Talk:Over-illumination

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Contents 1 Daylight? 2 Over-illumination 3 DYK! 4 Exclamation point 5 Delamp? 6 Statistics? 7 Control studies 8 Movie use? 9 Electricity wasted? 10 Reverts 11 Circulatory and circadian rhythm effects 11.1 Wording 12 Terminology: Natural vs Day vs Sun -light 13 Light pollution 14 Occupancy Sensors 15 General critique 16 Causes 17 Fluorescent Lamp Wearout 18 Sleeping with the lights on 19 broken link 20 Wasted oil reference

[edit] Daylight?

Even the most intense artificial indoor lighting is usually many times less-intense than normal daylight. It srikes me as pseudoscience to claim that we are so badly-adapted to the natural world that relatively-dim artificial indoor lighting would be "too bright" to allow humans to thrive. There may be many things wrong with artificial lighting, but "too bright" seems to me like a specious claim. -Atlant 21:07, 15 May 2006 (UTC)

Your point is an important one, which is one reason why the article stresses the artificial colour spectra and flicker effects as contributory to deleterious effects. Regarding the evolutionary implications of your comment, prehistoric man had not enough life-span to worry about such nuances as headache and small increases in hypertension.

Other points worth noting are that a small fraction of prehistoric or modern man toil in bright sunlight for 8 hrs per day. further, havent you ever been on a two hour long hike in bright sun and experienced headache from brightness? regards Anlace 21:17, 15 May 2006 (UTC)

Sorry, no. Aside from snow blindness induced by highly-reflective surroundings, I enjoy high levels of illumination. -Atlant 14:31, 16 May 2006 (UTC)

I agree. I don't buy the claim that too much light leads to health problems. Even on a cloudy day, daylight is at least ten times more intense than the brightest office environment. Too much of the wrong spectrum of light, I can accept. The article seems to conflate together concerns about energy conservation and health impacts in a way that seems a bit unscientific (or pseudoscientific). The current text seems maybe a little better than earlier versions. I think still more separation is needed between the issues of too much use of artificial light instead of natural light being bad for energy efficiency, and artificial light vs. natural light being bad for health. The former is a matter of too much; the latter is a matter of wrong kind—not really "over-lighting" at all. They are related only in that increased use of natural light happens to solve both problems.--Srleffler 03:53, 17 May 2006 (UTC)

I dont think all the research has been done that will fully elucidate these discussions. the whole matter may be even more complex than indicated here. For example some of the research indicates blue eyed (northern latitude evolved?) people are more sensitive to bright light stimulated migraine. Who says that because man evolved in this climate on earth he is perfectly adapted to the meteorology and solar insulation? In any case I am open as to how the data are presented. Clearly the research data are not clear as to what fraction of the harm is from improperly matched spectra vs brightness. Regards. -Anlace 04:22, 17 May 2006 (UTC)

The article needs to be clear about what has and hasn't been supported by research. Anything that hasn't been at least described in print elsewhere needs to be removed, per WP:NOR.--Srleffler 04:52, 17 May 2006 (UTC)

Perhaps they are not considered bright in reference to direct sunlight... but in many cases, humans would live under trees, or in their own shelters, wouldn't that reduce the light some? Possibly to levels lower than the light hitting you straight in the eye from the source in a mall? Tyciol 06:58, 19 June 2006 (UTC)

[edit] Over-illumination

I haven't had a chance yet to read it in depth, but it looks fascinating, and a clear WP:FA candidate. Great job! Postdlf 18:47, 15 May 2006 (UTC)

It has some NPOV issues to be cleared before this becomes a good article. I'll work out some of the minor ones tomorow. Dilbert 23:58, 15 May 2006 (UTC)

I conducted considerable additional work to improve NPOV and add further references. -Anlace 14:03, 16 May 2006 (UTC)

[edit] DYK!

An entry from Over-illumination appeared on Wikipedia's Main Page in the Did you know? column on May 15, 2006.

Thanks for your work on this article! I agree, fascinating stuff. ++Lar: t/c 21:49, 15 May 2006 (UTC)

[edit] Exclamation point

"A survey of building managers indicates this practice was primarily for the convenience of the janitors, so that they would not have to bother turning lights on and off during night shifts when janitorial work was carried out!"

I'm too timid to edit it out, but that exclamation mark somehow seems less than encyclopedic... —The preceding unsigned comment was added by 24.146.25.124 (talk • contribs) 18:14, 15 May 2006.

The exclamation mark has been removed (not by me however). Please sign your comments using four tildes. Dilbert 23:57, 15 May 2006 (UTC)

You can root around in the history and add an {{unsigned}} (with a leading subst: if you want to help people out who forget. I did, above. ++Lar: t/c 01:26, 16 May 2006 (UTC)

[edit] Delamp?

Is that a neologism?Lukas 02:04, 16 May 2006 (UTC)

Good point Lukas. Yes its a technical term coined in the early 1990s when large scale delamping in many office buildings first came into vogue to correct certain over-illuminated office buildings Anlace 11:42, 16 May 2006 (UTC)

[edit] Statistics?

700 Million wasted each year? It doesn't add up -GarlicBreath 04:20, 16 May 2006 (UTC)

You are raising an important point Garlic. Perhaps the article should state million barrels per day (petroleum equivalent), since much of the electrical energy used to power lighting derives from hydro, nuclear, coal and other renewables. I think the total daily energy consumption worldwide is about 80 million barrels per day. The diagram you reference is petroleum based energy source only at about 27 million barrels per day. You can also consult light pollution where a separate accounting of illumination energy wastage is calculated using two different methods. Anlace 11:50, 16 May 2006 (UTC)

[edit] Control studies

A lot of speculation in this article - where is the evidence for these quoted clinical effects? (and I mean proper scientific evidence, eg randomised controlled trials, (although that would be difficult, but even properly done case control studies would be better than nothing) not just opinion.) The reference list is woefully inadequate. Improve the references or state that most of the page is unsubstantiated opinion.210.54.1.141 05:24, 16 May 2006 (UTC)

Interesting comment in that this article has more thorough referencing than 95 percent of wikipedia articles. more specifically, there are several references supporting headache incidence including contol studies (refs Burks, Boyce, Lumina); references on other issues have been expanded and notes have been added stating where control studies have not been done.Anlace 12:16, 16 May 2006 (UTC)

I don't dispute the number of references, just their ability to prove some of the stated assertions. Doing a survey along the lines of 'do you find that artificial light causes you to have a migraine?' proves nothing except that the study is poorly-designed and of no statistical weight. In any case, correllation does not prove causation, so even if a case-control study finds an association between artificial light exposure and migraines/hypertension/whatever we could not say the light caused the effect with any more validity than we could say that the chemicals used in cleaning most of the office floors where the subjects worked caused the effect. Some of the assertions in this article are biased, not neutral point of view, unscientific, and bordering on pseudoscience. It would be best to change these statements to , eg, "Some believe..." etc, and acknowledge that although what is postulated may be true, it has not been proven. 202.154.128.44 10:12, 19 May 2006 (UTC)

You are fighting a straw man. none of the studies nor the article lead the participants in the studies with the leading question you invented. for example in the migraine survey, no mention of light of any kind was given in this controlled study, and in fact 47 % of the respondents identified bright light as the principle trigger of their migraine. In the office building studies, careful controls were taken to assure that no other maintenance changes (e.g. cleaning chemicals, building humiditity etc) took place. in the lumina study, again, participants were not prompted on "lighting" but were simply asked what their incidence of headache was (before and after lighting changes). Again the participants in the studies were not informied lighting changes had occured and most participants were totally unaware of the lighting changes. what is more remarkable is that no studies have surfaced to prove that such health effects do not occur, even though some such studies (initiated mostly by the lighting industry) have been attempted. by the way you didnt acknowledge that some alteration of the text has already occured to qualify the strength ot the health effects assertions :), regards Anlace 21:11, 19 May 2006 (UTC)

[edit] Movie use?

Over-Illumination is used in alot of movies to create a certain feel, to put the viewer on the edge and accentuate something. Some scenes in Dawn of the Dead (new remake) have this, along with some cyberpunk themes (maybe the Matrix). I'm not sure, but it is obvious that in many movies it seems that there is excessive lighting used in certain scenes to add to the scene. This element is also used to accentuate aggravating working environments in certain movies.

It is probably because Over-illumination looks 'cool', 'advanced' and 'different' at first impression but over time becomes a pain for the eyes (and then becomes associated with the bland, same old same old just like under-illumination). That's why many movies may switch from scenes that are very dark to using normal lighting to some using over-illumination to keep the audience involved. Just a thought.--64.75.187.197 08:32, 16 May 2006 (UTC)

Very good insights, Just. you might find Lighting designer of interest, where the stage and cinematic effects of lighting are detailed. Anlace 12:10, 16 May 2006 (UTC)

[edit] Electricity wasted?

I point out that the article states energy is wasted by over-illumination, but this is not entirely true. As anyone who passed Grade 9 science can verify, the Law of Conservation of Mass states that in a chemical reaction, the mass of the reactants remain constant. (Slightly different scenario here, but the same idea). Electricity spent by light becomes mostly converted to heat (the ratio depends on the type of bulb used) which heats up the building. In summer this is a bad thing, but in winter lighting bulbs are almost 100% efficient since the excess heat reduces the heating bill. The small percent of electricity that becomes converted into light instead of heat is mostly converted into heat anyway once it strikes a non-absorbing material. Therefore the amount of energy "wasted" by over-illumination stated by the article is misleading. Dilbert 21:00, 18 May 2006 (UTC)

Two important points are missing from your analysis Dilbert:

1. The summer addition to heat a building is typically reversed by more energy to drive air conditioning, so counting summer and winter effects together there is no net benefit and in fact a further loss, because of real world thermal efficiency (laws of thermodynamics)
2. While the conversion of light to heat is nominally "efficient" in the sense that conversion is efficient, the real point is that the net expense of "heating" a space by light is absurdly uneconomical and wasteful because the electrical energy used is far greater than the energy required by conventional (for example, forced air or radiant) space heating, for example. Anlace 22:46, 18 May 2006 (UTC)

I concede your first point, which I already noted in my original paragraph. However, I must dispute your second point; using a bunch of lightbulbs versus using an conventional heater has the same efficiciency. "Efficiency" is measured by the percentage of electricity that goes towards the intended purpose, versus the percentage of electricity that is "wasted" or converted into heat. A device which converts energy into heat is always 100% efficient because its intended purpose is to generate heat. Dilbert 22:43, 20 May 2006 (UTC)

thanks for your continuing dialog. i acknowledge that you are technically correct about the conversion of electricity to heat. the real issue is how much energy does it take to provide a unit of space heating. central air systems are about 70 to 95 percent efficient, meaning per unit of natural gas consumed .70 to .95 of the natural gas thermal energy is recovered; whereas for electicity production from natural gas, conventional power plant boilers are about 34% efficient, meaning that per unit of natural gas consumed (to power that light bulb for heating) only .34 of the natural gas thermal energy is recovered as usable heat. the same argument would apply for oil or coal as primary fuel sources. thus use of a light bulb for heating (as is commonly known in the industry) is not an efficient use of primary fuel, although the last step of the thermal conversion (light to heat) is virtually 100% efficient. nevertheless while you lost the battle, you won the war, because ive removed the word wasteful where it occured in the article :) cheers, Anlace 01:31, 21 May 2006 (UTC)

Not entirely sure what the natural gas/oil/coal thingy meant but as long as it doesnt say "wasted". Thank you for your assistance. Dilbert 01:11, 27 May 2006 (UTC)

I think the point is that heating by lightbulb is exactly the same as heating by electric space heater, and heating by electric space heater is expensive and inefficient, and here's why: when you burn coal or natural gas to make electricity, the most efficient plants are only around 60% efficient at the energy conversion. So when you convert that electricity to heat in your house, you're only using at most 60% of the energy from the original fuel. But if you had just burned the natural gas in your furnace, you would get close to 100% of the energy from it as heat.Dreadengineer 20:17, 2 November 2007 (UTC)

On an unrelated note, I am deleting the sentence about lighting using millions of barrels of oil a year. The U.S. electric grid is powered by around 50% coal, 20% natural gas, 20% nuclear, 6% hydroelectric, and a few percent of miscellaneous things, which includes a few oil-burning plants in remote areas. I don't know where that oil-use information came from, but it can't be right since oil is such a small part of electricity generation.Dreadengineer 20:18, 2 November 2007 (UTC)

[edit] Reverts

Anlace, I reverted your revert. From your comment, I gather you feel I changed the meaning of some passages in a way that disagrees with what has been published. If so, feel free to fix whatever you feel was inappropriate, but don't simply do a blanket revert on the whole thing. Many of my changes (particularly to the introduction) do not change the meaning, but clarify what was there. --Srleffler 22:34, 27 May 2006 (UTC)

[edit] Circulatory and circadian rhythm effects

This entire article has serious neutrality issues, I think. But I'll just speak to this one. Humankind's origins are sometimes thought to have been in the African savannah. In any case, the "natural" habitat for humankind almost surely involves being out-of-doors much of the time. Even in the open shade under a tree, outdoor illumination is around 10,000 lux. In natural surroundings, the daytime light exposure of a human being would surely vary in the range of 10,000 to 100,000 lux (broad daylight), for periods of around 12 hours a day.

I think it is extraordinarily difficult to believe that indoor artificial light exposures during daylight hours could be causing the sort of harm that is suggested. Dpbsmith (talk) 00:51, 28 May 2006 (UTC)

The over-illumination phenomenon is clearly stated to include quality of light (e.g. spectra mismatches and flciker effects} as well as quantity of light.

1. One of the sentences in this section was added recently to acknowledge continuing research is needed to pinpoint which of these factors is most important in the health effects studies. primitive man of course didnt have to worry about light quality.
2. The health effects data speak for themselves. some of the research has been sponsored by lighting companies trying (unsuccessfully) to prove over-illumination isnt that bad. i have read the references cited herein and they are convincing. you are welcome to find or add other studies that you think may lead to other conclusions.
3. I just returned from the "cradle of civilization" you mention in the African savanna. it was very interesting to me to be led by native guides and be shown where they believed their ancestors lived: generally in caves within cliffs of the Waterberg and related upthrust formations. there are a variety of theories on their lifestyle, but much of the musing suggests they were smart enough to stay in the cave between 10 am and 4 pm. remember that most of the health effects data cited shows results to 8 or more continuous hrs of exposure to bright artificial light.Anlace 02:31, 28 May 2006 (UTC)

[edit] Wording

I'm still concerned about the wording of this section, particularly this paragraph:

Circadian rhythm disruption is an effect of too much light, too little light or incorrect spectral composition of light. This effect is driven by stimulus (or lack of stimulus) to the pineal gland, the body’s photometer, that thence signals the brain as to time of day. In total light deprivation or total darkness the body’s clock is thrown off, if the light condition persists for too long a time. The principal adverse outcome seems to arise from workers subject to intense fluorescent light, which is poorly matched to the spectrum of sunlight. The body translates this condition as total darkness and resets the circadian clock incorrectly. Not only does this result in fatigue, but also immuno-supressive behavior that has been shown to be linked to increased cancers. Bright light inhibits production of melatonin, a substance shown to reduce cardiac arrythmias and to reduce oxidized lipids in the ischemic heart. Melatonin also reduces superoxide production and myeloperoxide (an enzyme in neutrophils which produces hypochlorous acid) during ischemia-reperfusion.^{[1] [2]}. Whether these circadian impacts arise from too much fluorescent light or too little natural light may be a subject of future scientific inquiry.

Now, I'm not disputing the assertion that research shows that working under fluorescent light can cause circadian rhythm problems. I do wonder, though, to what extent the current wording accurately reflects that research. The way it is phrased makes statements that seem too strong to be a good scientific description of a research study.

For example, the claim that the body interprets intense fluorescent light as total darkness has a pseudoscientific feel to it. Such a strong statement would be justified only if the reseach has carefully compared the response of the body to total darkness, as well as varying levels of weak illumination, and found that the response of the body to fluorescent light only matches that to total darkness, rather than the response to weak illumination. Otherwise, if the study shows merely that working under fluorescent light has the same circadian rhythm effects as being in total darkness, the article should say that directly.

My other concern is that this paragraph seems to confuse issues of too much light and incorrect spectrum of light, despite the qualifier added at the end. It seems nonsensical to imply that too much fluorescent light (as opposed to too little natural light) is interpreted by the body as total darkness, in the absence (admitted by the qualifier at the end) of research explicitly showing that. Would you suppose that weaker fluorescent light would be better? i.e. that if you cut the fluorescent lighting intensity by half the workers would have fewer circadian problems even if they received no more natural light? More importantly, does the research suggest that this is the case? If not, it would be better to focus on the angle that excessive use of fluorescent light instead of natural light causes circadian rhythm problems. -Srleffler 15:13, 29 May 2006 (UTC)

Thanks for your thoughtful analysis. Had I not read each of these references, being a physicist, i would come to exactly the conclusions you have. now lets consider the "total darkness" sentence. The researchers themselves used that phrase to emphasize the surprising nature of this outcome. They did some control studies but not using every possible light intensity setting. I think your second point is the better one: how can we better state that its the ratio of natural light to fluorescent that seems key (this is the implication of most of the research, but most researchers really stop short of this conclusion itself). I am open to trying to articulate this better. I shall visit this section and attempt an edit. best regards Anlace 17:21, 29 May 2006 (UTC)

I think the "total darkness" statement should be specifically cited, i.e. it needs a reference tag identifying which researchers made this claim. If you need help with the tag, I can help. I'll take another look at the natural vs. fluorescent issue in that paragraph, given what you have said. --Srleffler 05:05, 5 June 2006 (UTC)

I think your edit is fine. I've looked at several of the references and couldnt find the quote yet on "darkness". You are creating a little bit of work for me. Do you know there are over 3000 studies relating circadian disorder to lighting ?? :} Best regards. Anlace 06:13, 5 June 2006 (UTC)

[edit] Terminology: Natural vs Day vs Sun -light

When referring to the light coming from the sun during the day, what should the the consensus on what to refer to it as. Day or sun work for me. The use of 'natural' light is excessive, unnecessary and biased, as it infers that man-made (artificial) light is not natural. The principle that humanity and it's creations are not natural goes against the scientific principle of naturalism as I'm sure many would agree... so day, or better probably sun, is more technical. Tyciol 07:01, 19 June 2006 (UTC)

sun is probably the best answer hereAnlace 14:49, 19 June 2006 (UTC)

[edit] Light pollution

It would be nice if there was a comparison or at least relationship established with light pollution. They seem like similar but distinct problems with a similar cause. Stevage 12:46, 23 June 2006 (UTC)

good point,especially as it is established in the otehr way (there is an Over-illumination section in light pollution). Circeus 14:35, 23 June 2006 (UTC)

i have attempted to define the major distinctions by adding a second paragraph to "numerical definition of over-illumination". the intro is already a bit long so i didnt place it there. see what you think as far as clarity. over-illumination is technically a subset of light pollution issues, but perhaps more importantly, over-illumination deals with issues within the property of the source of the light, whereas light pollution is generally concerned with trespass light extending beyond the property from which the light emanates. Anlace 14:56, 23 June 2006 (UTC)

[edit] Occupancy Sensors

I take issue with the lines "A 2005 survey of commercial buildings indicates that only about five percent of structures utilize any form of occupancy sensor, a device that has been available for over 15 years." and "Omitting occupancy sensors is an error..."

Anyone who has had to wave their arms around every 45 seconds--lest they be plunged into darkness--knows that these things are rarely practical. Perhaps someone has designed a better one (maybe combining motion detection, sound detection, and heat/infrared light detection?), but if they have I've never seen one in action. --Lode Runner 02:39, 13 February 2007 (UTC)

[edit] General critique

I see four general areas in which this article could focus on:

- Lighting unoccupied areas (energy waste) - Spectrum of ambient lighting and its effects on humans - Required levels of lux designs for various situations - General human tolerances of light

The first section is fairly straight forward. It is clearly a case of over illumination when an area is lit when no lighting is required. This can be tied in to energy efficiency and usage of power very succinctly. A prudent method of introducing this would be a discussion of floor wide ceiling light switches (though there are clearly beneficial reasons to be able to light an entire office area with one flick of the hand from one central location) , automatic timers, motion sensors etc. Currently this information is spread throughout the article and doesn't for a concrete section of over illumination.

The effects of the spectrum of ambient light is logically separate wholly and entirely from the lux levels of illumination. This is where a daylight spectrum vs artificial spectrum discussion should be confined. There are a number of instances of obscure spectral situations that humans a thrust into, generally sans health effects. For instance, submariners are in a situation of continuous artificial light for a duration of months, and a cursory scan produced no studies or reports detailing increased cardiovascular disease or some of the other symptoms mentioned as possible results of non-sunlight lighting. Perhaps a discussion of some military control rooms in which they are lit with red lights for the duration of 8 hour shifts could provide an intriguing aside in the discussion of light spectra. In addition, examples of polar researchers could be useful if they could detail harmful effects of sustained artificial illumination during polar night when natural sunlight is minimal at best.

The discussion of lux levels currently in the article seems to be unclearly melded with the spectral discussions. I would love to see some explanation why the incredible lux levels of sunlight are bad whereas the spectrum of it is good. Perhaps we need 100000 lux sunlight spectrum office lighting! This dichotomy needs a thorough scientific explanation. Why is 1000 lux too much in a retail store but is far to little for a farmers market held outside? This needs to be clearly addressed as it is a failing of the current explanation of over illumination.

Human physiology also should be explained. What are our eyes capable of discerning at different lux levels? How dim of lights is it possible to read by? What levels of lighting do people choose for various tasks? Why is a romantic dinner lit more dimly than an energetic party? In general, how is over-illumination a problem for humans in various situations and how to they adapt?

A great tangent to the discussion of human responses to lighting would be the situation of walking out of a dimly lit movie theater into a stunningly, blindingly bright noon sun. Perhaps there are instances where high levels of light are prudent to prevent the kind of light shock that can occur stepping into a blinding bright outdoors.

LucidlyLogical 03:03, 14 March 2007 (UTC)

thanks for your interest in this article and some good questions and ideas. i would advise caution on quick wholesale changes as this article has been crafted from a number of editors working together together to address many of the issues you have raised. and the existing version is a compromise that seems to have held up very stably for quite a while. some of your ideas (namely your latter topics) would make great subarticles. why dont you have at it in creating one of them. the trickiest part of your dialog relates to the intensity of natural light. the main issue here is: inadequacy of research data base of task work in sunlight (have you ever tried to write a computer program or use your computer screen in bright sunlight?). if you have specific ideas on a new table of contents, i would be glad to work with you, but you may be stirring up a hornets nest with others. best regards. Anlace 22:02, 16 March 2007 (UTC)

Anlace, great article! Being a colour consultant with lighting as one of my special interests, perhaps I may be permitted to butt into this discussion with an attempt at providing extra clarification for LucidlyLogical?

* Which luminance levels, light colour (= kelvin degrees), light quality, light direction and other lighting properties are optimal for each specific situation varies greatly depending on task, location, season, time of day, age & skin colour of user, personal preferences etc. Here are some general guidelines:

* The old recommendation - before the age of computers - was: the finer the task, the more light you need on that particular task - though too much light can be just as straining to the eye as too little, as this article already has described. Besides computer work (which we all know is dificult to impossible in sunlight), have you ever tried just reading a book or magazine in direct sunlight? Wasn't it terribly glaring and straining to your eye? Since most office work includes reading and/or computer work, this is why you can't have light as bright as sunlight indoors even though it works just fine when you're out playing, sporting, hunting or farming. Ref: Besides common sense, any professional lighting guidelines will likely confirm this.

Since more and more office work nowadays is done on phone and computer only, illumination levels could probably be cut in half or more, with only visual improvement as a reslut. In my professional opinion it should also be more directional (e.g. downlights; to avoid glare) for ambient lighting + individual desklights for specific offline tasks.

The brightly and evenly lit office with most of the light coming from ceiling tubes and stimulates the whole body is IMO an obsolete lighting model which is no longer suitable for modern offices - if it ever was. What is great for building construction, factory- and janitorial work is not necessarily as good for jobs where you're sitting down and need the body to be relaxed and only the head to be alert; bright light may easily be as overstimulating to a sitting body as large amounts of carbs (which is a great energy source for athletes and heavy manual labour but ofen way too much for a student or white collar worker). Another fact which tends to be forgotten is that computer screens are light sources in themselves.

* The older you are, the more light your eyes will need. A 60-yo eye may need up to 10 times more light than a child's in order to see as well. At the same time, the eye gets more sensitive to glare with age, due to accumulation of fine scratches on the lens which will produce more glare, just like sunlight will be more glaring when it hits an old, scratched car wind-shield than coming through a brand new glass. Ref: Belysning inomhus: riktlinjer och rekommendationer (Indoor lighting: guidelines and recommendations), Ljuskultur, Sweden, 1990.

* The less pigment you have in eyes and skin, the more sensitive you are likely to be to light in general and to UV light in particular. That one's forefathers possibly grew up under bright African sunlight, does not automatically mean one can well tolerate prolonged exposure to similar lighting levels now, if one happens to be a pale European type. Ref: Any modern public UV recommendation for various skin types.

* There are individual differences in preference, regardless of pigmentation. Some people have an innate or aquired preference for dimmer lighting than the majority and may feel stressed in brighter light. Ref: Veitch, J.A., PhD & Newsham, G.R., PhD (2000) “Preferred luminous conditions in open-plan offices: research and practice recommendations,” Lighting Res. Technol. 32 (4), 199-212.

In studies on what lighting conditions people prefer in offices, Veitch & Newsham, McGill University, Montreal, found that most would like to have windows, preferably with blinds or curtains, but that they wanted to have electric lighting too, and to be able to adjust both the position and the angle of the lighting and to turn the lights on and off during the day. Since the participants were very satisfied when allowed to adjust the lighting to suit their particular preference, and most of them chose luminance levels within current recommendations or lower, Veitch & Newsham recommend lighting solutions that are as flexible as possible, with dimmable lights, local switching and wiring that allows one to move things around. Ref: Veitch, J.A. & Newsham, G.R. (2000) “Exercised control, lighting choices, and energy use: an office simulation experiment,” Journal of Experimental Psychology 20, 219-237

Some are hypersensitive to fluorescent light and function best in natural daylight or incandescent light. Others can tolerate FL but are not overly fond of it, while some even prefer FL to other types of light. Some prefer warmer light, others feel best in cool light. Ref: various sources, including personal interviews.

* Psychological effects of different lighting designs: The cooler, the brighter & more evenly distributed the light and the higher up it is placed or directed to, the more stark & impersonal the effect. The warmer, the dimmer and the more concentrated the light and the lower down in the room it is placed or directed to, the more intimate & sophisticated the atmosphere. This is why more exclusive restaurants, hotels, boutiques, car showrooms etc, usually are very dimly lit, with mainly incandescent directional light. And this is why a candle-lit dinner is more romantic than eating under bright, cool fluorescent tubes. Ref: Starby, L. ”Ljus i butik” (”Shop lighting”), Ljuskultur 3/95 & 4/95 + personal & professional experience. Lorielle 03:13, 21 September 2007

[edit] Causes

"While the energy wastage effect is notable, the health consequences are of greater significance, because numerous studies have shown the importance of matching the color spectrum of sunlight when illuminating the workplace."

The above is in the 2nd paragraph of Causes. However it's clearly talking about effects (it even uses the word). I would just delete it from this section except I don't know what to do with the references immediately after it; whether they apply to this sentence or the whole paragraph. My guess is that the latter two of the three references apply to this sentence and could be deleted with it.

JRocketeer 00:19, 21 March 2007 (UTC)

Thanks for not just erasing some important context and references! I have moved this text block and copy edited for its new placement. This is one of several problems I am still mopping up from another editor's changes many months ago, where new section headings were created (by another) without proper editing material i had produced. Anlace 02:07, 21 March 2007 (UTC)

[edit] Fluorescent Lamp Wearout

The article fails to acknowledge that fluorescent bulbs tend to be vulnerable to wearing out faster if they are turned on and off frequently. In some cases, they may wear out very fast. So, it is a challenge to use them appropriately to save energy, in situations where light is only needed for a few minutes. (It is misleading to only mention startup inrush current, under the guise of dispelling a myth. Premature failure of lamps is not trivial or irrelevant.)-69.87.193.242 13:16, 4 April 2007 (UTC)

Surprising to see how this myth of wearing out bulbs is perpetuated. The scientific literature is clear on this point. Bulb wear out is not significantly exaggerated by turning off fluoroescent bulbs if they are not in use for say five minutes or more. The only challenge here is educating the general public that this mythical wear-out is not an issue. Anlace 19:18, 4 April 2007 (UTC)

[edit] Sleeping with the lights on

Mention people who like sleep with the lights on. Fear of the dark, or some circadian rhythm related thing? Jidanni 16:20, 19 July 2007 (UTC)

[edit] broken link

The link to the last reference, "Dispelling the myth of leaving lights on", doesn't work. I can't find that document on the web either. I don't know what to do in this situation, so somebody please remove the reference from the text.

Raichu2 04:29, 18 September 2007 (UTC)

[edit] Wasted oil reference

The article states, without reference that "The total worldwide energy wastage from over-illumination is roughly 1.5 billion barrels of oil per annum". The calculation from the Light pollution article is only around 700 million barrels of oil, and even that calculation is not justified by a reference (it is not clear that all the assumptions that go into the steps of the calculation are justified and a number of steps lack references...one might even say that series of calculations is Original research). Perhaps the 1.5 billion number came from the "alternate calculation" where the Light pollution authors stated that four-five million barrels of oil equivalent are used to light buildings; this comes to about 1.5 billion barrels per year. However, clearly not all the energy used in lighting is wasted which brings the "wasted" number back down around 700 million barrels. And still, this number has no direct reference. I have added a {{Fact}} tag and will remove the statement in a couple days if no one provides a verifiable explanation or explicit reference. Bjp716 (talk) 00:06, 19 January 2008 (UTC)