Nexus - 1003 - New Times Magazine-pages

Page Content (OCR)

vitamin D and thereby on calcium absorption and dental caries spectrum light is not meant to imitate sunlight but, instead, the from using FSFL with extra UV-B; but since the amount of UV-B much cooler light of a cloudy or hazy summer's day, or a skylight added was so small, McColl and Veitch consider it "negligible for from the opposite direction to the Sun on a clear day, since that people with outdoor exposure" and don't rule out other factors has been found to be visually ideal, especially for tasks that contributing to the effect.* Hopefully, future studies may bring require reading and distinguishing colours. But as you can see, further clarification. both directly and in a spectral power distribution chart, it is not a Tf it can be firmly established that extra UV-B really is neces- perfect replication even of that, but more of a greenish-blue rather sary, if it can be determined what dose is needed and are safe for than like the balanced clear-white colour of real daylight. each individual (since this may vary a lot depending on pigmenta- But even if it were possible to reproduce the spectrum of day- tion, etc.), and if it can be proved that artificial fluorescent UV-B light more accurately, would we really want to use it to work in is as good as moderate doses of natural UV-B from the sun are all day? For if we are looking for a light that makes us feel better, said to be, then extra UV-B may be added to any artificial light is it not the warm glow of sunlight that so lifts one's spirit rather source and need not come with FSFL only. than the cold, gloomy light of a cloudy day? And if one is to go A tip for those who may want to try an FSFL tube with extra by what we may be adapted to in an evolutionary sense, isn't it ‘UV-B is to make sure to ask for true that indoors, and during the dark specifics when you buy it, since some part of the year and day, we are, as far of the major manufacturers have now as we know, historically used to the jumped on the "full spectrum" trend even warmer light from hearths, torch- and are selling "health-promoting" es, oil lamps and candles? FSFLs with "extra UV" that include Perhaps this is why most people only UV-A. spontaneously prefer the light of a And if anyone would like to try an warmer colour,’? and may not be as incandescent alternative to a fluores- comfortable in FSFL as some seem to cent light-box for home treatment of think we should be. In a study by SAD, I suggest using the (indirect) Kiiller and Wetterberg (1993), subjects light from one or several 300-watt or experienced more discomfort under 500-watt halogen floodlights, of the aye FSFL of daylight colour than under mains-voltage mini-tube type that composition have not class II warm-white tubes and rated the comes in a rectangular light fitting and been found social status of the room as much lower which can be bought at a low price ina » nee when illuminated by the colder light—which hardware store. I find that, besides effec- to have any significant confirmed the results of an earlier study Although differences in colour temperature and spectral tively "recharging one's batteries" if only it effect on health and (Kiiller, 1982) that showed office workers is bright enough, halogen light also has the reporting more visual complaints when advantage of looking and feeling very much performance, they exposed to the FSFL than under standard like real sunlight. may still influence class III white tubes and finding the daylight Let me add here that halogen lights are colour "unpleasant and cool", especially at now perfectly safe to use. It is correct that how you feel. night.” Many of the other studies reviewed they produce a tiny bit of UV-A, UV-B and by Veitch and McColl showed similar UV-C, and that the quartz glass that the results. Even in the few cases where FSFL bulbs are made of does not stop most of it was actually preferred, they point out the like ordinary glass does. But since this was very likely possibility that it might be due to brought to the attention of the lighting indus- the better colour rendering rather than the try in the early 1990s, virtually all halogen colour of the light." lamps sold today have a front glass that stops UV (and keeps the But to be of good quality, a light does not necessarily have to bulb from accidentally falling out and starting a fire) and/or an be so cold. If one wants to use FSFL, there are other class I tubes extra UV filter on the bulb itself that reduces all UV-C, all or with equally high CRI that give a warmer light. And as shown most of the UV-B and about half of the UV-A. (If one would earlier, incandescent light reproduces colours better than even the actually like it to give off more of the beneficial UV-B, I'm sure _ best FSFL. the filter could be modified to stop the UV-C only. Probably, T'll admit, though, that incandescent light, at the luminance lev- however, it would still be so little that it wouldn't make much of a els usually used indoors, does give colours a bit of a golden shim- difference anyway.) mer compared with how they look in daylight; but in my opinion, So the only thing one needs to think about is to keep these halo- that only looks natural and appealing especially when it falls on gen lights out of reach of children, as they still do get very hot. and enhances the warm colours of most natural materials and liv- Also, they can often be quite glary if not positioned correctly, ing beings as well as on the predominantly warm colours with unless used in one of those glare-free, state-of-the-art light fittings which most of us seem to prefer to surround ourselves. ‘that dentists and surgeons use, which cost a fortune. So why, then, are so many designers, architects and others con- stantly trying to promote both light and colours that are unnatural- Colour Temperature ly cold and bright, as well as cold and hard materials and sharp Although differences in colour temperature and spectral compo- geometric shapes? Even if some of the best designs may be inter- sition have not been found to have any significant effect on health —_esting to look at, does anyone really want to live or work in some- and performance, they may still influence how you feel. Even if thing that is both designed and lit like a morgue? Or use a light the intention was good, I think designing tubes to produce cold- that makes our skin tone look as if we belong in one? coloured light was a great mistake. Let me clarify here that full- Even the neodymium light bulb, which some recommend as an Although differences in colour temperature and spectral composition have not been found to have any significant effect on health and performance, they may still influence how you feel. APRIL — MAY 2003 NEXUS = 39 www.nexusmagazine.com