Context
Darkness is a fundamental resource required by biological systems. Artificial light can provide useful functionality to enhance the lives of humans, but the cost of this artificial light is damage to the darkness resource that is foundational to the lives of humans, wildlife, and the ecosystem. Therefore, light pollution must be restricted and regulated.
History
Artificial outdoor lighting has been used for thousands of years. Candles have been used for over 5,000 years.[1] Rushlights were described at least as far back as the 1600s.[2] Gas lighting made its debut in the early 1800s.[3] Electric lighting arrived in the late 1800s. The invention of outdoor LED lights had a massive effect on the lighting industry beginning in the 2010s.
Discussion
LED outdoor lights have dramatically reshaped our nighttime world. LED lights are inexpensive, use very little energy and produce almost no heat. The small size of the light emitter allows manufacturers to design new types of lighting that did not exist previously. The LED can also be controlled via electronics to dim or change colors.
With this invention has come new problems. Most previous outdoor lighting was a soft color temperature, like a candle flame or firelight. A typical incandescent light bulb measures 2500 Kelvin. Because of the engineering of LED lights, the easiest to produce and most efficient LED contains a high level of blue wavelength light. A typical outdoor light might be 4000K or 5000K. This high color temperature increases light pollution and causes emotional anxiety for sensitive receptors. These lights are often described as “harsh” or “very bright”.
High color temperature lights can damage the eyes, disrupt sleep, and interrupt circadian rhythms. The health and environmental risks caused by these lights is well documented.
Issues
Light Pollution
Darkness is a critical resource that must be protected for the health, safety, and proper functioning of biological systems. Outdoor lights are a source of light pollution that must be regulated to minimize its impacts on the dark environment.
One aspect of outdoor light pollution is called glare. Human eyes are designed to use reflected light to view objects. A bare-diode light that emits photons, especially high energy blue wavelength photons, directly into the eye causes the photons to bounce around within the retina, causing disabling glare. The result is a loss of image acuity for the scene and damage to the photoreceptors of the eyes.
Another aspect light pollution is contrast, which is the difference between the dark night and the bright lights. The greater the difference in contrast, the more effort your eyes go through to adapt to the changing light conditions. This effort results in muscle fatigue in the eye.
Light pollution in the form of high color temperature can be mentally torturous, especially for sensitive receptors. The high energy, blue wavelength light can cause anxiety, anger, agitation, and even thoughts of suicide. High color temperature light also increases disability glare.
Being able to view the stars is a fundamental human right. No rights were granted by any authority to allow people to block our view of the stars and since no such rights were granted, the authorities must dictate that our view of the stars be restored. The first step in restoring the stars is dimming, shielding, and removing the outdoor lights.
Excess light from outdoor lights contributes to overall light pollution that damages the darkness resource and harms biological systems.
Sensitive Receptors
The emotional component of being hit in the eyes by high energy blue wavelength light cannot be overstated. The eyes are a very sensitive instrument and a person hit in the eyes with such high intensity light will be angry and agitated and may act aggressively. Repeated encounters with these high energy lights can lead to eventual mental collapse due to the similarity to torture.
Sensitive receptors have told us that high color temperature outdoor lights are mentally disturbing. There is an emotional component of the blue wavelength light that causes sensitive receptors to become agitated, angry, or depressed. These lights disrupt the darkness resource that sensitive receptors are well tuned to.
Safety
There is a widely held assumption that bright lights will keep us safer from crime; however, this assumption is not supported by the research. A 2015 study found no convincing evidence that street lighting reduced crime.[4]
A review published by the U.S. Department of Justice of seven studies undertaken in the 1970s concluded that improved lighting was not an effective means of preventing crime.[5]
Figure 1 shows an example. The area is lit with bright white lights, and yet this did nothing to prevent the break-in. Watch the video here: https://youtu.be/8ZlvfMO9a9g
Figure 1 – Crime Under Bright Lights
Crime occurs during the day and the night. Time of day or time of night does make a difference in crime levels, but the research shows that bright lighting does not have the desired effect of making us safer. Figure 2 shows violent crime rates over the period of 24 hours. Notice how the graph shows crime rates increasing as the daylight hours go by and then begins decreasing by typical bedtime. Similar studies have shown that property crimes also happen at about the same rate in the day as in the night.[6] Therefore, adding artificial light at night is not going to reduce crime since crime rates occur equally in daylight hours and nighttime hours.
Figure 2 – Violent Crime by Time of Day[7]
Human Health
High energy, blue wavelength light has been shown to both damage the photoreceptors of the human eye and on circadian rhythms[8].
A recent study found that there is a strong correlation between artificial light at night (ALAN) and emotional disorders, including a correlation between ALAN and an increased risk of developing bipolar disorder.[9] Another study found a correlation between ALAN and increased breast cancer risk.[10]
Ecosystem Health
Nearly all biological systems use the cycle and daylight and darkness to function. One of the main triggers of cellular function is blue wavelength light, which we receive from the sun. The blue wavelengths trigger processes at the cellular level that control eating habits, sleeping and many other functions. Outdoor lights at night introduce light that damages the darkness resource.
Fireflies need a dark night to communicate and attract mates. The fireflies rely on bioluminescence to find their partners and ALAN interferes with this process. [11] Outdoor lights and light pollution are significant factors in the decline of firefly populations.
Many birds navigate at night by the light of the moon and stars. When we add artificial light from outdoor lights, we affect the ability of birds to navigate.
Glare
Glare is caused by a significant ratio of luminance between the task (that which is being looked at) and the glare source[12]. Figure 3 shows an industrial building with high color temperature lights. The high blue content causes disabling glare and makes it uncomfortable or even painful to look at the building.
Figure 3 – Glare from Industrial Building Lights
These lights are not directed downward, so the light rays trespass beyond property lines and cause light pollution. The glare from the high color temperature causes eye damage and reduces visibility.
Color Temperature
A high color temperature LED light has a profound impact on sensitive receptors. Many Highly Sensitive Persons are unable to “tune out” the lights. Instead, the light is a source of distraction and cause of mental anguish. Highly Sensitive Persons tell us that these lights force them to stay indoors due to the emotional disturbance that they cause.
Figure 4 shows high color temperature parking lot lights. These lights will appear as harsh or very bright in person. As you can see in the photo, colors are washed out and it will severely impact any birds, insects or other wildlife trying to sleep.
Figure 4 – High Color Temperature Parking Lot Lights[13]
Contrast
In the dark, nighttime environment, our eyes switch to using rod cells to be able to see in the darkness. This is called scotopic vision and allows to see detail with very low levels of light, but with the loss of color. As brightness increases, we switch to photopic vision that uses our cone cells to give us color and to be able to cope with the larger amounts of light.
When our eyes must switch between darkness and brightness, our pupil needs to dilate or contract to increase or decrease the amount of light entering the eye. This effort requires energy which can tire our eyes. Therefore, it is important to limit the contrast between the dark night and the bright lights. We can accomplish this goal by requiring shielding and diffusion, by limiting the luminous flux and luminous intensity of the light and by limiting color temperature.
Fuel Stations
Figure 5 shows high levels of glare and light trespass from a gas station. The difference in contrast between the dark night and the bright gas station is a distraction for drivers and leads to eye fatigue. The lighting at this gas station is also contributing to overall light pollution.
Figure 5 – Glare and Light Pollution from Gas Station[14]
Figure 6 shows a gas station with lighting measured at 8 foot-candles. Lighting industry representatives push high color temperature LED lights because they sparkle and supposedly convey a message that the location is safe and inviting. However, a study at the Lighting Research Center at Rensselaer Polytechnic Institute found that more drivers stopped at gas stations that had less glare.14
Figure 6 – Soft Light at Gas Station14
Residential
Figure 7 shows high color temperature, high glare light that trespasses beyond property lines and produces excess light pollution while providing no useful functionality since no one is using the light.
Figure 7 – Light Trespass from Residence[15]
Figure 8 is an example of the installation of a light that was meant to provide illumination to help the resident take out the trash at night, but instead causes blinding glare and reduced vision. Figure 9 shows the same fence, but with a soft, low lumen light with almost no glare and little light pollution.
Figure 8 – Fence Light15
Figure 9 -Soft, low intensity fence light15
Lights from Windows
A non-trivial source of light pollution is light emitted from inside a building and escaping through the windows. This escaped light is a significant source of the hundreds of millions of bird deaths each year. Figure 10 shows light pollution emanating from office building windows and the windows of a residence. While the lights are soft and warm, they are nevertheless a source of light pollution.
The light escaping from the windows is pollution, not serving a useful purpose and does not help the people inside see. In fact, the safety of those inside the house is compromised because outsiders can see in.
Figure 10 – Light Pollution from Windows
Pathway Lights
Figure 11 and Figure 12 show decorative pathway lights adding light pollution into the environment.
Figure 11 – Pathway lights pointing up.15
Figure 12 – Pathway lights causing light pollution15
Figure 13 shows a large quantity of string lights decorating a fence. While each emitter is soft and of low intensity, the sheer quantity of lights leads to light pollution.
Energy Use
Figure 14 shows an example of lights attached to a commercial building. There is nobody using these lights, and yet energy is being used to illuminate the empty parking spaces.
Figure 14 – Wasted energy for building lights
Proposed Regulations
Darkness is a fundamental resource that is needed for the proper functioning of biological systems. Anthropogenic artificial light damages the darkness resource and therefore must be limited and regulated. We propose that outdoor light be regulated as light pollution.
We propose the following regulations:
- Set a maximum color temperature of 2700K and a minimum Spectral G-Index of 1.56 for all outdoor lights.
- Require that all outdoor lights have shielding and diffusion with a BUG rating of (B0, U0, G0).
- The luminous intensity maximum at the property line should be set at 90 lux for commercial areas, 40 lux for residential, and 20 lux for rural.
- The luminance value at the eye from any light emitter or set of emitters shall not exceed 50 nits.
- Office building and resident windows shall be covered with a shade or curtain to prevent light pollution from escaping from indoors to outdoors.
- Outdoor lights shall not blink, flash, or strobe.
- In commercial areas, all lights must be turned off at the close of business. This includes signs, indoor lights, and parking lot lights. A security light may be used so long as it is triggered by motion sensor.
- In residential areas, all outdoor lights must be turned off by 11pm. This includes pathway lights and string lights. A security light may be used so long as it is triggered by motion sensor.
[1] https://candles.org/history/
[2] https://en.wikipedia.org/wiki/Rushlight
[3] https://lucyworsley.com/a-quick-history-of-domestic-lighting/
[4] https://www.ncbi.nlm.nih.gov/books/NBK316511/
[5] https://cops.usdoj.gov/RIC/Publications/cops-p156-pub.pdf
[6] https://www.thesleepjudge.com/crimes-that-happen-while-you-sleep/
[7] https://www.ojjdp.gov/ojstatbb/offenders/qa03401.asp
[8] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4734149/
[9] https://jamanetwork.com/journals/jamapsychiatry/fullarticle/2767698
[10] https://ehp.niehs.nih.gov/doi/10.1289/ehp935
[11] https://www.sciencedaily.com/releases/2020/02/200204094744.htm
[12] https://en.wikipedia.org/wiki/Glare_(vision)
[13] https://www.bizjournals.com/southflorida/news/2020/03/27/how-a-florida-shopping-center-saved-money-and.html
[14] http://www.flagstaffdarkskies.org/dark-sky-solutions/dark-sky-solutions-2/service-station-lighting/
[15] Soft Lights
[16] https://blog.1000bulbs.com/home/summer-2018-patio-string-lights