LEDs....and the health risks

[Kgirl]

Light and human health: LED risks highlighted

15 Nov 2010 LED Magazine - Tim Whitaker

Issues relating to the effects on health and well-being of artificial light are discussed in three recent publications; including one that says the blue-light component in white LEDs causes toxic stress to the retina.

It is now accepted that artificial night-time lighting has various effects on humans (not to mention wildlife) and that exposure to optical radiation affects human physiology and behavior, both directly and indirectly. Many areas are not well understood, and a position statement from the Illumination Engineering Society (IES) emphasizes mainly the need for further research. At the other end of the scale, a French government report emphasizes the risks of LED lighting and makes various recommendations.

IES position statement and DOE white paper

The Illumination Engineering Society (IES) has released a position statement entitled "Effects of Exterior Lighting on Human Health (PS-03-10)," which is not specific to LEDs. The document states that "optical radiation detected by the retina impacts an individual’s behavior, psychology, and perception of the environment. The position of the IES is to promote and encourage a more complete understanding of human responses to optical radiation leading to improved designs for all lighted environments."

The way to achieve this, says IES, is through additional research with specific emphasis on additional field research to document typical exposures to optical radiation in exterior settings. The document also states that "the position of the IES is that typical exposures to exterior lighting after sunset have not been shown to lead to cancer or other life-threatening conditions."

Meanwhile, the DOE Solid-State Lighting program has produced a White Paper entitled "Light at Night: The Latest Science," which resulted from a panel session at the SSL Market Introduction workshop held in July 2010.

The white paper concludes that, given the available research, it is unclear what changes, if any, should be made to current best-practice lighting design. "It is clear that additional peer-reviewed research and validation are required to determine the relative significance of the visual and the photo-neural effects of typical light exposures," says the report.

ANSES highlights risks from LED lighting

ANSES, the French Agency for Food, Environmental and Occupational Health & Safety, has published a report entitled (in English): " Lighting systems using light-emitting diodes: health issues to be considered," which focuses squarely on potential problems caused by LED lighting.

The full report is available in French only, but the report summary (in English) says that risks have been identified concerning the use of certain LED lamps, raising potential health concerns for the general population and professionals. "The issues of most concern identified by the Agency concern the eye due to the toxic effect of blue light and the risk of glare," says the report, adding that the blue light necessary to obtain white LEDs causes "toxic stress" to the retina.

Blue light causes a photochemical risk to the eye, says the report, the level of which depends on the accumulated dose of blue light to which the person has been exposed, which is generally the result of low-intensity exposure repeated over long periods. "Blue light is…recognized as being harmful and dangerous for the retina, as a result of cellular oxidative stress," says the report, adding that 3 groups are particularly at risk; children, populations which are already light-sensitive, and workers likely to be exposed to high-intensity lighting.

The other main risk is from glare. The report say that, for indoor lighting, it is generally agreed that luminance higher than 10,000 cd/m² causes visual discomfort whatever the position of the lighting unit in the field of vision. Because the emission surfaces of LEDs are highly-concentrated point sources, the luminance of each individual source can be 1000 times higher than the discomfort level. The level of direct radiation from this type of source can therefore easily exceed the level of visual discomfort. Other risks related to the use of LED lighting systems have also been raised, but futher study is required.

The report says that the photobiological safety standard (EN 62471) seems ill-adapted to lighting systems using LEDs, and that the Unified Glaring Rate used for the other types of lighting is unsuitable for LEDs. Among various recommendations, ANSES says that only LEDs falling into risk groups similar to those of traditional lighting systems be available to the general public, and that the highest risk lighting systems be reserved for professional use under conditions in which it is possible to guarantee the safety of workers.

Manufacturers and integrators of lighting systems using LEDs are encouraged to use optics or diffusers, for example, so that the beams of light emitted by the LEDs cannot be seen directly, to avoid glare. Manufacturers should also take account of the progressive wear of layers of phosphor in white LEDs, which in time could lead to devices being moved from one photobiological risk group to a higher one, according to ANSES.

[Brian]

well well, I wonder how long it will LED guys on here to claim this is all lies?

[YYZ]

well well, I wonder how long it will LED guys on here to claim this is all lies?

What lies?

The IES paper starts by saying that their report is not about LED lighting specifically, but all lighting - and that lighting can effect your health. Umm, if I recall correctly this is something that was stated here and some posters thought it was complete hooey. All lighting, remember.

From there, the French Food Agency report gets into LEDs specifically and talk about 'certain lamps' and how blue-ish LEDs can cause photochemical risk when exposed for too long, or for glare (ooh, deadly glare!). They then comment about how exposed LEDs can be too bright for safety - this is already known (ie: their Class 2 laser designation) and recommend optics and diffusers. They're basically saying 'don't look directly into the light'.

Problem solved by A) using warmer color tones and B) preventing direct view or glare with optics and diffusers. It's a simple article and the second part - concerns brought up by a food agency no less - are easily remedied by someone who knows lighting.

Edited November 16, 2010 by YYZ

[Brian]

hmmmm

Edited November 16, 2010 by chubbygumby

[YYZ]

see.....

See what - that you're creating a straw man to argue with? Did anyone claim any lies?

How about you tell us what you think the article says. Is it something in the first report from the IES, or the second report from the French Food Agency? Is there something in there that needs to be answered for? Please be specific.

[Brian]

look at my post again marko...

so there is no blue light in your white LEDs?

Edited November 16, 2010 by chubbygumby

[YYZ]

look at my post again marko...

so there is no blue light in your white LEDs?

Perhaps if you'd make a clear point, I could respond with a clear answer.

Yes - blue chips are used to create a white light. The issue of 'blue light' has to do with the emitted color, so when you see lighting systems with LEDs (or other light sources) that are between say, 8000-10000K, or actual Blue lights, over-exposure can cause damage similar to looking directly at a lunar eclipse. First off, they don't make any mention of how much exposure is needed, nor do they state that there is any evidence of this being a problem - only something that is a possible concern. Using quality LEDs in the right color spectrums makes this concern moot, but you wouldn't expect the FDA to know necessarily that in the US either, right?

Further, it doesn't take a genius to know that looking directly at any intense light is not good for your eyes. This is not something unique to LEDs, but since it was posted on an LED website it was brought up as something to watch out for. If it was a welding website and they mentioned that you had to watch out for flash burn, is somebody supposed to come out and say it's a lie?

I don't know what you're looking for here... ?

[Brian]

I not looking to argue with you marko you take everything personally why?

I made a clear point does your leds contain blue light. I said nothing more, or did not make any claims for or against leds or any other light source.

I am though tired of your continual personal attacks of me on this site. Can you please just discuss the revelant points in posts without attacking me?

Not one time in this post did I mention you or your LEDs, but you came back with rude comments aimed right at me.

Grow up please.

[Erik Sine]

Brian, Marko's not being personal with you here on this thread.

Your first post was

well well, I wonder how long it will LED guys on here to claim this is all lies?

I don't know how many other LED guys on here who post openly and speak from experience other than Marko & Manuel, all the others just read with a zero post count. So I don't even know who else is going to respond to your accusation of "LEDs guys" are going to call this report a "lie", other than them. So in a indirect way, you're calling them out, one of two. One's answering you.

I think Marko gave a pretty good explanation and his own interpretation of what the article from the LED magazine is relaying, whether it's true or not.

You have me lost. If someone first said "it's a lie, it's not true" and had no explanation then there's something to be looked at here or countered with facts, but so far no ones disputing light affect living conditions, LED or other.

[YYZ]

Thanks Erik - I was at a loss to understand what I said that was a personal attack?

Brian - you asked for an LED person to chime in (assuming the article said something damaging to begin with), and I did. The reply to that was "see....", which is hardly a clear point at all. I asked you to be specific about what you thought needed to be responded to - so you went back and edited a question into your previous post.

In my next reply I thought I was answering the relevant points (to the question added). It was specifically asked if our LEDs (or any) had blue light in them which I answered, and you chose to construe that as a personal attack?

Anyways - forgetting all that - I'm trying to understand what the problem is with having blue light within LEDs? Are you saying that any light source that converts blue light to white supposed to be a health risk?

[Brian]

Thanks Erik - I was at a loss to understand what I said that was a personal attack?

Brian - you asked for an LED person to chime in (assuming the article said something damaging to begin with), and I did. The reply to that was "see....", which is hardly a clear point at all. I asked you to be specific about what you thought needed to be responded to - so you went back and edited a question into your previous post.

In my next reply I thought I was answering the relevant points (to the question added). It was specifically asked if our LEDs (or any) had blue light in them which I answered, and you chose to construe that as a personal attack?

Anyways - forgetting all that - I'm trying to understand what the problem is with having blue light within LEDs? Are you saying that any light source that converts blue light to white supposed to be a health risk?

changed my mind.... walking away

Edited November 17, 2010 by chubbygumby

[YYZ]

To follow up...

Fluorescents and neon also use phosphors to convert blue light to white, so as those products break down, there would be a similar risk of exposure to blue light - perhaps greater with fluorescent considering their shorter life cycle and the number of times they reach break-down stage. Considering how many millions of fluorescent tubes are out there, I would think this would be a far larger safety concern. It's why they recommend those little plastic shades when you get into a tanning booth, for example.

In regards to intense light being potentially damaging, that's pretty widely known by everyone - hence my comment about not needing to be a genius to know that (that wasn't directed at anyone personally, it was a rhetorical comment). Any high intensity light source can cause retinal damage, regardless of color or type of emitting source. I've had flash burn from welding so I've experienced it first hand.

In regards to LEDs Magazine - for anyone who doesn't know much about it - it's mostly a news aggregator type thing. Anything and everything related to LEDs gets linked or posted and it's up to readers to filter out what they deem worthwhile. It's not some industry approved source of verified info, and is not much different than other trade mags who accept submissions and/or press releases from people in the industry. It's a great site to have bookmarked if you want to hear about what's going on, though very, very little of it is sign or display related.

[manuellynch]

Hell - send me the link to the article in French. I read French. I know Tim Whitaker - I will get it from him.

Blue light has both positive and negative effects on humans. Really depends on the peak wavelengths. Most phosphors out there do not adequately address this issue brought up in the French report. Nichia has mastered the art of recreating a spectral distribution of white light from a blue LED source that is very similar to other light forms - hell...they should...they make phosphors for fluorescent and neon as well!

So no lies....this is a common issue with all lighting that is "down converted" from one color to another.

And I do agree with the article - some people do not respond well to neon, some horrible to fluorescent, some people adore and yet others hate LEDs...preference folks.

Please note that Fluorescent and neon actually is UV light being downconverted to white - I think we all know that UV is not that good for us....but then again in New Zealand an article just came out telling people to go out and get more sun and more UV!!!

I think the biggest health risk of any lighting is reading all of this!!!! hahaha...like the labels on alcohol bottles in the USA - only in the USA...nowhere else...and we are perhaps one of the smallest consumers of alcohol in the world!