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Light Pollution Glare Light trespass Sky glow Energy waste Clutter. 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.
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Light Pollution Glare Light trespass Sky glow Energy waste Clutter
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.
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
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
Recessed canopy lights Yes. Big Oil can do these canopies
50watt hps • lamps 10 ft high, • 4000 lumens each, • 21 ft apart. • 60,000 lumens of • light surrounding the • bldg. Overkill
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.