Light Pollution:
How Seeing the Stars will Save
You Money
and possibly save your life if you
are female
Dr. Harold Williams
Montgomery College Planetarium
located at the Takoma Park/Silver Spring
Campus
http://montgomerycollege.edu/Departmennts/planet
International Dark-Sky Association
What Is It?
• The Night Around Us.
– Our Communities.
• The Night Above Us. Dark skies.
International Dark-Sky Association
The Bottom Line on “Why”
• For a functional, comfortable, and
beautiful nighttime environment.
• For an environment friendly to:
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humans, including the aging eye,
wildlife,
plants,
the night sky.
International Dark-Sky Association
Where to light and when?
• Only where it is needed.
– Avoid obtrusive light.
– No wasted light or energy.
• Only when needed.
International Dark-Sky Association
How much light?
• The myth of The More the Better.
– Use IESNA or CIE recommended levels.
• Environmental lighting zones.
– Consider the location where you are.
• Use good transition lighting.
International Dark-Sky Association
North America at Night
International Dark-Sky Association
Poor security lighting,
using an old fashion 175 watt mercury fixture
International Dark-Sky Association
Almost a definition of light trespass, at an installation in
San Francisco, but could be in Silver Spring.
International Dark-Sky Association
Glare from a walkway light.
International Dark-Sky Association
Glare, luminance overload, bad transition lighting
International Dark-Sky Association
Why so much bad lighting ?
• Lack of awareness.
– Even in the lighting community.
– Builders, contractors, owners, operators.
– The public. Governmental staff.
• Apathy, or inertia.
International Dark-Sky Association
Keys to Quality Lighting
See the effect, not the source.
Shine the light down.
No glare!
Light only where and when needed.
Don’t over light.
Use energy efficient sources.
International Dark-Sky Association
Use of a full cut-off fixture for a parking lot
International Dark-Sky Association
A good antique (or period lighting) fixture, full cut-off
International Dark-Sky Association
Here is another good example,
using lighting fixtures with good control of the light output.
International Dark-Sky Association
So …
• It works, right? It’s common sense.
• Use only good lighting!
• Let’s fix the bad stuff!
• Educate everyone; build allies.
International Dark-Sky Association
Your Sixth Sense!
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Melanopsin
Suprachiasmatic nucleus
Pineal gland
Melatonin
Melatonin C13H16N2O2
Eye
Some demographic evidence
• Artificial lighting in the industrialized world:
circadian disruption and breast cancer by
Richard G. Stevens in Cancer Causes
Control (2006) 17:501–507
• LIGHT AT NIGHT CO-DISTRIBUTES WITH
INCIDENT BREAST BUT NOT LUNG
CANCER IN THE FEMALE POPULATION
OF ISRAEL in Chronobiology International,
25(1): 65–81, (2008) by Itai Kloog, Abraham
Haim, Richard G. Stevens, Micha Barchana,
and Boris A. Port
Some Other Issues
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Visibility
Safety and security
The aging and disabled eye
Human health, and animals and plants.
Energy
We all win!
International Dark-Sky Association
IDA
• The International Dark-Sky Association
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Newsletter.
Information sheets. Images. Slides.
CD’s, videos, and so on.
Web site: www.darksky.org
• Join IDA ! We need you.
International Dark-Sky Association
IDA’s Goals
• To preserve and protect the nighttime
environment and our heritage of darkskies through quality outdoor lighting.
• Membership based. Over 10,000
members, from all the states and 70
other countries. 500 organizations.
International Dark-Sky Association
International Dark-Sky Association
• 3225 N First Avenue
• Tucson AZ 85719 USA
• 520-293-3198
Fax: 520-293-3192
• ida@darksky.org
• www.darksky.org
International Dark-Sky Association
Recent State of Maryland movement for
good environmentally responsible lighting
• Maryland General Assembly Roadway Lighting Bill
HB816 new (very good legislation). The honorable
Alfred Carr email who introduced this house bill.
State Senator Jenny Forehand has introduced a
companion bill in the Maryland Senate: SB891 (some
more information on this bill, too).
• Maryland Outdoor Lighting Task Force Report from
2001 Maryland Outdoor Lighting Task force report.
Some good local Montgomery County
lighting laws that have not passed yet
• Outdoor Lighting Standards Established
Bill No. 4-07.pdf, not yet passed as far
as I can see.
• Zoning Text Amendment in Montgomery
County 07-01.pdf, not yet passed as far
as I can see.
• How come? If you can find out please
tell me!