03.Jan.07

HONORS SEMINAR --  “ENVIRONMENTAL AND SOCIAL CONSEQUENCES OF ARTIFICIAL LIGHTING” 

UNIVERSITY OF DENVER WINTER 2007

Wednesdays, Noon-2pm, Honors Seminar Room, Mary Reed Hall

MODERATOR: Dr.Robert Stencel, William Herschel Womble Professor of Astronomy and Director of Chamberlin and Mt.Evans Observatories, Dept. Physics & Astronomy, Rm. 409 Space Sciences Lab (2112 E. Wesley), 303-871-2135, javascript:main.compose('new','t=rstencel@du.edu')

TEXTBOOKS – Light Pollution, Responses and Remedies by Mizon [Springer/'03] and Eco.Conseq.Night Light, by Rich & Longcore, [Island Press/'05].  

Grading policies: see http://www.du.edu/~rstencel/Courses/grading.htm 

Reference material, IDA Outdoor Lighting Handbook: http://darksky.org/handbook/lc-hb-v1-14.html ( 77 pages when printed) 
Additional reading materials: http://darksky.org/resources/library.html & http://www.coloradolighting.com/codes.htm &  http://www.greenprintdenver.org/docs/greenprint_report.pdf &  AUDIO: http://hoe.kgnu.net/hoeradioshow.php?show_id=283 

APPROXIMATE SCHEDULE* W2007 - subject to revision as conditions evolve  

RATIONALE: 

IT IS SAID THAT ENVIRONMENTS ARE INVISIBLE, THEIR GROUND RULES AND PERVASIVE STRUCTURES ELUDE EASY PERCEPTION. THIS IS TRUE OF ARTIFICIAL LIGHTING.  

EVERYONE IN MODERN CITIES TAKES IT FOR GRANTED, AS A FACT OF NATURE AND AS AN INVISIBLE BACKGROUND TO OUR NIGHTLY LIVES OUTDOORS. HOWEVER, MOST OF THIS LIGHT IS GENERATED BY THE BURNING OF COAL AT POWERPLANTS, RESULTING IN RELEASE OF GREENHOUSE GASES CO2 AND H2O. 

BADLY AIMED LIGHT CREATES GLARE, TRESPASS AND LIGHT POLLUTION. BADLY AIMED LIGHT ALSO CONFUSES BIRDS, SEA TURTLES AND PILOTS, SOMETIMES TO THEIR DEMISE [SCIENCE NEWS COVER STORY, 4/20/02]. 

CITY, STATE AND NATIONAL LEGISLATION NOW EXISTS IN FACT OR DRAFT FORM TO ADDRESS THE MULTIPLE PROBLEMS RELATED TO POOR LIGHTING - BUT IS IT ENOUGH?.

LEARNING OBJECTIVES: AWARENESS OF USES OF ARTIFICIAL LIGHTS (ENVIRONMENTAL), DEVELOPING PROFICIENCY FOR QUANTIATIVE MEASUREMENT AND ASSESSMENT OF LIGHT QUALITY (TECHNICAL), MEDIATION BETWEEN CIVIL AND COMMERCIAL USES OF LIGHTING (LEGAL).   

PROPOSITION: OUR QUALITY OF LIFE IS PROPORTIONAL TO THE QUALITY OF LIGHT WE USE.  

METHODOLOGY: STUDENT-DRIVEN INQUIRY AND REPORTAGE.  

Expected from the student: assigned reading, discussions, written and presented analysis of outdoor lighting regs [international, state, local levels, each], final summary statement regarding the proposition.   Extra credit options available.

Research topic options:

__light & vision/perception                __health effects of artificial lighting                __environmental effects of artificial lighting

            __night sky viewing - relation to stress reduction as seen with "fractal pattern therapy"

__case study: proposal lighting regulation for city of Denver

            __ case study: class action lawsuit against DRCOG for LP damage

__additional ideas? -- see links at the Colo-IDA website for more ideas: http://www.darksky.org/ 

==================SUPPLEMENTAL INFORMATION=========================

Night sky symposium, Washington DC Feb.21-22, 2007: http://www.nightsymposium.org/ 

Colorado IDA website: http://www.coloradowestastronomy.org/ 

Excerpts from the Dec.2004 IDA Newsletter -- available online at http://www.darksky.org/

CIE Symposium on Light and Health --Vienna, Austria Sept. 30 - Oct. 2, 2004

This meeting, sponsored by Division 6 (Photobiology) of the CIE, covered both the positive and the negative impacts on human health. There were about 50 oral papers and many posters as well.  Meeting proceedings will be published by the CIE. Stay tuned to the IDA Web site (www.darksky.org) for news, and to the CIE Web site (www.cie.co.at). Here are just a few paper titles of special interest to IDA members:

· Introduction to the symposium, Wout Van Bommel (CIE President)

· The biological potency of light in humans: significance to health and behavior, George Brainard.

· Melanopsin and retinal ganglion cell phototransduction, Robert Lucas.

· Human circadian regulation, Stephen Lockley.

· Melatonin suppression by ocular light exposure during darkness and cancer growth, David Blask.

· Epidemiology of light at night work  and cancer risk, Eva Schernhammer.

· Ultraviolet and vitamin D: essential exposure, Ann Webb.

· Light and the aging eye, John Marshall.

· Exposure to the light-dark cycle in day and night workers, Marie Dumont.

· Spectral opponency in human circadian phototransduction, Mariana Figueiro and Mark Rea.

· How will light and health research affect electric lighting and lighting design?, Naomi Miller and Terry McGowan

· Photometric issues in healthy lighting research and applications, Jennifer Veitch

Here are only a few notes on the excellent meeting. Most of the talks were “enlightening” and thought

provoking.

Wout Van Bommel quotes and topics: Div 6 of the CIE deals with all aspects of optical radiation and lighting on plants, animals, and humans other than vision. Most of the impacts are photochemical, and hence there is a special interest in the ultraviolet and blue wavelengths, as that is where the energy is. Spectral power distribution (SPD) is important. It is a challenge to the CIE to understand these issues and to take them into account in lighting practice.  There are two“streams”, visual and biological.  Visual impacts mainly performance and emotion, while biological impacts health, both in positive and negative ways. Light and dark — darkness is just as important as light.

Some of the issues: Adaptation, spectral distribution, color, timing and duration of the light, time of day, energy use and costs, shift work, jet lag, physiology, psychology, medicine, neurobiology, chrono-biology, physics, and lighting practice (indoor and outdoor) all come into play and are important.

George Brainard: New discoveries will change our lighting practices. See also the new CIE publication (CIE number 158:2004) on Occular Light Effects on Human Physiology and Behavior, from TC 6-11. Light is a drug, and like all drugs, it can have very helpful effects, but it is a two edged sword and must be used appropriately. Light at night suppresses melatonin production and hence the circadian rhythm, to the detriment of health.  In today’s world, our days are often not bright enough and our nights not dark enough.  Light comes into the eye/brain system and is used in these two modes: visual and circadian. Several papers noted the recent discovery of new light sensors in the eye, separate from rods and cones, the new ones are the circadian sensors. Their spectral sensitivity is different from the rods and cones, with a peak sensitivity at about 480 nm. A well running biological clock in our bodies is critical to life in all its aspects. Our 24/7 lifestyle has potentially large negative impacts on a healthy life. 

Lockley and others talked about circadian phase shifting and entrainment, melatonin suppression, alertness, etc. Some of the main issues are the timing of light and dark, the intensity of the light, its duration, its pattern, the “history” of the light and dark, and the SPD of the light.

Here are a few conclusions:

· We need bright days and dark nights.

· Daylight gives us the blue and UV (be careful, not too much UV) light that we need.

· Especially needed in our offices.

· At night, avoid blue light and sleep in darkness.

· Critical for all, and especially for the elderly and those stuck indoors.

· Minimize problems from jet lag, shift work, and seasonal affective disorder (SAD) by proper application of light and darkness.

Cancer and Rhythm     Graz, Austria Oct. 14 - 16, 2004

An international conference of this topic was held in Graz, Austria, on Oct. 14 - 16, 2004, soon after the CIE symposium on Lighting and Human Health in Vienna (summarized above). The sub-title was: A new challenge in occupational medicine.

The abstract began: “Recently, evidence has been mounting that the disturbances of rhythms, in particular, circadian disruption, contribute significantly to the development of cancer.” [Note that these issues have been the subjects of papers at IDA meetings for some years now, with a number of the presenters in Graz attending past IDA meetings (as well as being active IDA members).] Titles of papers included:

· Health and Rhythms: Why life oscillates.

· Night-shift work and the risk of cancer.

· Shift work and the risk of cancer.

· Light at night, shift work, and breast cancer risk.

· Chronotherapy: The relevance of timing in the therapy of cancer.

· Photoreception for human melatonin regulation.

· Light in the built environment: role of circadian disruption in endocrine disruption.

· Circadian genetics of cancer.

· Tumors and melatonin.

· And many other oral and poster papers.

Naturally, in time, there will be a conference proceedings issued. We include here a short report on the meeting by Thomas Posch, the New Assistant IDA Europe Liaison Offi cer: William Hrushesky, in his talk on the infl uence of biological rhythms on cancer, pointed out that normal skin cells are not subject to mitosis during nighttime; neither are cancer cells. But during daytime, cancer cells grow 2-3 times faster than normal cells. This indicates that biological rhythms are essential for cancer development. Solar radiation turned out to have a strong infl uence on the cancer formation and growth rate, not only for skin cancer, but in general. Many kinds of cancer have their maximum formation rate in August (northern hemisphere).

Elizabeth Filipski talked on circadian disorder and cancer growth. She presented results of experiments with “jet-lagged mice”, i.e. mice that have been exposed to irregular rhythms of light and darkness. While mice without this artificially introduced circadian disorder show very regular curves of the blood temperature as function of the daytime, mice with circadian disorder have very irregular curves of the blood temperature as a function of time. Accordingly, the tumor growth rate in the jet-lagged mice is significantly larger than in normal mice. The conclusion is that chronic jet lag alters circadian physiology and molecular clock expression, but also accelerates tumor growth. (Note that chronic jet lag is just one particular form of circadian disorder.)

George Brainard gave a very interesting talk on “Photoreception for Human Melatonin Regulation: Relevance of Light Intensity and Spectrum”. He pointed out that already in 1987, the so-called “light/melatonin/cancer hypothesis” had been presented. However, in the 1980s, illuminance levels of about 2500 lux (!) have been considered as necessary in order to suppress nocturnal plasma melatonin production. By contrast, recent experiments showed that illuminance levels of about 1.3 lux are sufficient to suppress melatonin production, if the light source has a spectrum with a large output in the 446...472nm range, where the receptors regulating melatonin production are most sensitive. This is clearly a very important argument against bright (esp.“bluish”) artificial light at night. Five lux emitted at 460nm is affecting the melatonin production stronger than 68 lux at 555nm.

Richard Stephens talked about “Light in the Built Environment: Circadian Disruption in Endocrine Disruption”. He focused on the mechanism responsible for the regulation of the circadian rhythm. How does the pineal gland “see” light? Berson et al., in 2002, discovered intrinsically photosensitive retinal ganglion cells (ipRGCs) responsible for the regulation of the circadian rhythm (via melanopsin, not via rhodopsin). Stephens, too, pointed out that the action spectrum of the ipRGCS peaks in the blue, implying that quite low light levels suffi ce for melatonin suppression if the light source emits a significant fraction of its radiation in the lambda (<500nm) range.

Christian Bartsch went one step further and examined the question whether melatonin can be used as a drug to stop the growth of already formed tumors. Experiments with animals seem to indicate that this is indeed the case.  However, the time of melatonin treatment is very decisive. In the morning, for example, melatonin should not be used as a drug, since the body’s own melatonin production is then likely to get out of phase. Again, the circadian rhythmicity of melatonin production is the key. Christian Bartsch is author (together with his wife Hella Bartsch) of a textbook entitled Pineal Gland and Cancer-An Epigenetic Approach to the Control of Malignancy: Evaluation of the Role of Melatonin.

[end of report, additional news follows]

Night Light Suspected in Rise in Child Leukemia

--Patricia Reaney, Reuters News Service, London, UK:

According to a recent Reuters News Service article and echoed by a WebMD Medical News report, a “growing body of evidence” relating light at night (LAN) to an increased risk for certain types of cancer has now led researchers to believe that childhood leukemia may be among those types. According to scientists presenting research at the First International Scientific Conference on Childhood Leukemia in London, LAN has already been credibly linked to an augmented risk of breast and colorectal cancer. Although researchers are not yet making any bold claims, research continues and according to one scientist, “It is something we should look at and pay attention to.”  For more information go to: http://content.health.msn.com/content/article/93/102515.html

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2005 Sep 15 - 16: Yellowstone National Park, Wyoming, USA: IDA Fall Meeting

=====================================================================

Items from http://www.darksky.org/ homepage:

IDA's Lighting Code Handbook V1.14 Sep 2002

http://www.darksky.org/ordsregs/lchintro.html         http://www.darksky.org/ordsregs/odl-regs.html

• International Level Outdoor Lighting Regulations         U.S.A. State Laws Adopted and  Proposed

• U.S.A. Municipality Regulations Relating to Outdoor Lighting

By category:

  *Lighting Regulations     *Environment     *Education     *Images     *Information Sheets  

        *Fixtures/lamps     *Dark Sky Finder      *Light &Health     *Safety & Security   

=================================================================================================

TEACHING A COLLEGE COURSE ON LIGHT POLLUTION, 2003 March, by R.E.Stencel  2003AAS...202.1014S

Most introductory astronomy classes mention light pollution as a problem for observers of the night sky. Cursory coverage leaves students with an acquaintance of the problem, but they are rarely taught to recognize and deal with the practical aspects of energy waste, glare, trespass and choice of alternative lighting fixtures.

Recently, I ran a 10 week Honors seminar at the University of Denver entitled "Environmental and Social Consequences of Artificial Light" during winter term, 2003. The course was facilitated greatly by the suite of online materials available at the International Darksky Association website [www.darksky.org/resources/library.html], including the Lighting Code Handbook plus access to international, national and local lighting regulations and legislation. The students were assigned to review and summarize self-selected items by state, and present written summaries for in-class discussion purposes. We also had a guest lecture by a local IDA activist, Nancy Clanton, and considered involving other speakers from local CPTED and Planning departments. Slide mounted transparent diffraction gratings were distributed to help students observe spectra from different types of lights at night.

After the students learned what the problems are, and the basic remedies, student-driven inquiry lead to a number of fascinating questions that I hope will help them to remain aware and active in this arena. Details are posted hereafter, but some of the key points include: (1) To whom does the night sky belong? Are economic interests sufficient to justify invasion of one's dark space? (2) Do we accept disruption of our circadian rhythms in the name of 'progress', even if research now suggests linkage between melatonin problems and excessive levels of artificial lighting at night? (3) Does the loss of access to viewing the Milky Way pose risks to the imagination of younger generations? (4) Just because lighting is amenable to engineering solutions, does it merit attention in comparison with other pressing problems of our time?

In my opinion, the recent flurry of better lighting regulation is not enough, and dark skies will continue to be degraded, if we cannot convince our younger citizens of the need for vigilance and activism on this issue.

Please contact the author [rstencel@du.edu] for any discussion, comments and/or assistance needed in starting, or experiences related to, similar classes.

A copy of student essays and related material available on request. My thanks to the estate of William Herschel Womble, IDA and Ms. Clanton, for support that made this class possible.

IDA link                 AAS link

FYI, some of the relevant, early student written comments (excerpts, 1/22/03) based on study/reaction to Lighting Code Handbook, and IDA Info Sheet on Security Lighting:

…Section 4.10 concerning low pressure sodium lamps - damage due to misinformation claimed, but no details provided. --S.Anderson, Asian Studies
…Some of the solutions are rather costly. Where will these funds come from? Taxes? Donations? Either will require public approval. --M.Archer, Biology
…Not sure about total brightness per acre cap. Obviously a high rise apartment building will need more lighting than detached houses. --H.Bushkuhl, Media Arts 
…In Las Vegas, the window of my 15th floor hotel room was lit up by four sets of industrial size floodlights aimed up at the building. The glare was blinding, hindering my ability to see other casinos on the strip --
perhaps purposely. It was clear that any casino/hotel not competitive with lighting of others would not be seen. Would a dark spot on the strip attract business? If a maximum were imposed on all the casinos, they would have to be creatively competitive and energy use would fall considerably. Competitors could provide a natural enforcement mechanism. --P.Glazner, Comm.
…Had no idea there were so many types of lights. --K.Lampe, Psych.
…Max lumens per acre: would this allow larger, more influential property owners the majority of lumen allocation, leaving smaller businesses without adequate lighting? Exploitation? --R.Lee, Finance
…My grandmother had huge security lights around her house. My siblings and I would play a game where one person stands in front of the lights for a while and then tries to find the rest hiding in the deep shadows elsewhere around the house. The fun of it was how blind the seeker was, illustrating the steep transition zone. --L.Lieberman, Enviro.Sci.
…About the idea that lighting does not reduce crime, but just makes people feel safer: is this true? IS IDA presenting balanced information? --R.Losh, English
…The handbook did not address diffusion and reflection of light enough. Is only direct light useful, and only direct light problematic? Can reflected or diffused light be useful and/or problematic? Are there lights that can change their lumen output so as to adjust to the changing lighting situation (e.g. transition zones)? --N.Schafer, undeclared
…My biggest concern is that a code leads to more bureaucracy and government... --J.Stout, Physics
…What would a lighting code for a University look like? Would the University be responsive to such a concern? What would it take for a University to be responsive? How much impact would this
have? --K.Schlachter, Enviro.Sci.
…Darkness isn't as much a problem as adjusting to it from the light. Why are we afraid of the dark? We still have the use of our other senses. Lighting codes are treating the symptoms, not the problem: our
dependency on sight. --C.Wieder, Sociology
…In my hometown, there is a new prison that continuously lights up the sky for 20 miles around. I always have found bright lights annoying or excessive, but now I recognize the additional stress they cause on people and nature, like a larger epidemic. --K.Younger, English
[Students were mostly juniors and seniors, with majors as indicated.]

An example of a recent biomedical research result relevant to excessive lighting:

Artificial light at night may contribute to cancer risk, researchers say COOPERSTOWN, NY July 2001- The Bassett Research Institute at Bassett Healthcare has been awarded $1.2 million in grants by the National Cancer Institute and the Laura Evans Memorial Breast Cancer Research Fund of the Edwin W. Pauley Foundation to study the role of light during darkness as a risk factor for breast cancer progression. "Breast cancer incidence and deaths are considerably higher in industrialized societies than in developing countries but the reasons for such differences are unclear. Increased exposure to electric lighting at night may be one of those reasons," said David E. Blask, Ph.D., M.D., chief investigator for the studies and a research scientist in experimental neuroendocrinology/oncology at the Bassett Research Institute, along with Co-Investigator, Geroge Brainard, M.D. "This research will attempt to determine whether artificial light during darkness may be a contributing factor in breast cancer progression by eliminating the body's nighttime melatonin signal". In previous NIH-funded studies, Blask and his co-investigators Leonard Sauer, M.D., Ph.D. and Senior Research Specialist Robert Dauchy have demonstrated that melatonin inhibits, while light induced suppression of melatonin stimulates the growth of experimental animal tumors. "This newly funded research will take the next critical step and determine whether human breast cancers actually grow more rapidly when light-at-night shuts off melatonin production," Blask said. Life in modern societies has changed in numerous and profound ways from what it was prior to industrialization - one of those changes has been the exposure to electric lighting. Over time, humans have moved from experiencing dark nights and bright, broad-spectrum sun-lit days to modern built environments with relatively dim, limited-spectrum days and nights. An important aspect of good health is maintenance of the body's normal daily hormonal rhythms, particularly melatonin, which is produced every night by the brain's pineal gland. Evidence is accumulating that disruption of the melatonin rhythm produced by alterations in day/night cycles may lead to chronic fatigue, depression, reproductive abnormalities and perhaps even cancer. Millions of people in the United States and around the world take over-the-counter melatonin supplements primarily for sleep problems and jet lag. If electric lighting inside modern-built environments, including our homes, results in disruption of the nighttime melatonin rhythm, then the risk and growth of hormone-related cancers such as breast cancer may be linked to the intensity, wavelength and timing of the "new" lighting present in the modern built environment Population studies have shown that breast cancer risk is nearly 50 percent lower in blind women, with the reduction in risk of breast cancer correlating with the degree of visual impairment. These individuals have an intact melatonin rhythm and are presumably protected from the melatonin suppressive effects of light at night. Another recent epidemiological study demonstrated that women who work primarily at night, have a 50 to 70 percent increased breast cancer risk perhaps due in part to their exposure to light at night.

[END OF RECORD]