which is even more annoying than the flicker, IMO.