"The street lights of LEDs have problems in terms of health and safety," the American Medical Association announced, and on what impact will it have?

ByFrankieleon

There are two types of incandescent bulbs, incandescent lamp and white LED, but when comparing the two, the LED has the feature that its power consumption is overwhelmingly low, and additionally it is considerably brighter than the incandescent lamp. Although it is brighter, it is a white LED adopted in many places because it saves energy,American Medical Association(AMA) warns that "White LEDs used in street lights have health and safety issues."

American Medical Association warns of health and safety problems from 'white' LED streetlights
https://theconversation.com/american-medical-association-warns-of-health-and-safety-problems-from-white-led-streetlights-61191


In the official Annual Report, AMA revealed to dim the LEDs used for road lighting and darken it. This decision revealed in the annual report seems unanimously decided in the annual general meeting of AMA held in Chicago on 14 June 2016. In the United States in recent years, the use of LEDs in street lights is accelerating, LEDs are also used for street lamps in Seattle and New York. In the decision decided in that, AMA opens up guidelines on LED usage, "to minimize the adverse effects on human health and the environment potentially owned by the LED light used for street lighting" It is.

Many local governments in the United States have replaced existing street lights with LEDs to save energy and improve the maintainability of streetlights. However, AMA pointed out that there are two major problems with LED street lights.

ByOzzy Delaney

In the annual report, AMA says that outdoor lighting at night, especially street lights should be kept to about 3000 K at high color temperatures.Color temperatureIt is a unit that expresses the color of the light emitted by the light source in a quantitative numerical value, and the "bulb color" of indoor lighting is set to about 3000 K. The color temperature becomes closer to blue as the value increases, and the color temperature of the white LED is 4000 to 5000 K. This white LED seems to be pure white light, but the blue light with the strongest energy among visible light,Blue lightIt contains a lot.

On the other hand, the color temperature of incandescent bulbs used in many families before LEDs are popular is about 2400 K. This means that there are fewer blue lights than LED lights, and they contain more yellow and red light longer in wavelength than blue lights. Before the light was invented, human beings burned the trees to create lights, but the color temperature of the light which can be burned with wood and the like is about 1800 K, more yellow and red light than incandescent light bulbs It does not include blue lights. However, as LEDs have become widespread, white LEDs are used as lighting everywhere from indoors to outdoors.

The problem with that white LED is that one is "to emit a dazzling glitter light". The LED light is condensed blue light, which will emit a very dazzling light. However, since the blue light emitted from the white LED reflects more in the human eye than the yellow / red light with a long wavelength and damages the retina, the pupil of the eye excessively shrinksMiosisIt also causes it. If you stare at the white LED for a while, your eyes will be painful and you will have to close your eyes. "This shows well that the light emitted by the LED is too strong," said the international news siteThe Conversation.

ByMike Mozart

The second problem of white LEDs pointed out by AMA is "Circadian rhythmInfluence on the ".

Although it is predictable what color light is included from the color temperature, it seems that it is impossible to measure the color of the light emitted from the LED at the color temperature. There used to beCorrelated color temperature(CCT) is an indicator called. In CCT, it seems that you can see which of the same 3000 K light also contains more blue lights. Therefore, AMA is insufficient by merely selecting the LED so that the color temperature becomes 3000 K or less.

The annual report of AMA was released to show how artificial light at night is emitted all over the world "The World Atlas of the Artificial Night Sky Brightness"Is very close to the timing when it was released, and artificial light in this map will contain many LED street lights, The Conversation.


Also, AMA describes the influence on the human body due to nighttime LED street light, and the white LED is also famous as lighting in the tunnelSodium lampRather than nightMelatoninIt has also been found that it reduces the volume five times. Suppression of melatonin leads to the collapse of the circadian rhythm and there is a risk of developing into sleep disturbance from here. It is also suggested that excessive light from the LED street light may adversely affect wild animals.

In light of the energy efficiency and the influence on the human body, AMA recommends the use of white LEDs while controlling the lighting so that the blue light is minimized.