Light & Health - Design Strategies & Technologies

February 12, 2015

Konstantinos Papamichael, Ph.D. Professor, Department of Design Co-Director, California Lighting Technology Center University of California, Davis

RESEARCH INNOVATION PARTNERSHIP 633 Pena Drive, Davis, CA, 95618 | cltc.ucdavis.edu | PH: 530-747-3838, FAX:530-747-3812 The Main Source of & Life

2 The Sun

3 Spectral Distribution of Sunlight

4 The Electromagnetic Spectrum

5 Daylight Spectral Power Distributions

6 The Dynamic Nature of Daylight

7 Daylight Spectral Power Distributions

http://www.handprint.com/HP/WCL/color1.html 8 Daylight Correlated Color Temperature (CCT)

http://www.lrc.rpi.edu/programs/nlpip/lightinganswers/fullspectrum/comparisons.asp

9 Human Evolution - Sunrise

10 Human Evolution - Daytime

11 Human Evolution - Sunset

12 Human Evolution - Night

13 Human Evolution - Light at Night

14 Human Evolution - Light at Night

15 Visual & Circadian Pathways

1. Visual Pathway

– Light stimulates the cerebral cortex for vision & perception

2. Biological Pathway

– Light causes messages along a biological pathway (Hypothalamus, Pituitary, Pineal Gland) that are used to regulate the body’s autonomic nervous and endocrine systems

16 Anatomy

Ciliary Muscle! Sclera!

Iris! Vitreous Humor!

Fovea! Pupil! Eyelens! !

Optic Nerve! Cornea! Aqueous Humor!

Suspensory ligament! Choroid!

17 Structure

18 Rods () & Cones ()

19 & Rhodopsin Sensitivities

http://www.handprint.com/HP/WCL/color1.html http://hyperphysics.phy-astr.gsu.edu/hbase/vision/bright.html

20 ipRGC () intrinsically photosensitive Retinal Ganglion Cell

• • SpecializedPhoto pigment ganglion cell • • ManySpecialized & long tentacles • Melanopsinganglion photopigm cells ent

• • BiologicalBiological path path

• • CircadianCircadian Rhythms rhythms

• • PupillaryPupillary (+?) reflexcontrol

21 Adaptation Mechanisms

• Mechanical change: pupil diameter

– Admits varying amounts of light – Factor of about 5% • Photochemical change: changing amounts of photo pigments available

– Bleaching makes less pigment available – Factor of about 1000% • Neural change: changing synaptic interaction

– Lower overall neural sensitivity as light level increases – Factor of about 1000%

22 Photopic, Scotopic & Circadian Sensitivities

23 Circadian Rhythms

• Endogenous (self-sustained) rhythms • From the Latin – “circa” = approximately – “dies” = day • Have been observed even in single celled organisms including prokaryotes, e.g,. bacteria • Major Biological Effects – Hormone Excretion • Melatonin - sleep-wake cycle • Insulin - carbohydrate metabolism • Cortisol - blood pressure & sugar levels – Body Temperature – Cognitive performance – ...

24 Melatonin & Cortisol Circadian Rhythms Incandescent Spectral Power Distribution

26 Pros & Cons of Incandescent Lighting

• Pros – Excellent color rendering - 100 CRI – Excellent for well-being & health - low blue content – Excellent dimming - smooth, further reducing blue content – Excellent drama - sharp shadows – No flicker! – No noise! – Low cost

• Cons – Low luminous efficacy

27 Fluorescent Lighting CCT (K)

2700 3000 3100 3500

3500 4100 5000 6500

28 Fluorescent Spectral Power Distribution

29 Spectral Power Distributions

Natural Daylight Cool White Fluorescent Tri-Phosphor 3500K

Incandescent Daylight Fluorescent Metal Halide

30 UC Davis Medical Center Sign

Photopic Illuminance: 2 fc - Scotopic Illuminance: 200+ fc

31 Photopic, Scotopic & …Cirtopic? Lumens

?

200

2

32 Blue-rich Light at Night

33 American Medical Association - June 2012

Light Polluon: Adverse Health Effects of Nighme Lighng Report 4 of the Council on Science and Public Health (A-12) of the American Medical Associaon

Biological adaptaon to the sun has evolved over billions of years.

The power to arficially override the natural cycle of light and dark is a recent event and represents a man-made self-experiment on the effects of exposure to increasingly bright light during the night as human sociees acquire technology and expand industry.

Among the laer (health effects) are potenal carcinogenic effects related to melatonin suppression, especially breast cancer. Other diseases that may be exacerbated by circadian disrupon include obesity, diabetes, depression and mood disorders, and reproducve problems.

Due to the nearly ubiquitous exposure to light at inappropriate mes relave to endogenous circadian rhythms, a need exists for further muldisciplinary research on occupaonal and environmental exposure to light -at-night, the 34 Blue-rich LED & Circadian Sensitivity

35 Key Lighting Design Strategies for Health

• Reduce exposure to blue light during the night – Outdoor lighting • Luminaires • Signage – Indoor lighting - especially residential • Luminaires • Televisions • Computer displays • Increase exposure to blue light during the day – Daylight! – High CCT light sources for applications that need it • Offices • Schools • Work spaces • Assisted living housing

36 Implementation Strategies & Technologies

• Outdoor Lighting – Occupancy-based bi-level lighting • Single Source – Full output during occupancy – 50% or less during vacancy (10% - 20% is enough) • Dual Source – High level Low CCT white light during occupancy – Low level Amber or Amber-Red LED during vacancy • Indoor Lighting – Nighttime • Low CCT (less than 3,000k) • Low level Amber or Amber-Red LED for nightlight – Kitchen – Bathroom – Way finding – Daytime • Daylight! • High CCT lighting - for applications that need it

37 High CCT Lighting for Offices & Schools

• Mills, Peter R., Tomkins, Susannah C. and Schlangen, Luc JM. “The effect of high correlated colour temperature office lighting on employee wellbeing and work performance.” Journal of Circadian Rhythms, 11 January 2007, pages 2-5.

• High CCT Electric Lighting in Call Center with Shift Work

• Reduced fatigue (26.9%) • Increased alertness (28.2%) • Reduced daytime sleepiness (31%) • Increased work performance (19.4%) • Increased vitality (28.4%) • Increased mental health (13.9%)

38 Melatonin Suppression

Brainard, George C. “Action Spectrum for Melatonin Regulation in Humans: Evidence for a Novel Circadian Photoreceptor.” The Journal of Neuroscience (2001): 6405-411. Web. 29 Apr. 2013.

446 477

39 Monochromatic LED Spectra Manufacturer A

400 550

446 477

40 Monochromatic LED Spectra Manufacturer B

Effective 400 550

Most Effective 446 477

41 Bathroom Light Switch with Occupancy Sensor & Amber LED Night Light

42 Dual Source Bi-level Outdoor Luminaire

Amber LED & Induction Lighting

43 Dual Source Bi-level Outdoor Luminaire

Occupancy Mode

44 Dual Source Bi-level Outdoor Luminaire

Vacancy Mode

45 Indirect Downlight Prototypes

46 Dual Source Kitchen Lighting

Full Light Output Night Lighting - Amber LEDs

47 100% 50% 25% Spectrally Tunable Lighting for Office Spaces WARM

• Laboratory Prototype • Independent control of – Intensity – CCT NEUTRAL

• Change CCT maintaining Intensity • Change intensity maintaining CCT COOL Refrigerator Lighting

White Light Amber Light 49 HONDA ZNE House, UC Davis

50 Honda House - First Floor Amber LED Way Finding Night Lighting

51 Honda House - Second Floor Amber LED Way Finding Night Lighting

52 Bathroom & Kitchen Lighting Amber LED “Toe-Kick” Night Light

54 Amber LED “Toe-Kick” Night Light

55 Kitchen Amber LED Night Lighting

56 Kitchen High & Low Amber LED Night Light

57 Living Room - High & Low Ambient Lighting

58 Corridor Lighting

59 Stairwell & Corridor Night Lighting

60 De Young ZNE House, Fresno, CA

61 Bathroom Lighting

62 Kitchen Lighting

63 Corridor Lighting

64 Maximizing Health & Sleep in the Elderly LD+A Article by Kimberly Mercier

65 Philips “Heu” Screw-based Lamp

DigitalTrends.com 66 Wireless Base - Hardwired to Wi-Fi Router

DigitalTrends.com 67 “Relax” Setting

DigitalTrends.com 68 “Concentrate” Setting

DigitalTrends.com 69 “Reading” Setting

DigitalTrends.com 70 Philips “Hue” Screw-based Lamps

DigitalTrends.com 71 Philips Circadian Lighting for Classrooms

12000K, 65fc average 6000K, 100fc average 3500K, 50fc average 2900K, 50fc average

5000K - Focus/Concentrate 6500K - Wake Up/Morning 4000K - Group Acvity 3000K - Relax

Photo credit: Philips 72 Samjin Color-Tunable Lighting SAMJIN

100% BRIGHTNESS

50%

2700K 4000K 6500K

CCT 73 74 Thank You! [email protected]

RESEARCH INNOVATION PARTNERSHIP 633 Pena Drive, Davis, CA, 95618 | cltc.ucdavis.edu | PH: 530-747-3838, FAX:530-747-3812