Talking about the deficiencies brought by LED street lights
The color temperature of an incandescent lamp is 2400K, which means that it emits less blue light and more red and yellow light. Before the advent of electric lights, we burned wood or lighted candles at night. The color temperature of this artificial light was around 1800K, almost completely yellow/red light, and almost no blue light. This is completely different from the situation we are facing now.
According to the AMA report, the new "white" LED street lights, which are currently popular across the country and quickly spread in many cities, have two problems:
The first is dazzling and uncomfortable. Because this kind of LED light has a narrow spectrum and a lot of blue light, it will be very dazzling and will make the pupils constrict. Blue light is easier to scatter in human eyes than long-wavelength yellow light and red light, and it will damage the eyes after reaching a certain level. This will cause safety problems for safe driving and walking at night. You can easily verify this. Try to look directly at the indicator lights of your new washing machine or other electrical appliances. You will find it difficult because the light makes you uncomfortable. Street lights can have the same effect, especially since it has a lot of blue light and there is no proper shielding.
The second problem is the effect of this kind of light on the body clock.
Studies have shown that: the full moon affects sleep.
Color temperature can accurately describe the spectral content of light, which means: how many different wavelengths of light are contained in the emitted light. This is designed to measure the light emitted by the tungsten filament in the incandescent bulb.
However, the color temperature is not very accurate for measuring the color spectrum of fluorescent lamps and LED lamps. Another set of measurement systems called correlated color temperature (CCT) is used to measure this type of light source. It adjusts the spectral content of the light source to the sensitivity of human vision to color. Using this measurement method, two different types of light sources with a color temperature of 3000K will have a huge difference in blue light content.
Therefore, AMA believes that CCT lower than 3000K can not guarantee the reduction of blue light. When selecting LED lamps, the exact sub-illuminance value of the LED lamp should be considered at the same time-the corresponding amount of each color light produced by the lamp.
Causes of health problems caused by lighting
The AMA's official statement came in a particularly timely manner. The world's artificial lighting night brightness map updated last week showed that street lights are the main component of light pollution. According to the AMA statement, one of the problems caused by night lighting is its impact on human health.
Light has an impact on our biological clock, and it will bring serious health consequences.
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At night, white LED lights are expected to be five times stronger than high-pressure sodium lamps of the same brightness in suppressing melatonin, which has been the backbone of street lights in the past few decades. Melatonin suppression is a sign of circadian clock disturbances, leading to sleep disorders.
Bright nights can also affect wildlife, such as landmarks that interfere with migrating birds, and some aquatic animals that nest on the shore.
