LED’S: Not the answer to eye and environmentally friendly lighting
By Francis Parnell
While LED’s (Light Emitting Diodes) are quickly becoming the way to light the 21st century, research has shown that there’s a “dark side” to this new type of nighttime lighting.
Francis Parnell, the Backyard Stargazer of Darlington
Due to their current design, the popular 3000K to 6500K (Kelvin) LED’s that are being installed all across the country are causing many problems because this White Light (Blue-Rich White Light) is loaded with short wave-length blue and green light which have much higher environmental impacts. These short wave-lengths are detrimental to us, nocturnal mammals, reptiles, insects, amphibians, and the nighttime environment as a whole.
Our eyes perceive this blue component as being 3 to 5 times more intense and glary than the yellow-orange High Pressure Sodium (HPS) lights than we’re used to seeing at night. It scatters more in our eyes creating a “veiling” effect making it more difficult to see. For older drivers and those with impaired vision this can be a dangerous situation. Our visual system responds well to white light in the daytime – but not at night!
Our dark adapted (nighttime) eyes are much more sensitive to the shorter (bluer) wave-lengths than light adapted (daytime) eyes. Light sources producing more blue light will appear many times brighter (more glary) to our dark adapted eyes.
Even without changing the amount of light or shielding, switching a lighting installation from High Pressure Sodium to 4100K LED will increase sky glow as if the amount of HPS lighting had been increased by 170%, or nearly tripled. And research in Australia has shown that compared to other types of lights at night such as High Pressure Sodium and Low Pressure Sodium (LPS), LED’s attract 48% more insects – LED’s are an insect death trap – they suck the insects completely out of the environment. Even our old familiar incandescent bulbs weren’t this bad! For both humans and all nocturnal creatures, the one thing we shouldn’t do when it comes to light at night is to turn it into a “White-Light” night.
The best type of lamp to use for outdoor lighting at night is High Pressure Sodium (HPS) as it causes the least environmental impact. Compared to “blue-rich” LED’s, the glare in our eyes will have lots less impact too!
Correlated Color Temperature (CCT) is a number used by lighting companies to identify the “perceived color” given off by light sources measured in degrees Kelvin (K). But it is not an accurate way to determine the actual amount of blue and green from any light bulb (lamp) or LED. CCT is a very crude way to describe how “warm” or “cool” a light appears to the human visual system. Lower temperature CCT appears “warmer” and more eye friendly while higher temperature CCT looks “colder” and harsher to our eyes.
There’s a saying that “The world runs on perception and not on reality.” Across the country, city/county leaders are rushing to install LED’s without any knowledge of outdoor lighting – LED lighting especially – and the complaints from citizens have been very vocal. With all of the extensive research done in Europe and the U.S. in the last few years, find out about this new type of lighting before making decisions that will last for 30 years or more. Go with the research and not the “sales pitch” from your local utility; go with the facts and what your eyes tell you – not your perception. Because turning our cities and towns into Perpetual Daylight would be the worst decision leaders could ever make.
The complaints from citizens in cities that have installed LED’s have been heard. Some lighting companies are beginning to address the “blue-rich” problem. But the best thing for leaders to do is wait until the lighting companies get the problem corrected.
In December of 2014, General Electric published a White Paper on the problems with “Blue-rich” LED lighting. And at the American Medical Association (AMA) meeting in June of 2016, the delegates voted unanimously to support “getting the blue” out of LED’s.
Best for light pollution (LP) reduction:
1. Narrow-Band Amber LED (NBALED) narrow-spectrum yellow-orange; almost equal to LPS in LP reduction.
2.Phospher-Converted Amber; similar to High Pressure Sodium.
3. LED 2400K; A warm white LED, that has not seen wide use.
4. FLED Filtered LED; removes wavelength of light less that 500nm (nanometers).
For the latest research on the problems with LED’s go to Flagstaff Dark Skies Coalition at flagstaffdarkskies.org and the Illinois Coalition for Responsible Outdoor Lighting (ICROL) at illinoislighting.org.
Francis Parnell of Darlington has been a frequent contributor to the News & Press over the year and has been an amateur astronomer for over 46 years. He was on the staff and helped out at the Francis Marion University Observatory from 1982 until 2006 by showing visitors “what’s out there.” With the help of a friend, Mr. Ernest Lowry, he built his own telescope in 1986. As an opponent of light pollution, for the last 31 years he has been advocating for the advantages of using fully-shielded lighting at night.
