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Transcript of LIGHT POLLUTION Why proper outdoor lighting is important for communities and ecosystems. Steve...
LIGHT POLLUTION
Why proper outdoor lighting is important for communities and ecosystems.
Steve Pauley MD
Ketchum, Idaho
99% of the population in the lower 48 and the EU live in areas where the night sky is above threshold set for polluted status.
The Cost of The Cost of Throwing Away ElectricityThrowing Away Electricity
The USA spends over $1.5 billion per year in energy costs from wasted light.
= 6 million tons of coal or
= 23 million barrels of oil per year
Light pollution is the easiest kind of pollution to fix.
Reduce it, shield It, & shine it down.
Light the subject & hide the source.
Follow IESNA rec. levels.
Use IESNA minimums when can.
Light PollutionLight Pollution
Outdoor lighting currently stands as one of the most inefficient uses of energy today.
30 to 50% of all light pollution is produced by roadway lighting that shines wasted light upwards and outwards.
Light PollutionLight Pollution
We wouldn’t allow 30 to 50% of water from a hose to escape onto the pavement un-used. We wouldn’t run our electric heaters in winter with the windows wide open.
Light PollutionLight Pollution
Then why do we allow 30 to 50% of light photons from outdoor lighting escape into space?
We throw away electricity.
Three Million Years Three Million Years of Dark Adaptationof Dark Adaptation
The same eyes we have today allowed our ancestors to hunt at night by the light of the moon and stars.
Let’s be allowed to use our eyes at night.
Human Eye At Human Eye At NightNight
250 million years ago:
Evolution of the human eye’s binocular vision began with the appearance of mammals
Smaller noses and less sense of smell; Better eyes with acute vision and depth of field
Human Eye At Human Eye At NightNight
Two million years ago:
Early man huddled around the light of fires on the African savanna
790.000 years ago:
Homo erectus used fire to cook food (Middle East digs- 2004)
Human Eye At Human Eye At NightNight 150,000 years ago:
Homo sapiens used fire for cooking and warmth. They used the same eyes we have today to navigate, hunt, cook, eat, and give birth under the light of the moon and stars
20,000 years ago:Homo sapiens used shallow stone candles fueled with animal fat and with wicks of plant matter. Stone candles enabled stick figure art work on cave walls (France)
Evolution of Light PollutionEvolution of Light Pollution
3000 BC: first candles
Greeks, Romans through the middle ages: oil lamps
1784: hollow wicks used for brighter light
Early colonists: fish & whale oil lamps
Evolution Of Light PollutionEvolution Of Light Pollution
1800’s: kerosene lamps 1801: first electric lamp -carbon arc
lamp. Sir Humphrey Davy
1879: incandescent lamp. Thomas Edison & Sir Joseph swan
Evolution Of Light PollutionEvolution Of Light Pollution
1930’s: Mercury vapor (terrible beginnings) 1939: Fluorescent 1940: PAR lamps 1950’s: Tungsten Halogen
-------------The End of Night--------------------------------------- 1960’s: Metal Halide and HPS 1980’s Compact fluorescents (good – energy savers) 1990’s Electrodless (Induction) lamps 2000’s: Lighting designers run amok - laser shows; bridge
lighting; tower lighting; beacons on buildings
Thomas EdisonThomas Edison
Edison’s electric light in 1879 resulted, over time, in forming an industry dedicated to selling the public the idea that the more outdoor light, the better.
Today’s Lighting IndustryToday’s Lighting Industry
Harsh lighting is sold in the name of “security,” but more often it is used for advertising, and to sell bigger and brighter lighting fixtures.
It has proven to be a visual insult to the human eye, and has gradually stolen the night away.
Steve’s Fundamental Laws Steve’s Fundamental Laws of Light Pollutionof Light Pollution
First law:
Without local lighting ordinances, bad lighting gets progressively worse
Second law:
A. Light pollution is directly proportional to improvements in lighting technology, and
B. Inversely proportional to an awareness of the issues at the local level – city planners can reverse the trend
Steve’s Fundamental Laws Steve’s Fundamental Laws of Light Pollutionof Light Pollution
Examples:
Progressive eye insults beginning with incandescent bulbs, then HID lamps, then schemes to light up cities and bridges
The Enemy of Dark SkiesThe Enemy of Dark SkiesIs Horizontal LightIs Horizontal Light
The Battleground for light Pollution Centers on the Fixtures That Shine Light Just a Little Above the Horizon.
This Light Is Scattered the Most.
The Enemy of Dark SkiesThe Enemy of Dark SkiesIs Horizontal LightIs Horizontal Light
The battleground for light pollution centers on the fixtures that shine light just a little above the horizon.
This light is scattered the most.
Types of Light PollutionTypes of Light Pollution
GlareLight that beams directly into your eyefrom an annoying light fixture
Blinding glare: gas stations, theater effect
Disability glare: scattering of light – esp. elderly with cataracts
Discomfort glare: annoyance, fatigue – car headlights
Light Trespass
When light crosses property lines
The spillover of light where it’s unwanted and unneeded
Light trespass: a neighbor’s or a businesse’s unwelcome light can reduce the value of one’s property.
Types of Light Pollution Types of Light Pollution (cont’d)(cont’d)
Light confusion and clutter: too many
kinds of different fixtures and colors of light
Air pollution: greenhouse gasses from fossil fuel power plants
Can you find the “bad guy?”
Glare lighting does notallow the eye to see intothe shadows
This tree is “safe”
Original globes had soft, incandescent lights
Today’s globes andAcorns have glare producingHID lamps (hps, mh)
What Is Good Lighting?What Is Good Lighting?
It lights for the human eye using only the amount of light needed (follow the IESNA guidelines).
Good LightingGood Lighting It lights the subject and hides the light
source (lamp).
It provides adequate light for the intended task, but never over lights.
Good LightingGood Lighting
It uses fully shielded light fixtures.
It minimizes adverse impacts (light trespass) on adjacent property.
It uses high efficiency lamps while considering the color and quality as essential design criteria.
Luminance:
The perceived brightness measured in candelas/sq meter.
Illuminance:
The visual effect that luminance produces.Measured in Footcandles = lumens/sq footOr Lux = lumens/sq meter
IlluminanceIlluminance Foot-candles (fc)= lumens / sq foot. We use fc in the USA Lux = lumens/sq meter - metric
A local gas station’s lights peak at 270 fc = over 10,000 times the light from a full moon. The IESNA minimum safe light levels for an urban gas station = 10 fc; rural = 5 fc
Lighting ordinances should specify limits in lumens not watts
Lumens And WattsLumens And Watts A watt = one joule per sec., Or a current of one amp. Under
an electrical pressure of one volt. Idaho Power residential now about 6.5 cents/kwh USA’s avg. rate = 8 cents/kWh.
A lumen = a unit of luminous flux or a measure of the intrinsic brightness of a lamp. (An isotropic point source of luminous intensity of 1 candela emits one lumen into a unit solid angle of one steradian (sr), or 4 pi lumens on the spherical surface surrounding the point source).
. .
A Light’s Efficiency Is Measured inA Light’s Efficiency Is Measured inLumens Per WattLumens Per Watt
7700 watt incandescent bulb = 1,200 Lumens watt incandescent bulb = 1,200 Lumens
7070 watt high pressure sodium lamp = 6,300 Lumens watt high pressure sodium lamp = 6,300 Lumens
60 watt incandescent bulb = 60 watt incandescent bulb = 900900 Lumens Lumens
15 watt compact fluorescent Bulb = 15 watt compact fluorescent Bulb = 900900 Lumens Lumens
Lighting level limits are best expressed inLighting level limits are best expressed in lumens, notlumens, not w watts.atts.
All commonly used outdoor lamps todayAll commonly used outdoor lamps today (HPS, MH, LPS, MV) are over 1800 lumens. (HPS, MH, LPS, MV) are over 1800 lumens.
Light Sources, Watts, and Lumens
Source Watts Lumens Life Lu/W
Incandescent 100 1,690 750 hrs 17Tung-Halogen 300 6,000 2,000 20Comp. Fluorescent 26 1,800 10,000 70Merc. Vapor 175 7,900 24,000 45Metal Halide 100 8,075 10,000 81Metal Halide 400 36,000 20,000 90HPS 70 6,300 24,000 90HPS 250 26,000 24,000 90LPS 180 33,000 24,000 150
Street lights are on 4100 hrs/year.HPS & LPS lamps may last 5.8 yrs
Pole Heights and Lumen Limits
Pole Height Lumens6ft 400-1000 (Incandescent, PAR,8ft 600-1600 fluorescent, halogen)10ft 1000-200012ft 1600-240016ft 2400-6000 (begin HID lamps)20ft 4000-800024ft 6000-900028ft 8000-1200032ft 9000-2400036ft 12000-2800040ft 16000-32000
Useful Reference Levels for Useful Reference Levels for Foot-candle ValuesFoot-candle Values
1. Full moon .02 fc
2. Living room 10 fc
3. Sitting at my computer 12 fc
4. Schools 7.5 - 30 fc
5. AAA league baseball park 85 fc
6. Today’s gas stations 50 - 270 fc
7. Jewelers counter 400-800 fc
8. Operating table light 490 fc
9. Sunlight 10,000 fc
IESNA =
The Illuminating Engineering Society of North America.
Sets Minimum Foot-candle Levels Needed to Provide for Safety and Security for Specific Situations, I.E. Parking Lots, Walkways, Roadways, Gas Stations, Etc.
Full Cutoff ShieldingFull Cutoff Shielding
Essential remedy for glare and skyglow
No light rays from the fixture go above the horizontal
At least 90 percent of light is blocked in the near-sideways range from 0 to 20 degrees below the horizontal
Typical 175 w mvunshielded yard – barn light
$35 Sky Capshield placed to cut glare, trespass, & skyglow
More than meetsthe eye i.e. not justthe use of glare lighting.
More light does not =better security.
Security =effective, non-glare lighting.
SECURITY
Lighting and SafetyLighting and Safety
More light does not equate to better, safer light.
You can have less but more efficient lighting and not compromise safety at all.
Glare from poor lighting allows criminals to hide in dark shadows. Shielded, non glare lighting allows one to see in the shadows.
We’re not saying let’s turn out all the lights.
Lighting for security means effective, shielded, non glare lighting that meets the IESNA minimum light levels.
Lighting and CrimeLighting and Crime
A complex issue
No controlled study proves that more light decreases crime
More light does give people the feeling of more security
Lighting and CrimeLighting and Crime
Most crimes take place during the day
Two congressional crime task forces (1979 & 1997) found no relationship between lighting and crime. The studies that say there is a relationship are not controlled studies
“There are simply no good scientific studies that convincingly show the relationship between lighting and crime.” - (Ref - IDA information sheet 42; 4/98)
Crime Deterrents at Night:Crime Deterrents at Night:
Best: dog (pit bull?)
Next best: shielded, infrared motion detector flood lights combined with a video camera. Some schools have gone dark, used this system, and vandalism has decreased
Why an Ordinance? • Enhances the quality of life for all. • Sets a uniform code for all outdoor lighting.
Architects don’t need to guess whatwhat you want – saves them time andthe client’s $$$.
• Enhances safety and security by reducing glare• Reduces light pollution.
Without lighting ordinances, the bad practices of the last 100 years will simply escalate in the name of economic progress and “safety.”
12 Points For A Good 12 Points For A Good Lighting Ordinance Lighting Ordinance
1. Promote good lighting without compromising safety or security.
2. Convert street lights to level full cut-off fixtures. That can result in reduced lumen levels, lower wattage lamps, and a savings in electric bills.Can reflectors on posts be used instead of street
lights?
3. Address glare from unshielded flood lights.
4. Address light trespass. Use Kennebunkport formula, not light police.
H = 3 + D/3
5. Require that only the minimum IESNA lighting levels be reached for a given situation – follow the IESNA RP guidelines
6. Prohibit upward lighting of all types
7. Require signs to lit from the top down.7. Require signs to lit from the top down.
8. Educate all parties on what good lighting should be.8. Educate all parties on what good lighting should be.
9.9. Promote the use of motion detector lighting and timing Promote the use of motion detector lighting and timing devices. Suggest all non essential lighting be turned off devices. Suggest all non essential lighting be turned off by 11 PM. by 11 PM.
10. Allow local P & Z’s to require lighting for the 10. Allow local P & Z’s to require lighting for the human eye and safety using IESNA minimums, human eye and safety using IESNA minimums, rather than up lighting for trees, rocks, and rather than up lighting for trees, rocks, and buildings. Down light flag poles.buildings. Down light flag poles.
11. Never allow for more lighting than what is 11. Never allow for more lighting than what is really needed. Make lighting controlled, efficient, really needed. Make lighting controlled, efficient, and effective.and effective.
12. Enforce all lighting ordinances with 12. Enforce all lighting ordinances with finesfines..
Cost of RetrofittingCost of Retrofitting
Often recovered in three years. Depends on formula your utility company uses to bill for light pole maintenance.
San Diego is saving $3 million a year in power bills by retrofitting its street light fixtures to LPS.
Other BenefitsOther Benefits
Looks pleasant. Smooth, uniform illumination. Reduced glare is safer for motorists.
You can see pedestrians and objects more easily.
The elderly with cataracts are less affected by glare and will be safer drivers.
Light at Night and Light at Night and Human HealthHuman Health
Researchers have shown a definite link between exposure to light at night and lower melatonin levels – in all living things.
Light at Night and Light at Night and Human HealthHuman Health
Exposure to light at night = decreased melatonin levels. Mlt. Production is a circadian (light-dark cycle) driven event.
Nightly melatonin production by the pineal gland is needed for good health. Natural peak of mlt. = 2- 4 AM.
Retrospective Studies - Humans
• Totally blind women with no light perception to interfere with mlt. production have a roughly 30% less incidence of breast cancer.
• Shift workers have higher incidences of breast and •colon cancers ranging from 36% to 63%. Animal Studies
•Human breast cancer cells and rat hepatoma cancercells implanted in rats grow faster when the rats are exposed to light at night. Melatonin levelsare reduced by exposure to light at night.
• Breast cancer rates are highest in industrialized nations where night lighting levels are also the highest.
• Blask has now shown mlt. To be an anti-cancer hormone in humans. (Blask D; Gordon Conf. ’04)
• Nurses exposed to light at night had low mlt. Their blood was Infused into the rat – human breast cancer model and cancer cells increased their growth rates. Opposite effect for nurses kept in darkness at night (high mlt.)
• Nightly melatonin production in humans is beneficial to our health. Light exposure interferes with that.
Proposed Mechanism
80% of breast tissue has melatonin receptor sites.
High mlt. levels at night from exposure to LAN may allow mlt. to land on those receptor sites and block the uptake of linoleic acid (LA), a fatty acid that Blask measured in his rat experiments. Linoleic acid nourishes cancer cell growth.
Low mlt. (light) = more uptake of LA. = cancer growthHigh mlt (darkness) = less uptake of LA = cancer
growth rate drops 70%
“Light is a drug and that by abusing it, we risk
imperiling our health.”
Dr. Russell J. Reiter
University of Texas Health Science Center,
San Antonio, TX
Everybody Wins With Everybody Wins With Good LightingGood Lighting
Enhances the quality of life for all
No compromise to safety or security
Can save money
Less pollution
Everybody Wins With Everybody Wins With Good LightingGood Lighting
Less glare, light trespass & sky glow
Restores dark skies for stargazing
Prevents the pervasive spread of light pollution
Preserves the night skies for our children
Everybody Wins With Everybody Wins With
Good LightingGood Lighting
• Important to human health to sleep in darkness.
• Important to health of ecosystems to minimize exposure of plants and animals to light at night.
Ketchum Dark Sky Ordinance- 1999 Incandescent(w)Up to 260 lumens (20w) May be unshielded
260 – 1000 lumens (20-60w) No bulb showing; opaque top
1000 – 1800 lumens (60-120w) = *Floods
0ver 1800 lumens Must be full cutoff fixtures with no (all HID lamps) light above the horizontal----------------------------------------------------------------------------*Floods: Lights from 1000 - 1800 lumens: Must have shielding and opening may not tilt upwards more than 25 degrees from horizontal.Timers and motion sensors are encouraged.Motion sensors must go off in 5 minutes.
In Sept. 2001, Idaho Power completed the retrofit ofall drop lens street lights to these fco lights.
This has reduced glare, sky glow and light trespass without compromising safety.
Old drop lens light
Total Overkill. These should be compact fluorescentsAnd only 3 per side of the bldg.
This bldg. has 15 50 watt hps at 4000 lumens each,21 ft apart and 9 ft high. Ridiculous lighting.
15 50watt hpslamps 10 ft high,4000 lumens each,21 ft apart.
60,000 lumens oflight surrounding thebldg.
Overkill
Steve’s Modification of the Iroquois’Steve’s Modification of the Iroquois’ 7 Generations Principle7 Generations Principle
We should not pass through this life just to make our own lives We should not pass through this life just to make our own lives easier at the expense of our natural world and futureeasier at the expense of our natural world and future
generations of humans.generations of humans.
We are OF this planet, not unique to it. We are charged withWe are OF this planet, not unique to it. We are charged with acting as stewards of our natural world.acting as stewards of our natural world.
We must take actions today that better the lives of those who, We must take actions today that better the lives of those who, in 110 years, replace today’s entire population on earth.in 110 years, replace today’s entire population on earth.
Each of us can do just one small thing to better the lives of Each of us can do just one small thing to better the lives of those who will be here 110 years from now –i.e. preserve the those who will be here 110 years from now –i.e. preserve the night sky.night sky.