LED Lighting and the AMA. Dr. Ronald B. Gibbons Director Center for Infrastructure-Based Safety Systems

Transcription

1 LED Lighting and the AMA Dr. Ronald B. Gibbons Director Center for Infrastructure-Based Safety Systems

2 Health Impacts and Subjective Color Circadian rhythm, hormone secretion: The hormones responsible for the circadian rhythm in humans are melatonin, which is released in response to increasing levels of darkness and which promotes sleep, and cortisol, which is the biological opposite of melatonin and an indicator of the level of human activeness.

3 Phase Shift Curve

4 Health Impacts and Subjective Color Marianna Figueiro, et al, 2006 research reported in the Journal of Carcinogenesis

5

6 American Medical Association (AMA) 2016 report titled Human and Environmental Effects of Light Emitting Diode (LED) Community Lighting which has been relayed to the public via various news providers. The AMA key recommendation is both minimizing and controlling blue-rich environmental lighting by using the lowest emission of blue light possible to reduce glare as well as the use of 3000K or lower lighting for outdoor installations such as roadways....

7 CHICAGO - Strong arguments exist for overhauling the lighting systems on U.S. roadways with light emitting diodes (LED), but conversions to improper LED technology can have adverse consequences. In response, physicians at the Annual Meeting of the American Medical Association (AMA) today adopted guidance for communities on selecting among LED lighting options to minimize potential harmful human and environmental effects. High-intensity LED lighting designs emit a large amount of blue light that appears white to the naked eye and create worse nighttime glare than conventional lighting. Discomfort and disability from intense, blue-rich LED lighting can decrease visual acuity and safety, resulting in concerns and creating a road hazard.

8 In addition to its impact on drivers, blue-rich LED streetlights operate at a wavelength that most adversely suppresses melatonin during night. It is estimated that white LED lamps have five times greater impact on circadian sleep rhythms than conventional street lamps. Recent large surveys found that brighter residential nighttime lighting is associated with reduced sleep times, dissatisfaction with sleep quality, excessive sleepiness, impaired daytime functioning and obesity.

9 Recognizing the detrimental effects of poorlydesigned, high-intensity LED lighting.. The AMA recommends an intensity threshold for optimal LED lighting that minimizes blue-rich light. The AMA also recommends all LED lighting should be properly shielded to minimize glare and detrimental human health and environmental effects, and consideration should be given to utilize the ability of LED lighting to be dimmed for off-peak time periods.

10 AMA Report AMA has stated Use 3000k Reduces Sky Glow Reduces impact in Humans Reduces impact on Migratory Animals Reduces impact on Sea Turtles Etc. Is it an unbiased recommendation?

11 Here is what we know Light Impacts the human Melanopsin Response Peaks around 480 nm Impacts circadian rhythms, alertness Sleeping etc. Same in all mammals Interesting Circadian Response Light can keep you awake and alert Is that good or bad for a driver?

12 Response to Spectral Content Lighting Application for Non-Visual Effects of Light Andreas Wojtysiak, Alfred Wacker and Dieter Lang, Osram AG

13 IES Response Given the state of current knowledge, it is not possible to weigh the probabilities of health care concerns regarding light-at-night and its effect on sleep disruption from outdoor and roadway lighting against the needs of nighttime driver and pedestrian safety, but such deliberations should precede any policy statement that affects both concerns. Correlated Color Temperature (CCT) is inadequate for the purpose of evaluating possible health outcomes; and that the recommendations target only one component of light exposure (spectral composition) of what are well known and established multi-variable inputs to light dosing that affect sleep disruption, including the quantity of light at the retina of the eye and the duration of exposure to that light. A more widely accepted input to the circadian system associated with higher risk for sleep disruption and associated health concerns is increased melanopic content, which is significantly different than CCT. The upper CCT limit of 3000 K contained in AMA Policy H lacks scientific foundation and does not assure the public of any certainty of health benefit or risk avoidance.

14 Comparison of SPDs

15 Limitations in the Melanopic Research Performed at extremely high lighting levels as compared to roadways So what is the impact at street lighting levels? The ratio would be the same But does the magnitude make a difference?

16 Consider Light as a Drug Like every drug there are benefits and side effects. The question is: How do we determine an appropriate dose and minimize the negatives? Also we need to establish a system to determine the dose as the needs of the infrastructure changes

17 (Trends in Neurosciences, January 2014, Vol. 37, No. 1)

18 Impacts (Dosage and Duration) PNNL data

19 Looking for Just right in Lighting So what is Just Right? We judge this by a variety of Dimensions Roadway User Safety Energy Consumption Public Perception and Acceptance Environmental Impact Impact on Surrounding Areas Impact on user health Our current approach is Adaptive Lighting

20 Other impacts Vision Impacts Color Contrast Sky Glow Flora and Fauna

21 Color Temperature and Asymmetry

22 Light Source Color and Detection source/reports/seattle-led-adaptive-

23 Luminance Contrast

24 Color Contrast

25 Mesopic Results Eccentricity and Light Type 2 and 5 degree locations differ significantly from 6 and K LED had further distances at 6 and 14 degree due to more efficient spectral distribution in mesopic range (mesopic effects exist only in periphery) At 14 degrees, detection distance increases with color temperature

26

27 Visual Detection There seems to be an improvement under white sources No crash analysis at this point It is important to note that this benefit can be limited to certain applications Mesopic factors may apply but may be applicable only in the periphery The influence of the periphery can change based on the roadway type Drivers change their eye glance behavior based on the roadway type. Application factors and where to apply are still a topic of debate Scotopic Lumens do not apply

28 Sky Glow Sky Glow Blue Light Scatters more than amber light Rayleigh Scattering Molecular Scattering Molecule are about the same size as the wavelength for blue light Blue Light Scatters more Low angle blue content light is particularly bad Mie Scattering Aerosol Scattering Particles are much bigger than wavelength Not Spectrally Selective

29 Sky Glow

30 Relative Sky Glow LPS HPS MH From CORM 2008, Luginbuhl, Keith & Knox

31 Light Trespass

32 Impact on Soybean Growth

33 Yield and Moisture

34 Things we need to do Lighting Link to Safety is fairly well established Establish the Health Impacts at appropriate Dosage Both pros and Cons Alertness Melatonin at appropriate levels More info on the impact on Flora and Fauna Plants Bugs Animals Consider the Future

35 Questions?