do leds disrupt our biological clocks?

by:Lanson     2020-03-18
You touch the light every day
LEDs (LEDs)--
They light up the alarm clock, the new TV, the traffic lights and the smartphone display.
You will see more and more white people.
The lighting version of the Led can be used for energy-
Efficient home lighting, car headlights and street lights.
What you may not know is that the most common white LEDs--
A series of colors, including blue light. -
It inadvertently effectively sends signals to our brain\'s biological clock, which regulates daily activities such as sleep.
The realization of the special sensitivity of the body to blue light stimulates scientific research on whether light can disrupt our circadian rhythm, about 24-
The animal\'s hourly cycle sets the body pattern for sleep and other biological processes.
International organizations such as Dark
The Sky Association has urged careful use of white LEDs for outdoor night lighting, and some scientists have called for a ban on the use of blue LEDs outdoors
Rich light, others estimate that the effect is small and requires more rigorous scientific research before determining whether white LED lights have any impact on health.
Some scientists believe that other factors such as lack of sleep and the overall 24-
The one-hour pattern exposed to light and darkness may play a more role in disrupting the circadian rhythm.
Epidemiology Research links circadian disruption to health issues such as cancer, cardiovascular disease, and obesity, and scientists are trying to determine whether there is light at night. -and blue-rich LEDs --are a cause.
Abraham Heim of the University of Haifa in Israel believes that white LEDs are a form of \"light pollution.
\"Environmental lighting known as \'friendly\' is unfriendly,\" said Haim, a time biologist and a scientist who studies animal biological rhythms and cycles.
His research suggests that blue light can disrupt circadian rhythms.
Hormones associated with nocturnal animals, such as rats, rats and rats.
In the most common design, white LEDs produce a mixture of blue and yellow, which the eyes think is white.
Other bulb varieties, including incandescent lamps and compact fluorescent lamps, often produce much less blue.
Until the 21 st century, scientists knew only two types of light.
Sensitive cells in the eyes: rods and cones.
But in 2001, David Berson of Brown University confirmed that the eyes of mammals contained a third cell that absorbed light.
\"This is a very exciting discovery throughout the field of time biology and visual research,\" said Jay Neitz, an eye professor at the University of Washington in Seattle.
\"We have always thought that the rods and cones are the cause of the circadian rhythm, and then we found that there is a specific cell. sends signals]
The central clock of the brain is important for the daily biological rhythm.
\"A recently discovered cell called intrinsic photosensitive retinal nodes is much smaller than the number of other light cells --
Sensitive cells-
There is only one cone per million.
But they have a key light.
A sensitive protein called Black sight
When the light shines on the black sight, it can trigger the node cells to send a signal to the supersight cross nucleus, a small brain region that regulates the circadian rhythm of the body.
Mark REIA said the newly discovered festival cells \"play a central role\" in sending signals from the retina to the brain\'s circadian system, director of the Lighting Research Center at rensler Institute of Technology in Troy, New YorkY.
It turns out that, in the wavelength range of 440 to 460 nm, the black sight protein is most sensitive to light-
Between indigo and blue
Many white LED designs create a blue light centered around 450 nm.
A 2005 study by time biologists in Basel, Switzerland, showed that human volunteers exposed to 460 nm light at night, melatonin (a hormone regulated by the human circadian system than when they are exposed to a yellow environment.
Higher green light
550 nm wavelength.
Melatonin, in addition to the 24-
The hourly rhythm of waking and sleeping is an antioxidant compound that has been shown to protect biological molecules such as DNA. In the Oct.
2011 Journal of Environmental Management, Haim of Haifa University and his colleagues
White LED lights are five times lower than low LED lights, the authors calculate
Production of yellow pressure sodium lamps
Orange lights are often seen in the parking lot. Haim and his colleagues
The author calls for \"a complete ban on outdoor light emission at a wavelength below 540 nm \"---
And back to the old low
Design of pressure sodium lamp--
\"To reduce the effects of decreased melatonin secretion and disruption of circadian rhythm in humans and animals.
\"They also called for increased consumer awareness and for bulb producers to state the wavelength of light produced by the bulb.
However, Rea said it is important to find out the absolute reduction of melatonin caused by different types of lighting, rather than the relative reduction.
Five times more than a small amount may not be big, he said.
In addition, he believes that a simple spectral-based calculation may not be able to accurately determine the decrease in melatonin.
Instead, one must consider other factors, such as the number, source and duration of the exposed light, and how the light reaches the observer directly.
\"All these things are important in predicting what impact you will have,\" he said . \".
Haim was aware of these factors and his team wanted to follow up on a controlled study explaining them.
Meanwhile, Rea and his colleagues are working on the topic from two perspectives.
First of all, they developed a headset in 24-hour period.
They call it Daysimeter.
He said measuring the light that actually reaches the eye with a calibrated instrument would be the key next step in obtaining answers to the effects of light on health issues.
In addition, Rea and his colleagues have developed a physiological model of how light reaches the retina and translates into neural signals that reach the circadian system.
Previous studies have confirmed that the extent to which nerve signals stimulate the circadian system determines the reduction in melatonin.
This model explains the sensitivity of the eye to different parts of the visible object
The spectrum, and the level of light that triggers signals in various parts of the brain.
Short lightning does not trigger the signal of the circadian system, but exposure to light for a long time triggers the signal.
Rea and his colleagues applied the model to a hypothetical person for an hour under a white LED street lamp, and calculated that an hour of exposure could reduce levels of melatonin by about 3 to 8%.
\"3 to 8% has very little impact on modeling, but it can be important.
\"I don\'t think science has come yet,\" he said . \". Similar model-
According to his team\'s calculations, light from electronic devices such as computer screens and tablets can reduce melatonin by 7-20%.
From an angle, Rea provides another example that does not involve a white LED light.
When a colleague took part in a field hockey match, he installed a light measuring device for her.
Calculated from their model, this suppressed 20-25% of her melatonin production.
\"But it\'s not like pressing to zero,\" he said . \" \"Just like you get rid of all the melatonin, you go out and look out the window and the street lights and all of a sudden [you]
Don\'t eat any melatonin for the rest of the night.
This is not true.
So you have to know these numbers.
\"Rea believes that looking at the light at night alone will not answer the basic question of how the environment affects the biological clock.
\"You find that if you don\'t know what you have during the day, you can\'t really talk about the light at night.
Considering the rhythm of the entire 24 hours is essential, \"said Reia.
\"It\'s too superficial to talk about melatonin suppression of 3-8% and to come to any conclusion about what is healthy or unhealthy.
\"Haim calls for more detailed epidemiology research by tracking large populations over the long term to explore the relationship between light at night and health issues.
Rea recommends going beyond epidemiology.
He suggested the actual 24-
The exposure of the hour, then the experiment is designed to produce similar light
Dark patterns of animals.
Then, he says, you can test the hypothesis that light exists or not.
Dark patterns can have an impact on health.
There are also technical solutions.
Wendy Davis, a visual scientist at the National Institute of Standards and Technology, said LED technology has the potential to produce \"adjustable\" light, resulting in blue-
Light during the day, blue-poor at night.
But whether this is necessary remains to be seen.
\"In addition to our support for good, intelligent, and properly executed studies, there is not enough circadian disruption studies to determine the location, and when the study is completed, alex Boesenberg said: \"We will review and see if we need to change or what needs to be done. \" Regulatory Affairs Manager, National Electrical Manufacturers Association.
The decision on indoor and outdoor lighting \"must follow the idea of time biology,\" Haim said, and do not neglect the biology of humans, wildlife and other animals.
He called for more research on animal models to look for biological effects of light.
There is no clear answer at this point and Rea suggests that people maintain a fairly consistent 24-
Arrange hours as much as possible, which may be the safest way to keep the circadian system normal, without any possible adverse effects on health.
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