Light Pollution – Hawai’ian Islands 2003
Taken by Ed Lu (UH - IFA)
Astronaut on ISS for 6 months -2003
Quantifying Light Pollution
Worldwide
Defense Meteorological Satellite
Program (DMSP) USAF
Satellite and ground based
observations.
P. Cinzano, F. Falchi, C. D. Elvidge
U of Padova Dept of Astronomy
66% of the US population
and 20% of the world’s
population can no longer
see the Milky way.
X
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.
X
Light 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 Pollution
Glare
Light trespass
Sky glow
Energy waste
Clutter
Toronto 2003 – Sky Glow & Glare
During Blackout
After Blackout
Skyglow
Honolulu, HI
Can it be fixed? Yes.
How? With ordinances & one light at a time.
Courtesy M Donohue
Ranks as 5th
best observatory
in the world
Sky glow over Haleakala.
Note Hnl lights in NW
& darkness in SE
The Cost of
Throwing Away Electricity
The USA spends over $2 billion per
year in energy costs from wasted
light at night.
Waste:
= 6 million tons of coal or
= 23 million barrels of oil per year
Greenhouse gasses produced add to
global warming.
US Power Sources
55% from coal
22% from nuclear
10% from natural gas
10% from hydropower
2% from oil (Hawai’i 90%)
1% from other sources
Pineal Gland
Makes melatonin from
serotonin and tryptophan
Melatonin production responds
to light-dark cycle
Newly found circadian
Photoreceptors in RGC
Light & Human health
Circadian rhythms
Melatonin and the pineal gland
Newly discovered RGC’s (Berson-2002)
Blue light sensitive 464 – 480 nm
Trigger SCN – clock center – non visual
Rat studies (Blask – Basset Research Center, Cooperstown, NY)
LAN reduces mlt. and increases growth rates of human
breast cancer cells implanted in rats
Darkness at night – high mlt.; low cancer growth rates
Human studies (Blask – 2004)
Blood from humans exposed to LAN – low mlt; high cancer cell growth
Blood from humans exposed to darkness – high mlt; low ca growth
Epidemiology – cancers in shift workers (Harvard nurses health study)
(Stevens, Schernhammer)
Higher rates of breast and colorectal cancers in shift workers
Paper summarizing
current literature
linking LAN to breast
and colorectal cancer.
Medical Hypotheses
Oct. 2004
Effects of Artificial Light at Night
on Ecosystems (photopollution)
Paper summarizing
current literature
linking LAN to breast
and colorectal cancer.
Medical Hypotheses
Oct. 2004
Lighting 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)
In defense of low pressure sodium lights on Maui
Good for astronomers
Good for human health – no mlt. Suppression
Good for ecosystems
Good FCO Lighting In All Places
Recessed canopy lights
15 50watt hps
lamps 10 ft high,
4000 lumens each,
21 ft apart.
60,000 lumens of
light surrounding the
bldg.
Overkill
Good FCO Lights
Opaque cover diffuses
light better
Everybody Wins With
Good Lighting

Less glare, light trespass & sky glow

Restores dark skies for stargazing

Good for human health & ecosystems

Prevents the pervasive spread of light pollution

Preserves the night skies for our children
Everybody Wins With
Good 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.
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 mins as maximums
when can.

Design for low impact lighting.