LED (light emitting diode) streetlights have become more popular across the U.S., you may have noticed when out at night that the streetlights seem much brighter. There are various pros and cons to using LED streetlamps, we’ll discuss this and the steps that can be taken to mitigate any disadvantages.
Benefits of LED Streetlights
Disadvantages of LED Streetlights
Why do LED lights have a negative effect?
American Medical Association, or AMA released an official statement, unanimously approved by the group’s members, with guidelines on how to mitigate the potential for harm to both human health and the environment.
The main problem with them is their color temperature (CT), a numerical rating of the color hue of a light source. Higher values on the color temperature chart indicate more blue content and “cooler” lights while lower values indicate a “warmer” light with more red content. The AMA advises that outdoor night lighting should not have a CT over 3,000 Kelvin temperature; a white LED light, popular in cities like Seattle and New York, can have a CT of 4,000-5,000K. For reference, a typical incandescent bulb is about 2,700K and a candle or small fire is around 1,800K. These LEDs do not just affect circadian rhythms but may also harm the human retina if viewed for a long enough period of time. Driving at night could soon become much more difficult due to this effect.
Another issue is that while CT is a useful metric, it has its limitations, namely, it does not factor in human color perception. Correlated color temperature (CCT) is another method that accounts for how human vision is sensitive to colors. Going by this method, two LEDs with a CT of 3,000K may look vastly different from each other. One light may have more blue content than the other which would cause a shift in their hue. While the AMA’s statement is a start, this example shows that CT or CCT measurements alone are inadequate and additional metrics are needed.
How are different areas using LED lights?
Different areas of the country have had different response to the recent warnings from the AMA:
How can an organization or city be sure that their LEDs are not damaging? Konica Minolta Sensing Americas has a wide array of light measuring tools that can help. Both the CL-200A and the CL-70F can measure color temperature along with other metrics like duv or spectral power distribution (SPD) that help determine your streetlights are emitting blue content within a safe range.
For more information waterproof light fixture, please get in touch with us!