Announcement

Collapse
No announcement yet.

lightbulbs and sore eyes

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • lightbulbs and sore eyes

    http://news.yahoo.com/s/ap/20070329/...s/broken_bulbs

    ET



    WEST LINN, Ore. - Most people in the Pacific Northwest can hardly wait for the gray winter rains to give way to spring sunshine. But for four teachers from the Portland suburbs, the lengthening days bring only misery, forcing them to stay indoors with the curtains drawn to shield their stinging, sensitive eyes.

    The four say their eyes were damaged, perhaps permanently, by ultraviolet radiation from a broken high-intensity light bulb of the sort used in thousands of school gymnasiums, factories, big-box stores and other large spaces all across the country.

    At issue are metal halide bulbs, which are about the size of a football and give out bright, white light. The bulbs became available in the 1960s, and millions are in use across the country.

    An outer glass envelope normally prevents the release of UV rays. But metal halide bulbs differ from ordinary household bulbs in that when the glass gets broken — say, by a basketball or a volleyball — the inner quartz tube keeps on burning.

    Exposure to a broken metal halide bulb can burn the corneas. A small number of cases have been reported across the country and around the world, in Florida and South Dakota, Canada and Australia. Exactly how often it happens is unclear, but some experts suspect many cases go unreported or are mistaken for other conditions, such as pinkeye.

    "This is an underappreciated phenomenon," said Dr. William Schaffner, a professor of preventive medicine at Vanderbilt University, who is an expert in the field and not involved in treating any of the four Oregon teachers. "We are sure there are many more outbreaks than get recognized."

    Federal regulators have acknowledged the dangers but declined to regulate the product, suggesting instead that the bulbs be fitted with durable coverings that offer better protection than the wire cages sometimes used in gyms.

    In most cases, the pain goes away in a few days after treatment with over-the-counter drugs. But Kellie La Follette, Denise Fletter, Mary Neerhout Borg and Sherry Rhoades say the pain and sensitivity — which make them feel as if they are chopping onions all the time — have persisted for more than two years.

    During a nearly six-hour teacher training session at a Lake Oswego elementary school gym in 2004, three of the women were seated directly under a metal halide bulb that had recently been broken by a volleyball, the teachers say. The fourth woman, Rhoades, was a phys ed teacher who spent hours in the gym every day.

    By the time the training session was over, some in the room were complaining of sore eyes, headaches and dizziness. On the way home, Fletter rear-ended a car on the freeway. "The brake lights during rush hour were running together," she said.

    La Follette said her eye doctor told her looked like a severe case of snow blindness or welders' burn, clearly indicating UV damage to the corneas — a diagnosis that ultimately helped pinpoint the broken bulb as the source.

    All but La Follette are back at work, but they use eyedrops constantly, wear sunglasses all the time, keep the lights dim and restrict their time outside.

    "I have a strong faith in me, but I just don't know where this will end up," La Follette said at a recent interview at her home.

    The women's doctors have tried all kinds of remedies, including taping the eyes shut and applying a blood serum to the eyes to stimulate growth, to no avail.

    "I am frustrated with the lack of progress we have had," said their optometrist, Todd Briscoe. "We don't know how to treat this."

    In February, a broken bulb was discovered in a middle school gymnasium in Haywood County, Tenn., after 40 children complained of burning eyes and skin rashes, said Timothy Jones, a state epidemiologist. All recovered within a few days, he said.

    Rob McNealey, a contractor from Aurora, Colo., said he spent 10 hours under a broken metal halide bulb at a trade show in Florida two years ago. He said he now suffers from constant migraines and wears specially made moisture-infused goggles.

    "I can't give up," McNealey said. "I have little kids. I am 34. I can't fear the daylight." But "they just don't know how to treat it."

    Jean Peterson, an accountant from Aberdeen, S.D., said her eyes still haven't recovered, a year after she spent eight hours beneath a broken bulb while watching her son's wrestling match. Snow cover and fireworks make her eyes hurt, she said.

    The four Oregon teachers are pushing for a first-of-its-kind state law requiring schools to replace the bulbs with a kind that turns off automatically within 15 minutes after fracturing. Each self-extinguishing bulb costs $12 to $20 more than the standard kind.

    The National Electrical Manufacturers Association has come out against the legislation, saying it would require expensive replacements of light fixtures. Instead, NEMA said, lights in school gyms should have protective coverings made of tough, transparent material such as plexiglass.

    Similarly, in December, the Food and Drug Administration, which claims regulatory authority over the bulbs through its radiological health arm, recommended the use of self-extinguishing bulbs or the protective coverings.

    Sean Boyd, chief of the agency's electronic products branch, said the FDA has investigated at least one incident a year for the past few years.

    The four women are suing Philips Electronics, which manufactured the bulb. A company spokesman denied any responsibility, saying Philips does not recommend using the lights in places where they could get damaged, such as gyms. Other manufacturers include GE and Sylvania.

    "These lights are used worldwide, where children go," La Follette said. "I am completely puzzled as to why there hasn't been a recall."

    ___

    On the Net:

    http://www.uvlightburns.com

    http://www.nema.org

    http://www.leg.state.or.us
    Don't trust any refractive surgeon with YOUR eyes.

    The Dry Eye Queen

  • #2
    Uv

    Very, very interesting. Thanks for posting it. I expect we'll be hearing a lot more about UV exposure and eye damage.

    Charmee

    Comment


    • #3
      Thanks for posting this. Those poor women! I wrote to the reporter and will try to contact their optometrist. With that kind of burns, they sound to me like ideal BSL candidates.
      Rebecca Petris
      The Dry Eye Foundation
      dryeyefoundation.org
      800-484-0244

      Comment


      • #4
        Not Really Suprised

        Well this confirms what I've actually suspected for quite some time. Metal-halide as well as sodium and mercury vapor light bulbs are sometimes referred to as "arc lamps." This is because electricity "arcs" between two contact points within a gas filled tube. This is esentially the same mechanism behind arc welding-which gives off tremendous levels of UV energy. I have had "sunburns" on my arms to prove it. Having been warned about the dangers of "welder's flash"-corneal burns from looking at a welding arc without protection, I am very wary of the inherent safety of these lightbulbs. Having said that, I worked in an aircraft hangar for two years that was brightly lit by these bulbs and never suffered any ill effects. I also remember that my school gymnasium used similar lighting. But I am very distraught that these women are needlessly suffering from something that could have been so easily prevented.

        Comment


        • #5
          Does anybody know or understand just what was meant by the bulbs being damaged? Outer cover or bulb itself? Eli?

          My husband and son work in a building with these lights, which they got used (the bulb is new, though). They bought plexiglass--mounted it on the base of the "shade" to prevent damage and water over-spray hitting the bulbs. My son and I had the discussion recently about whether they give off UV, because he seemed to have a bit of sunburn and we didn't know if it was from the lights.

          Thanks,

          C66

          Comment


          • #6
            As I understand it the problem occurs when the safety cover is broken. The light keeps burning even though there is no longer anything between the UV and you. The warning label on a box discarded years before isn't much help at that point. People exposed to it have no way of knowing anything's wrong until too late.

            Check out http://www.uvlightburns.com. They are advocating regulation to remove these bulbs from schools because it makes no sense to have them in places where they can be expected to break, like gymnasiums with balls flying around.
            Rebecca Petris
            The Dry Eye Foundation
            dryeyefoundation.org
            800-484-0244

            Comment


            • #7
              Bulbs

              I don't really know that much about these lights. However, I think its safe to say that you can think of a metal halide, or any arc lamp for that matter, as kind of a light bulb within a light bulb. The light emitting element is a smallish glass cylinder with an anode and a cathode (basically electrical contacts of different polarity) on either end and is full of a gas that becomes ionized when voltage is applied to the tube. The whole apparatus is then covered with a glass shield that has the familiar "light bulb" shape to it. I am assuming that it is this shield that provides the UV protection. Incidentally, some UV radiation still does penetrate the shield,however, it is mostly UVA which won't cause burns, but has been linked with other problems, such as skin cancer. Flourescent lighting also emits UVA, also know as "long wave" UV. Bulbs used in tanning beds are also flourescent, however they have been "tuned" to also emit UVB light, which will cause the skin to tan (and burn) Just about everyone who works in an office is exposed to flourescent lighting all day long and don't have any problems so, I would say the risks are very minimal. Arc lamps are typically much brighter than flourescent lights and so I would expect the emitted UVA to be stronger. What health risks this may pose, I couldn't say for sure. As far as photokeratitis and skin burns are concerned, you want to stay away from UVB and its evil brother UVC which is an even shorter wavelength. Our atmosphere (for the time being ) blocks all of the UVC emitted from the sun, which is very good because it is extremely damaging to the skin and eyes-this light is however emitted from damaged metal halide lamps which is probably why those people in that gym got such bad eye burns. Incidentally, some lighting fixtures designed for metal halide bulbs are completlely enclosed. Others have a special glass shield that filters all of the emitted light. If you're going to make a homemade shield out of plastic, I would suggest using polycarbonate, or Lexan as it is comercially called. Plexiglass is an acrylic plastic that does NOT block most UV light, whereas Lexan (polycarbonate) does. That's why its used for eyeglass/sunglass lenses. It also has the added advantage of being much more shatter resistant. Lastly, be careful with halogen desk lamps. They use a bulb similar to the one in the headlights of your car. All of these lamps come with a glass filter plate that serves as a UV shield because halogen bulbs apparently emit enough UV to be a problem if not properly filtered. If this plate gets damaged (unlikely, but...) I would suggest not using the lamp until it gets fixed, or you may risk irritating/burning your eyes. Hope that helps.
              Eli
              P.S. I was just thinking that you may want to use caution when designing a homemade plastic shield for your lights. The bulbs can get very hot and might conceivably melt the plastic.

              Comment


              • #8
                Eli--thanks!

                I'm going to check tonight and see what material the guys used for those light covers. We get enough sun UV here in New Mexico USA without adding indoor UV to the problem.

                C66

                Comment


                • #9
                  I advise anyone who suspects that have been fotoceratoconjuntivite (burning eyes caused by light, is any frequency, ultraviolet or not) to do that exam: "multifocal electroretinography (mfERG)". I had an accident with UV-C germicidal lamp (ultraviolet type C) in biological cabinet (not secure), and because of this I had loss of central retinal function that was only detected by the multifocal electroretinogram (mfERG). The "full field electroretinography" and other routine exams to the retina did not detect any abnormality.

                  I think that ultraviolet light caused mutations in the cells of the retina, increasing the number of heterochromatin (condensed regions of DNA that are not synthesizing proteins or other information). These articles describe this:
                  http://www.sciencedirect.com/science...68432802000306
                  http://www.sciencedirect.com/science...68432803000817
                  I think it also may have been mutations with the cells of the ocular surface, ie, there was formation of heterochromatin and these mutated cells failed to express at least part of its function, thereby giving rise to dry eye. Maybe that's why the treatments aren't very effective with me and people with the same type of accident. Well, as permanently mutated cells can regenerate healthy tissues? This is just a theory, because I also think that the ocular surface may be dry as a result of neuronal damage.

                  sorry my english...
                  Last edited by cvowr; 25-Jan-2012, 04:59.

                  Comment


                  • #10
                    Cvowr, thanks for this post! I have gone back and read the previous posts and this all has me thinking . . .

                    Is it possible that lasik induced dry eye works on a similar principle? With the laser manipulation of the corneas, the eyes become super sensitive to light of any kind immediately after the procedure. A natural response to this irritation is for the eyes to tear and close up. However, while the anesthetic has an effect on the eye, the cornea and retina continue to be exposed to the irritating light. I only noticed that my eyes were sensitive to the light after the anesthetic drops wore off. In the recovery area there was some dim light which may have caused some UV damage. Yes I had dark glasses on, but I don't think they eliminated the effect of the light. For my ride home, I had a coat over my head because the light was so painful.

                    Did anyone else have a similar experience after lasik? Could this be the reason some of us are unable to tolerate certain lights? Could this contribute to post lasik dry eye?

                    Comment


                    • #11
                      Great post Lucy! thanks for sharing!! I am so senstive to lights in stores... i didnt realize they were dangerous--luckily i always wear my sunglasses
                      Jenny

                      Comment


                      • #12
                        I had no idea that those types of bulbs were so dangerous. I know I've seen them in warehouses, school gyms and other large buildings. I think the scary part is that the intensity of the light doesn't change when the outer glass is broken. With the sun or even a welders flame, it hurts to look at the light. The question I have is, will these broken lights only hurt your eyes if you look directly at them or can they be damaging by just being in your peripheral vision?
                        Natasha - suffering from dry eyes

                        Comment


                        • #13
                          Queen,
                          Am I to understand you are one of the four? If so, can you recommend an opthamologist who has an interest in DES? I live in Portland.

                          Comment

                          Working...
                          X