From the “law of unintended consequences” department comes this finding, suggesting that the push for eco-friendly energy savings may be doing more harm to us than good.
Study links night exposure to blue light with breast and prostate cancer
Researchers used images taken by astronauts to evaluate outdoor lighting in Madrid and Barcelona
A study performed by an international team led by the Barcelona Institute for Global Health (ISGlobal), a centre supported by the “la Caixa” Foundation, reports a link between exposure to blue light at night and higher risk of developing breast and prostate cancer. Blue light is a range of the visible light spectrum emitted by most white LEDs and many tablet and phone screens. The results have been published in Environmental Health Perspectives.
“WHO’s International Agency for Research on Cancer (IARC) has classified night shift work as probably carcinogenic to humans. There is evidence pointing to an association between exposure to artificial light at night, disruption of the circadian rhythm, and breast and prostate cancers. With this study we sought to determine whether night exposure to light in cities can affect the development of these two types of cancer”, explains Manolis Kogevinas, ISGlobal researcher and coordinator of the study. “We know that depending on its intensity and wave length, artificial light, particularly in the blue spectrum, can decrease melatonin production and secretion”, says Martin Aubé, physics professor at CÉGEP in Sherbrooke, Canada and study co-author.
The study was conducted within the framework of the MCC-Spain project cofunded by the ‘Consorcio de Investigación Biomédica en Red de Epidemiología y Salud Pública’ (CIBERESP), and includes medical and epidemiological data of more than 4,000 people between 20 and 85 years of age in 11 Spanish regions. Indoor exposure to artificial light was determined through personal questionnaires, while outdoor levels of artificial light were evaluated for Madrid and Barcelona, based on nocturnal images taken by astronauts aboard the International Space Station.
Results obtained for both cities show that participants exposed to higher levels of blue light had a 1.5 and 2-fold higher risk of developing breast and prostate cancer, respectively, as compared to the less-exposed population.
Ariadna García, ISGlobal researcher and first author of the study, says: “Given the ubiquity of artificial light at night, determining whether it increases or not the risk of cancer is a public health issue”. At this point, further studies should include more individual data using for instance light sensors that allow measuring indoor light levels. It would also be important to do this kind of research in young people that extensively use blue light emitting screens”.
“Currently, the images taken by the astronauts on the Space Station are our only way of determining the colour of outdoor lighting at a large scale, and the spread of blue light-emitting white LEDs in our cities”, comments Alejandro Sánchez de Miguel, scientist at the Astrophysics Institute in Andalucía-CSIC and Exeter University.
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Reference
Garcia-Saenz A., Sánchez de Miguel A., Espinosa A., Valentín A., Aragonés N., Llorca J., Amiano P., Martín Sánchez V., Guevara M., Capelo R., Tardón A., Peiró-Pérez R., Jiménez-Moleón JJ., Roca-Barceló A., Pérez-Gómez B., Dierssen-Sotos T., Fernández-Villa T., Moreno-Iribas C., Moreno V., García-Pérez J., Castaño-Vinyals G., Pollán M., Aubé M., Kogevinas M. Evaluating the association between artificial light-at-night exposure and breast and prostate cancer risk in Spain (MCC-Spain study). April 2018. DOI:10.1289/EHP1837. Environmental Health Perspectives
The full study is here: https://ehp.niehs.nih.gov/EHP1837/
I did some research into this.
There’s a Harvard study on night light, and in particular blue light.
But we may be paying a price for basking in all that light. At night, light throws the body’s biological clock—the circadian rhythm—out of whack. Sleep suffers. Worse, research shows that it may contribute to the causation of cancer, diabetes, heart disease, and obesity.
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While light of any kind can suppress the secretion of melatonin, blue light at night does so more powerfully. Harvard researchers and their colleagues conducted an experiment comparing the effects of 6.5 hours of exposure to blue light to exposure to green light of comparable brightness. The blue light suppressed melatonin for about twice as long as the green light and shifted circadian rhythms by twice as much (3 hours vs. 1.5 hours).
In another study of blue light, researchers at the University of Toronto compared the melatonin levels of people exposed to bright indoor light who were wearing blue-light–blocking goggles to people exposed to regular dim light without wearing goggles. The fact that the levels of the hormone were about the same in the two groups strengthens the hypothesis that blue light is a potent suppressor of melatonin.
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If blue light does have adverse health effects, then environmental concerns, and the quest for energy-efficient lighting, could be at odds with personal health. Those curlicue compact fluorescent lightbulbs and LED lights are much more energy-efficient than the old-fashioned incandescent lightbulbs we grew up with. But they also tend to produce more blue light.
See: https://www.health.harvard.edu/staying-healthy/blue-light-has-a-dark-side
So it appears that a nighttime blue light component equals less sleep and therefore more stress on the body. With more stress, then susceptibility to cancer increases.
I don’t know how accurate the methodologies in these studies are, but one thing is for sure, many white LED’s tend to have a larger blue light component:
Have a look at the CREE guide to LED color mixing.
In cool white LED’s, the two colors (blue and yellow) mix to create a white. This is shown below on the CIE 1931 color space:
Note: about 15 minutes after publication, reference to the Harvard medical study was added.
I work with light a lot, lasers and LEDs, and I have studied extensively the biological effects. The entire subject is much more complicated than what is presented here. There are numerous mechanisms where light is known to influence human physiology, both good and bad effects. The spectrum of various light sources vary enormously, even lights that look similar to the eye. Some, like fluorescent, have a very large spike in the blue spectrum balanced by low energy broad range of red and yellow. Some of the modern LEDs have a spectrum almost indistinguishable from solar. Some LEDs have a spectrum almost the same as fluorescent. If it appears bluish-white, it has too much blue.
Biological effects of light are well documented: ATP production increase, melatonin decrease, catalase and SOD suppression, nitric oxide, cytokines, immune function, influences on fertility, cancer, bone growth, wound healing, brain function, alzheimers, burn healing, macular degeneration, a very long list. If you doubt it, go to pubmed and search.
Can blue light cause cancer? Maybe. Anything that throws the regulatory system out of whack could possibly do that. Catalase and SOD in particular could be a bad influence. Blue light certainly alters stress response and sleep patterns. I agree that measuring blue light from space is a bad idea, since it doesn’t reflect well off typical urban surfaces.
However, there are strong influences not considered here. Most people don’t get nearly enough UV light, needed to produce vitamin D and melanin. We are constantly told to use sunscreen and wear UV blocking glasses. This probably causes more cancer than blue light LEDs, as well as suppressing immune function for more common diseases.
So be doubtful and ignorant about blue light if you want. If you really care, study the science. I use f.lux or isis programs to turn down blue light on my computers, and I use UV and infrared light every day to promote health. I found good LED lights from “Greenlite” brand, cheap at Ace Hardware, nearly the same as solar. Rely on natural light as much as is convenient, get some sun, avoid staying up too late and sleeping during the day. Some facts and common sense could change your life.
At my age just pour another G & T and relax. The damage is already done and you are living with it.
I think G&T comes under the common sense category. And bending your elbow does count as exercise.
I would add that you don’t have to resign to living with it. You can use infrared light to feel much better. 750-900nm light penetrates tissue well, relieves inflammation, promotes healing. Even in us old guys. I’m in my 60s and feel as good as 40s most of the time. I have an old injury in shoulder that makes it useless if I don’t use infrared. My older brother uses it for arthritis, better results than Rx. And it has been shown in studies to reduce alzheimers symptoms in about 80% of cases. Most returned to fairly normal life after treatment. It has even been shown to improve outcomes in heart attack and stroke.
Search pubmed for “LLLT OR photobiomodulation” plus condition, thousands of studies.
https://www.ncbi.nlm.nih.gov/pubmed/?term=LLLT+OR+photobiomodulation
Thank you Kent. And Vitamin D could be thrown off by wireless technology by interfering with the VDR Receptor: https://www.ncbi.nlm.nih.gov/pubmed/27412293 I doubt the issue of health effects from non-ionizing radiation will be popular to post about though – the good or the bad in it. I too use blue light goggles towards evening and try to get out in the sun to keep my clock “on”.
Vitamin D deficiency causes breast cancer:
https://www.grassrootshealth.net/project/breast-cancer-prevention
Vitamin D deficiency causes prostate cancer:
https://www.acs.org/content/acs/en/pressroom/newsreleases/2015/march/vitamin-d-may-keep-low-grade-prostate-cancer-from-becoming-aggressive.html
RDA for Vitamin D is wrong:
http://blogs.creighton.edu/heaney/2015/02/13/the-iom-miscalculated-its-rda-for-vitamin-d/
Well, astronomers will be very happy with this “study”. They hate those confounded LEDs ’cause they block out the stars. Maybe this is an attempt to link the lights to cancer so that they can have a reason to get rid of them? Prolly not, but who really knows?
Yet another GIGO ( garbage in, garbage out} computer model reported as fact.
My prostate has never seen the light of day, nor has my bile duct – until my cancer surgery.
If there were a CO2 angle in this study it would be about baby animals like polar bears or baby deer.
So maybe we would be better off if all forms of artificial lighting were banned. Certainly banning all forms of artificial lighting would help to reduce carbon pollution from the burning of fossil fuels.
From the early, early mornin’ till the early, early night
You can see miss Molly rockin’ at the house of blue light.
Good golly, miss Molly, sure like to ball.
When you’re rockin’ and a rollin’ can’t hear your momma call.
Just nonsense. The positives far outweigh the negatives. If I were Spanish, I would sell my shares in La Caixa for funding this study. Obviously they’ve been captured by fear-mongers.
And if it does at all bother you, wear a hat or live in the dark.
I’m not sure any of this matters. Remember how power lines were bad until we needed a million miles of them for wind and solar? Anything can go from bad to irrelevant in a heartbeat if it suits the current storyline.
‘Results obtained for both cities show that participants exposed to higher levels of blue light had a 1.5 and 2-fold higher risk of developing breast and prostate cancer, respectively, as compared to the less-exposed population.’
Note the hyped math: ‘2-fold higher risk’ in a small population. Easily explained as noise. Beware any study that says higher risk without giving actual numbers, from X to Y. 2x tells us nothing.
The cynic in me says they have bottomed out. They publish this because they have no path forward. If they had a path forward, they’d keep working on it til they had better data, and a real story to tell.
The Harvard study says:” At night, light throws the body’s biological clock—the circadian rhythm—out of whack. Sleep suffers.”
Apparently several pints at your favorite pub can counteract the disruption of your biological clock due to light. Perhaps a nice grant to study this would be appropriate. Who wants to volunteer?
Whenever I see something say “x is linked to y”, I know it is meaningless. The word “linked” has no scientific meaning and is only used when the results are so weak they can’t even say with the straight face that the two things are correlated, let alone claim causation.
Remember – no consequence is too great to save the planet – particularly if it also helps weed out those hominid despoilers.
Whether this cancer-link has any legitimacy or not is almost irrelevant – what’s ironic is how this sort of thing will be brushed over, while the slightest concern involving any targeted power source is sufficient to shut down entire industries.
The sort of ‘concern’ that one wears on their sleeve.
I just could not read the article, because the premise of isolating blue light (apart from all other factors) as a cause of cancer seemed too far fetched — to the point of being absurd.
Am I being too hasty, or did anybody else have this immediate first impression?
I’d like to see a study includes actual measurements of subjects’ estrogen and testosterone levels, hormones that do feed breast and prostate cancers. If blue light down regulates melatonin, might there be an offsetting up regulation of these sex hormones?
Silly to blame the LED light when it’s the unnatural night-time work causing the stress.
The average age of the women in the study with breast cancer was 55.8 (s.d. 11.9). For the men with prostate cancer it was 65.1 (s.d. 6.8). Note that this was their age at the time they were interviewed for their exposure histories, NOT their age at first diagnosis.
So it’s also silly to blame LED when a large number of these people first developed cancer long before they ever saw their first LED light bulb of any kind, never mind significant amounts of LED outdoor lighting.
Final note: participants over 40 years of age were asked to estimate their indoor, nighttime exposure level at age 40. For many of them that would have been 30 or 40 years prior. The Likert scale categories were: total darkness; almost dark; dim light and quite illuminated. The study further states that no further definition of these categories was provided. That’s a pretty good leap from “dim” to “quite illuminated.” It seems likely to have biased the numbers toward the highest category.
You realize that manufacturers of LEDs can alter the LED’s emissions spectrum, don’t you.
Wow, the most cynical comment thread ever! lol
Flashing blue lights in my rear view mirror causes a spike in my heart rate and blood pressure as well as anxiety.
On a more serious note. The old ‘yellowish’ street lights of 50 years ago attracted swarms of insects that attracted bats. The lights changed and the bugs and bats disappeared.
That is another reason I still have a house full of incandescent lights. Threw all my CFL lights out years ago when one exploded in the washroom, and never even went for the LED .
Please keep up this particular scare – when the ghastly eco bulbs were forced in by legislation in the U.K. I bought several hundred incandescent tungsten bulbs for a few pounds on the last day shops were still allowed to sell them. I still have a large stock and look forward to selling some at senseless and extortionate prices if people become terrified of contracting cancer from LEDs.
Sound cynical ? I suppose so but small beer compared to the much more cynical climate terrorism visited on us all.
I remember going to Target shortly before the (effective) ban on traditional incandescents and loading up on light bulbs. There was another man in the aisle doing the same thing. I wish I could remember his exact comment, but it was something to the effect of “thanks a lot, damn light commies”. (In a suburb of D.C.!)
There were no more old-school incandescent bulbs left when we walked away from that aisle. And I was very sad when I finally ran out of those bulbs and had to shell out a small fortune for the lower quality “eco-friendly” bulbs.
Are the observed effects due to higher blue light levels OR lower red/green light levels?
Are they even observations at all, or just made up stuff like the glysophate “study”?
Amusing that the ‘NASA’ caption indicates “many sections of the city use mercury vapor lamps (orangish)” which is obviously false. Mercury vapor lamps have a strong blue and UV component. They provide a better light quality due to their diversity of spectrum but are less efficient in ’empty’ lumens that sodium lamps that provide the orange, nearly monochromatic, light seen in the photo.
Finally, I note that if blue light encourages drivers to wakefulness, I consider that a win. Also, If you work at night, optimizing the circadian rhythm for a night active schedule is a good thing for work performance, injury reduction and personal well-being.