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Dermatology, Health Policy, Public Health, Research, Science, Science Policy

The latest twist on compact fluorescent bulbs: They may be UV emitters

Compact fluorescent bulbs (often referred to as CFLs) burn less energy per unit of emitted light. That’s something pretty much everbody can agree on. But that’s about it.

As some readers may know, the U.S. government effectively banned the production of incandescent bulbs going forward by mandating energy-consumption standards no incandescent bulb is likely to meet. At least for the short term, this has tilted the playing field in favor of CFLs.

You either love the temperamental twisted tubes, presumably because they’re energy efficient, or hate them for any of a number of reasons. First, they’re expensive. Worse, because they contain mercury, CFLs have to be disposed of carefully – and should you, heaven forbid, drop one and have it smash into smithereens on the floor, the Environmental Protection Agency says you are supposed to open the windows immediately and clear the room.

I’ve got one in my kitchen. When I turn it on, it takes a while to warm up – and when it finally does, the light it gives off is, well, dirty. It’s depressing. I hate it.

Now, it turns out, there could be a medical reason to hate CFLs too: A recent study in the journal Photochemistry and Photobiology by researchers at the State University of New York, Stony Brook, indicates that, despite advocates’ claims to the contrary, these bulbs give off significant amounts of ultraviolet light, namely in the UVA and UVC range. The SUNY investigators explain that stresses introduced in the bulbs’ X-ray-absorbing coatings during the tubes’ manufacture cause minute cracks or lapses in those coatings:

Closer examination of some of these commercially available bulbs showed multiple defects in their coating, thus allowing UV-light emission. . . . These data are particularly disturbing as the UVC emission is even larger than ambient sunlight on a mountain.

To see if these emissions were physiologically harmful to human skin, the researchers used various biological assays on two kinds of human skin cells: keratinocytes and dermal fibroblasts. For example, the cells were exposed to CFLs so that they got the same UV doses a person’s skin would get from the bulbs after 45 hours at the typical working distance from a desk lamp. The damage to the cells was noticeable and was similar to the kind that occurs in the aging process. (It took only five hours at that distance from a CFL to get UV exposure exceeding recognized safety standards, the scientists noted.)

Ironically, adding either of two forms of titanium oxide (the chief UV-absorbing component of commercial sunscreens) to the skin cells made the damage that CFLs inflicted on them even worse.

Photo by Nioxxe

3 Responses to “ The latest twist on compact fluorescent bulbs: They may be UV emitters ”

  1. peterdub Says:

    It does seem rather odd to ban safe products in place of questionably safe ones
    …normally it’s the other way round!

    This is said to be in the name of progress.
    Better progress is achieved by allowing competition against that which exists.
    Vacuum tubes were not banned (or “phased out” by Government regulation) just because transistors came along – and the tubes retain advantages for certain applications.

    There is no shortage of future electricity sources, and the overall bulb ban savings are small – also because the major usage after 7pm effectively uses surplus electricity anyway ie
    the electricty is produced regardless of whether you switch your light bulb on
    (for operative reasons, with base loading coal plants etc)
    See Ceolas net website.

  2. peterdub Says:

    More about the Stony Brook study here, including the previous similar EU, UK and Canada studies, spectral diagrams of CFL, LED and incandescents and UV information,
    and associated skin disorders

    - and why light bulb regulations don’t make sense, even to save energy, referenced
    http://tonn.ie/2012/07/new-study-on-cfl-uv-radiation.html

  3. Sandeep Saluja Says:

    Do computer monitors let out harmful UV?

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