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Study: LED lighting hazardous to public health


HAIFA, ISRAEL – A new international study has found that exposure to white LED bulbs is significantly more harmful to public health than exposure to the orange-yellow light emitted by high pressure sodium bulbs.

The findings by a team of researchers from Israel, Italy and the United States, in a study titled “Limiting the impact of light pollution on human health, environment and stellar visibility” by Fabio Falchi, Pierantonio Cinzano, Christopher D. Elvidge, David M. Keith and Abraham Haim.were recently published in the Journal of Environmental Management.

“White” light, the researchers found emits light at shorter wave lengths (of between 440-500 nanometers) and suppresses the body’s production of melatonin five times more than exposure to orange light.

Orange-yellow light is primarily used for outdoor illumination, such as street lights, road lighting, and mall lighting.

Melatonin is a compound produced in the brain’s pineal gland. It is responsible for regulating the biological clock in humans and animals and is known for its anti-oxidant and anti-cancerous properties.

The landmark study was conducted by astronomers, physicists and biologists from Italy’s ISTIL- Light Polution Science and Technology Institute in Italy, the National Geophysical Data Center in Boulder, Colorado, and the University of Haifa.

Researchers examined different levels of melatonin suppression in various types of light bulbs and recommended measures to save energy and protect public health.

The metal halide bulb which emits a white light and is used for stadium lighting suppresses melatonin at more than three times that of the HPS (high pressure sodium) bulb.

The light-emitting diode (LED) bulb, which also emits a white light, they found, suppresses melatonin at more than five times the HPS bulb.

“Just as there are regulations and standards for ‘classic’ pollutants, there should also be regulations and rules for pollution stemming from artificial light at night,” Professor Abraham Haim, head of the Center for Interdisciplinary Chronobiological Research at the University of Haifa.

White light should be used where absolutely necessary, the researchers recommend. Lamp posts should be adjusted so that their light is not directed beyond the horizon to reduce light pollution. Lights can also be simply switched off when not in use to reduce “over-lighting” and save energy.

Most Italian regions have legislation to lower the impact of light pollution, but lack regulation on the spectrum emitted by lamps, says ISTIL’s Fabio Falchi.

“Unless legislation is updated soon, with the current trend toward white LEDs which emit a huge amount of blue light, we will enter a period of elevated negative effects of light at night on human health and environment. Lamp manufacturers cannot claim that they don’t know about the consequences of artificial light at night.”

“In Israel the Standards Institute should obligate bulb importers to state clearly on their packaging the wavelengths produced by each bulb. This information needs to be brought to the public’s attention, so that consumers can decide whether to buy this lighting or not,” Prof. Haim says.


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Yehonathan Tommer Posted by on Sep 11 2011. Filed under Community, Health, More News, Sci-Tech, World. You can follow any responses to this entry through the RSS 2.0. You can leave a response or trackback to this entry

9 Comments for “Study: LED lighting hazardous to public health”

  1. There are plenty of web-sites relating to melatonin suppression in humans. Just Google it out. It is an established fact.

    Outdoor lighting is a serious environmental problem that has long since been neglected, largely because of municipal and commercial interests exploiting public fears of crime and security. The fact that crime is not reduced by lighting does not seem to register. Most crime of the kind we fear occurs in daylight, ergo criminals need light. Lighting extends daylight, so people will behave at night more as they would during the day, consequently our most crime infested areas are also the most intensively lit. Economic constraints have caused some municipalities to introduce curfews on lighting, and where this has happened crime levels have gone down by as much as fifty percent. It has also been reported that crime levels drop almost to zero during power failures.

    We don’t need most of this lighting and it could be cut back by as much as 80% without significant loss of amenity. Of course some lighting in city centres will be necessary where a twenty-four hour society prevails, but it should meet certain standards.

    Lighting should only be applied sparingly, on a needs must basis, where needed, when needed, in the correct amounts, using appropriate 45 degree full cut-off technology. It should not be applied in rural areas, and its application in suburban and residential areas subject to an 11p.m. till dawn curfew. There are plenty of methods available to improve road safety without naive recourse to lighting.

    The environmental effects of night-time lighting are now well established. It is wasting money and contributing to climate change. Of all the environmental problems facing the world today, this is the easiest to solve by switching off lighting when not needed, and removing that which is not necessary. The frivolous abuse of lighting, such as floodlit buildings, skybeams, lasers and other art follies should not be tolerated. The latter are often installed under the pretext of regenerating depressed areas, to promote commercial interests, and by incompetent elected officials on an ego trip. Sports facilities should be roofed over, or sports enthusiasts encouraged to confine their activities to daylight.

    The money saved by cutting back on unnecessary lighting can then be redeployed on areas that really do matter, such as health, education, welfare, and state pensions.

  2. The “hidden” harm caused by the light pollution created by the modern 24 hour day is simply ignored.
    Why? It costs millions – permanently loses the dark nocturnal habitat required by insects and bats etc and the millions it wastes could pay for health and hospitals. Is this GOOD?

  3. This article is incomplete. Please cite the complete research source. One may expect that surpressed Metatonin levels may help keep sleepy drivers awake, possible reducing accidents. A double blind study of say 200km of HPS illuminated roads Vs 200Km of LED illuminated roads would be interesting to see. Of course good design for low glare and uniform lighting is always needed what ever the source used. Keeping all light away from bedroom windows is also important,

  4. What was the CCT, CRI and R9 values of the LEDs that were used in the study? If they are identified, what melatonin response was there to the different values?

  5. This study is not about LEDs at all. It shows that the body’s response to white light is different to its response to orange light. But most electric light is white, whether it comes from fluorescent or HID bulbs, and this study does not have any reason to single out LEDs as being any worse than any other white light source. But somehow all the journalists are reading this non-existent conclusion from the academic study. Perhaps the journalists have an urge to scare the public about things that are new.

  6. This is interesting but the question become how relevant it is. It only becomes important if the melatonin is suppressed during the sleep cycles. The study done by the Lighting Research Center shows this is not the case. Their study can b e found at http://www.lrc.rpi.edu/resources/newsroom/pr_story.asp?id=210.

  7. This article is terribly incorrect and appears to be written by someone who knows nothing about lighting. The title alone is disturbing, “LED lighting hazardous to public health”… LEDs are everywhere. In what way are they hazardous? Is the author proposing that ALL LEDs are hazardous in every use? White light LEDs produce different amounts of blue light depending on how they are made, and yes some white light sources will suppress melatonin at certain light levels, after a certain duration of exposure… but to make the leap that suppressing melatonin is hazardous is proposterous. And to assume that anyone would look at an outdoor streetlight close enough, and for long enough to suppress melatonin is nearly impossible.
    Someone should quarantine Yehonathan Tommer with some white light sources until he or she learns how to research an article before publishing.

  8. Wavelength is inversely proportional to color temperature, which the article does not mention. Since most LEDs for commercial and residential use are treated with phosphors to create warmer light (low color temperature), it’s unfair to make the blanket statement that LED lighting is hazardous to public health. This smacks of the Tea Party fear-mongering about the lighting efficiency standards.

  9. What proof is their that Melatonin Levels were surpressed? Was it a human study?. Was it a plant study?

    Bill Hein

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