Have you been invited to speak to your city? If so, congratulations for this opportunity! I hope the outline below can assist you. Other than a few minor tweaks, this is the outline I made and discussed with my city in 2017. Feel free to use and edit this outline (for the lighting choices, find amber LED suppliers who can work with your city). These points resonated very well with them, but all cities are different. I was lucky to have a gracious audience and a city that had an interest. In early 2018, brand new streetlights went up and down a couple of our highways. Instead of installing new fixtures with white LEDs, my city chose fully-shielded, amber lighting. Did my meeting make the difference? I don't know for sure, but I'm definitely glad I went, and I'm thankful for the light pollution scientists and lighting engineers around the world, without whom, my meeting would not have been possible! I continue to follow up every 6-12 months for updates on any lighting changes.
Update: Sadly, as of March of 2019, new people are in charge, and my city has now chosen to install harmful, white LEDs. It is of course my hope that those in charge will listen to reason and chose lighting that is responsible for all.
Money & Safety tend to get cities' attention the most, and if you're in an area where darker skies could be good for tourism, be sure to emphasize that as well! If you're looking for more studies on light pollution, see Artificial Light at Night (ALAN) Research Literature Database.
A GREAT OPPORTUNITY
As we now have the fortunate option to change our streetlights, we have the chance for lighting that will be cost-effective, pleasant, safe for people, wildlife and to partially reclaim our night sky again.
We can choose cutting edge lighting that has yet to be used by any other major US city. We can lead the way and help put a stop to the dangers that white LEDs are having across the country.
With smart and thoughtful lighting choices, we ALL win.
Amber LEDs are more efficient than HPS lights and can save the city a lot of money. See topic VI.
II. SAFETY & ROAD HAZARDS
Lights must not create disability glare, causing an unsafe situation to drivers and pedestrians and city liability for not choosing safe lights.
Disability glare reduces the ability to resolve spatial detail. 1
Blue light (from blue-rich LEDs) causes more scattering in the eye which leads to a veiling luminance over the retina and can have serious implications for nighttime drivers. 1
It takes the elderly longer to recover.
An example is the effect bright white/blue headlights have on your eyes when you drive past them.
The intense point source of LEDs can cause visual discomfort, especially among older drivers.
It’s important the lights are fully shielded. 1 Shielding the light also allows the light to go to the ground, where it’s needed, rather than wasting it pointing to other directions.
Lights that are too bright hurt our eyes causing squinting and even temporary loss of vision.
Lighting and Road Accidents
Some studies show more light does not equal less traffic accidents. 4
4000K light is seen as harsh and studies show it leads to disability glare and discomfort.
Many cities have been unhappy with 4000K like Davis, CA, New York City, Cambridge, MA. saying it’s uncomfortable and looks like “prison” or “zombie lighting.”
Expenses to cities after choosing white LEDs has been substantial.
Davis switched to 2700K, but it cost the city an additional $350,000. 2
Monterey, CA has endured 80,000 in legal fees due to being sued by citizens because of white LEDs. 3
3000K is better, but it still has 21% blue emissions. 1
The AMA strongly recommends using either amber light or filters that block blue wavelengths, and the AMA recommends the following: 1
Using the lowest emission of blue light possible.
Using fully shielded fixtures to minimize glare and light pollution.
Choosing lights that can be dimmed during off-peak hours.
II. SAFETY & CRIME
It’s important to realize that more light has not been proven to equal less crime 4, and streetlights don’t prevent it. 5 However, not all studies agree or show that less light equals less crime, but these studies seem to be in the minority. 7
In England, 106 out of 141 councils either dimmed their streetlights or turned them off completely after midnight in order to save money, and over a 14 year period, researchers were unable to find an increase in either road accidents or crime that could be related to the change in lighting. However, light does make people “feel” safer. 6
Perhaps we could save money by also dimming or turning lights off after midnight where appropriate.
III. SAFETY & HEALTH
Studies show blue light exposure at night is unhealthy.
Disrupts circadian rhythm (5 Xs as much as HPS lights). 1, 9
There is evidence showing it can lead to cancer, heart disease, obesity, diabetes, depression, insomnia and heart problems. 1, 9, 10, 11
Residential areas especially need protection from blue light shining into windows and from exposing people to blue light who are winding down, taking an evening scroll outside, etc.
IV. SAFETY & WILDLIFE
60% of animals are nocturnal and potentially affected by blue light at night. 1, 12
Blue light at night can have devastating effects on precious birds, insects, bats, baby sea turtles, and fish. 1, 12
Blue light at night causes needless suffering to wildlife and disrupts the ecosystem. 1, 12
V. LIGHT POLLUTION
Moisture in the air picks up blue light.
Blue light dramatically creates more sky glow, 1 which forces people to travel even further from the city to see the stars.
The night sky fosters dreams, imagination, the desire to learn, a connection to our universe and it is something all people should be able to enjoy.
By 2025, there will be very few places left in the United States away from light pollution 13 where the night sky can be appreciated unless changes are made—but cities like Dallas can help stop this with smart and thoughtful lighting choices.
Dimming the lights during off-peak hours saves energy, wildlife and helps with light pollution.
VI. WHAT ARE SOME LOW BLUE LIGHT CHOICES?
PC Amber LED (My top pick!) by Kim Lighting (Hubbell) Ask to speak with Matt Root.
Very low blue emissions.
Safer for people, wildlife and would lessen skyglow.
A pleasant color while still having a high CRI of 65-70—much higher than HPS.
Uses aimed optics so glare and “light trespass” is minimized. The light goes “only” where it is supposed to go.
May be ideal for residential areas.
Prices and energy efficiency now at parity with white LEDs.
Kim can make custom lighting—call Matt for full details of what is available in the amber, low blue light spectrum.
More amber LED sources here: savingourstars.org/amberleds
Filtered LED by C&W Energy Solutions.
Less than 1-2 % blue light.
Safer for people, wildlife and would lessen skyglow.
A pleasant, low glare yellow. Used in parts of Hawaii on the Big Island.
Though there is a yellow tint, colors can still be distinguished.
Our current streetlight fixtures can be retrofitted with these, eliminating disposal costs of our old lights (see photos in folder).
Retrofits have a safety unit.
50-80% reduction in energy costs.
120 lumens per watt.
Light CCT can be customized.
Prices are competitive.
Half of savings will be for maintenance costs.
These lights do not have a power supply, meaning, those parts will not need to be replaced in ~7 years saving the city the labor costs of re-installing them (about $200 per light?).
The lights should last, maintenance free for about 10-15 years.
VII. BEST CURRENT WHITE LED OPTION (If amber is not an option)
Leotek 2700K. Linden. 408-380-1788
I believe this would be a step backwards from what we currently have, as it has too much blue light and could add 2-3 times the amount of current light pollution, 8 but if the top two options do not work out, I believe this is the current best solution of the white LED choices.
Leotek is being used in Lake Worth, FL. Phoenix and Davis, CA have also chosen 2700K.
Though there is still quite a bit of blue emission, white LEDs can be dimmed quite a bit without being realized, and this is vital if a white LED is going to be used. John Barentine is using 3000K LEDs in Tucson, AZ at only 10-50% brightness/lumen capacity, and he is currently measuring less sky glow than what the old HPS lights had, which means less glare and harm to people and wildlife.
Most lights are +/- 300K of whatever they are listed as.
American Medical Association. Louis J. Kraus, MD, Chair. CSAPH Report 2-A-16. Human and Environmental Effects of Light Emitting Diode (LED) Community Lighting. 2016.
James R. Benya, PE. City’s LED Retrofit Shows Needs for Careful Lighting Choices. 2015.
Nick Rahaim. City of Monterey loses lawsuit over streetlights. Monterey County Weekly. 2017.
Alissa Walker. Streetlights Don’t Actually Prevent Crime. 2015.
The Independent. Turning off street lights does not cause increase in traffic accidents or crime, says study. 2015.
Mike Riggs. Street Lights and Crime: A Seemingly Endless Debate. 2014.
Flagstaff Dark Skies Coalition. Lamp Spectrum and Light Pollution. 2016.
British Journal of Cancer. Louise E Johns, Michael E Jones, Minouk J Schoemaker, Emily McFadden, Alan Ashworth & Anthony J Swerdlow. 118, pages 600–606. Domestic light at night and breast cancer risk: a prospective analysis of 105 000 UK women in the Generations Study. January 23, 2018.
Advances in Integrative Medicine. Randy J.Nelson, A. Courtney DeVries. Volume 4, Issue 3, Pages 115-120.
Medical hypothesis: Light at night is a factor worth considering in critical care units. December 2017
American Journal of Epidemiology. Kenji Obayashi, Keigo Saeki, Norio Kurumatani. Volume 187, Issue 3, 1 March 2018, Pages 427–434. Bedroom Light Exposure at Night and the Incidence of Depressive Symptoms: A Longitudinal Study of the HEIJO-KYO Cohort. March 2018.
Global Change Biology. Erin L. Koen, Corneile Minnaar, Carrie L. Roever, Justin G. Boyles. Emerging threat of the 21st century lightscape to global biodiversity. 25 March 2018.
National Park Service. Lightscape / Night Sky. February 2015.