Citizens Restoring Congamond

June 13, 2017

Light Pollution

Just a little glare across the lake

from dock lights can distract from the

beauty of the nighttime tranquility

Direct and reflected rays diagram

Skyglow is caused by the downward scattering of upward light by air molecules and also

aerosols, mostly water droplets and dust. The longer the path length through the lowest part of

the atmosphere, the more the scattering. Light that goes straight up is mostly reflected, and has

shorter paths through the lower scattering layers. The low angle light is mostly directly radiated,

and it is this that causes most of the sky glow well away from the source.

Reflected

Radiated.

Air molecules

Aerosols

Sky Glow

Sky Glow Effects

Good Neighbor Dock Lighting –

Minimize Glare and Light Trespass

Solar Dock Light

Lowes

$35

Minimum

Dock Light

with no glare

Limit the Amount of Light -

Reduce Cost and Light Pollution

Excessive lighting

Requires More

Fixtures and Energy

Lower light levels will

reduce costs for

Fixtures, installation and

Energy – and minimize

Light pollution

Light Trespass

The use of unshielded light fixtures

which cause light and glare to

cross the property line.

Partial Fix for Reducing Light

Pollution: Use Shielded Fixtures

Shielded “Porch Lights”:

bulbs do not extend below shield

Adverse Environmental Effects

from Light at Night

Light Pollution and Wildlife

Wildlife concerns due to obtrusive light include:

Habitat Disturbance

Wildlife Behavior

Wildlife Survival

A Few Examples: • Artificial Light Contributes to an Estimated 100,000,000 Bird Deaths Annually in USA

• Artificial Light Contributes to Thousands of Sea Turtle Deaths Annually

Attraction/Repulsion

For frogs, a quick increase in illumination causes a reduction in visual capability from which the recovery time may be minutes to hours

After becoming adjusted

to a light, frogs may be

attracted to it as well

Light’s Effect on Communication

• Female glow-worms attract males up to

45 m away with bioluminescent flashes;

the presence of artificial lighting reduces

the visibility of these communications.

• The complex visual communication

system of fireflies could be impaired by

stray light

Light’s Effect on

Community Ecology

• Competition for times for foraging

• Increased Predatory Risk

• Ecosystem effects – long term changes

in the balance

How Light Affects…

REPTILES

Disorientation from artificial

lighting causes thousands of

hatchling deaths each year in

Florida and is a significant

marine turtle conservation

problem

Artificial lighting is extremely detrimental to many insect populations:

• disrupts normal flight activity

• long distance migrations

• attracts insects that don't normally move from their habitat.

• are effectively trapped by the light,

• they can be killed directly by lamp's heat

• they may circle the light until caught by predators, or

Distant sky glow may also disrupt their migrations.

Light traps are very likely changing the diversity of insects

If a particular species does not reproduce rapidly enough to make up

for the loss at the lights, it may disappear from the community.

For insects that are important as pollinators, or predators of nuisance

insects, their loss is detrimental to human communities as well.

INSECTS

• One third of all human food requires a pollinator

• Many plants and flowers are pollinated by nocturnal

insects or small animals, moths and bats

• Altering the lighting conditions at night can further

unravel our web of life which ultimately disrupts

our food sources

FLOWERS – POLLINATION

PLANTS

Leaves near the

Streetlight

remain on the

tree – even after

all other leaves

have fallen off

Parental Exposure to Dim

Light at Night Affects Immune

System of Offspring

Ohio State University study published March 31, 2017

finds hamster parents exposed to dim light levels prior

to mating can result in offspring with weakened

immune system.

http://www.nature.com/articles/srep45497

Long-term parental exposure to dim light at night (dLAN)

prior to breeding was sufficient to depress cell-mediated

immunity in offspring.

Parental dLAN exposure prior to conception is sufficient to

alter offspring immunological responses and embryonic

development.

This was the first study that connected dLAN exposure of

adults with a transgeneration impact on offspring

Additional Ohio State Research Findings

1. the secretion of several hormones that regulate the

day-night-rhythm or growth.

2. essential processes like reproduction, which are partly

influenced by light.

3. In commercial aquaculture continuous light is used to

enhance growth of fishes by inhibiting the sexual

maturation.

4. artificial light at night (light pollution) interferes with

several physiological processes in fish.

With Fish, Light can control

How Light in the water affects fish

Light can influence freshwater

food webs

Light can change predator-prey

relationships

Juvenile and other vulnerable

fish might retreat to overhangs

and reduce foraging efforts in

order to avoid predation

American Medical Association Recommended

CCT Limits for LED Streetlights – 3000K

June, 2016 as adopted by the AMA:

“That our AMA encourage the use of

3000K or lower lighting for outdoor

installations such as roadways. All

LED lighting should be properly shielded

to minimize glare and detrimental

human and environmental effects, and …

to utilize dimming for off-peak hours”

American Medical Association

Recommended CCT Limits for

LED Streetlights

• 3,000 K (Kelvin) maximum

• Currently offered by Eversource

• Advisory issued June, 2016

• Eversource offers standard 3000K

but will vary upon written request

Electric Lighting at Night and

Risk of Breast Cancer

by Susan Brink

October 16,

2000

by Janet Raloff

October 17,

1998 May, 2001, page 86:

“People should get a

dark night’s sleep”

February, 2003

“Blinded by the Light”

(Canadian Edition)

Nature, October 31,

2002, NEWS item

From the IARC, Lyon: Parkin, DM, et al. CA Cancer J Clin, 49:33-64, 1999

0 50 100

Japan, 1950s

Breast Cancer Incidence Per

100,000 women/year (age-adjusted)

{ U.S. &

W. Europe

Eastern Europe

Japan (Today)

Africa

China

Ways to Limit Light Pollution

- Use light sources with limited short

wavelength emission (AKA “Blue Light”

content)

• Use Motion Sensors – light only when

needed

• Use lowest amount of light sufficient for the

intended purpose

• Use Timers to avoid lighting all night long

Lighting Issues on Health and the Environment

International Dark Sky Association

www.darksky.org

• Leo Smith – contact at leo@smith.net

• Thank you!

Leo Smith – contact at

leo@smith.net

Thank you!