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(meteorobs) OT - New slant on fighting light pollution



Greetings all,

The following article appeared in our weekend edition of the Globe and Mail,
Canada's national newspaper.  It gives a different slant on light
pollution... and perhaps a new argument to use in help fighting it.

- Cathy Hall
  Metcalfe, Ontario, Canada

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The following is an article from the globeandmail.com Web Centre.
 http://www.globeandmail.com

Blinded by the light

  The glow of city street lamps and office buildings that are fully
illuminated around the clock may be doing worse than interfering with
astronomers' telescopes. As The Globe's MARTIN MITTELSTAEDT reports, 'light
pollution' may also be causing havoc in the animal kingdom, and depression
and disease among humans. Could the unnatural death of darkness be hastening
our own?
Martin Mittelstaedt


 Every urbanite knows that the bright lights of the big city make it
impossible to see the stars in the night sky. What most of us don't know is
that those lights might also be making us sick.

The cause is light pollution -- the unearthly glow of billions of street
lamps, security and porch lights, searchlights, office lights and signs left
blazing as people everywhere try to dispel the limitations of the night.

For the first time, light is being investigated seriously as a human health
hazard, a possible contributor to the sharply rising incidence of breast
cancer, depression and other ailments. And for many wildlife species, light
pollution seems to be as grave an environmental threat as bulldozed habitats
and toxic-chemical dumping.

Until now, the loss of the natural night sky has been mourned mostly by
astronomers. But everywhere scientists look, they are finding that night
light is more complex than anyone imagined, and more insidious.

"People are beginning to take it much more seriously," said Alan Outen, a
British ecologist who has written extensively on the dangers of night
brightness. "I think we will look back on this as the aspect of pollution
that we have ignored, and I think its implications are far bigger than
people have ever really realized."

The ancient Greeks gazed up at night and saw in the planets and the stars
the gods and heroes of their legends. The dark sky has prompted poetry and
scientific inquiry, inviting each of us every night to ponder humanity's
place in the vastness of the cosmos.

But this new, transfigured night is something no living thing has
experienced before: For the first time in history, large populations are
growing up without the full, awe-inspiring canopy of a truly dark night sky
above their heads.

Because of the reflective properties of snow, Canadian cities are
particularly awash in light pollution. Some images of Earth from space show
that Montreal in winter outglows even New York City.

In a natural night sky, someone looking at the heavens with the unaided eye
should be able to see nearly 3,500 stars and planets, and the glow from the
Milky Way, our home galaxy. But in cities like Montreal or Toronto, the
number of visible stars has dwindled to about 50.

It's a stunning drop, one that has caused Canada's foremost astronomy
writer, Terence Dickinson, to lament, "It's now possible to grow up never
having been exposed to the natural beauty and inspiration of the night sky."

Nearly two-thirds of the world's population -- including basically everyone
in the European Union and the United States and 97 per cent of Canadians --
lives under night skies polluted by light, according to the first atlas of
the world's artificial night-sky brightness, published by Italian and U.S.
researchers last year.

In the most heavily urbanized regions of the world, it no longer ever really
gets dark at all. Satellite images reveal that night in eastern North
America, western Europe, Japan and South Korea has become a constant
twilight, an artificial dusk that lasts until sunrise. Seventy-seven per
cent of Canadians can no longer see the Milky Way.

The key author of the bright-sky atlas, Italian astronomer Pierantonio
Cinzano of the University of Padua, says his work "provides a nearly global
picture of how mankind is proceeding to envelop itself in a luminous fog."

The group also found that many people's eyes now never get to the stage
where they are fully adapted to darkness. Cinzano has calculated that about
one-10th of the people in the world, including 59 per cent of Canadians,
have lost much of their night vision.

Of course, there are still vast areas where the natural night sky exists.
But it is in places such as the Canadian Arctic, where almost no one lives.
For most Canadians, cottage trips and vacations to the north are the only
times they might see anything approaching a dark sky.

A hotel in Huntsville, Ont., outside Algonquin Park in an area with an
intact night sky, has even capitalized on the fact by opening an observatory
with a telescope so that guests can gaze at the heavens. The Grandview Inn
is the first resort-based observatory in Ontario, and Dickinson predicts
trips to see dark-sky areas will be "part of the ecotourism of the future."


     Remarkably, this dramatic transformation of the lightscape has taken
place in only a little more than a century. The invention of the
incandescent light freed people from smoky kerosene lamps and the fire risks
of toppled-over candles, and street lights made urban byways seem safer in
the evening.

Electric lighting liberated the night, invented nightlife, and altered our
whole approach to the day. The Biblical command of "let there be light" was
taken to heart with a vengeance.

Now, there is so much artificial light that it is blurring the boundary
between night and day, upsetting the delicate balance every organism uses to
navigate between bright and dark.

Some creatures appear to be highly susceptible to this disturbance, and for
them, night light can be a quick and efficient killer.

Lighting from modern office towers confuses migratory birds, which fly into
buildings lit up at night. Millions of birds are dying from these crashes.
In Toronto alone, the handful of big downtown skyscrapers injures or kills
about 3,000 birds a year, according to monitoring by the Fatal Light
Awareness Program, a local environment group.

Florida researchers have noticed since the 1980s that artificial light along
ocean beaches also confuses baby sea turtles. Statewide, more than a million
hatchlings are affected. The turtles instinctively crawl to the brightest
thing on the horizon -- normally the reflection of stars and the moon in the
sea. But where beaches are illuminated, baby turtles often crawl toward road
lights, where they are flattened by passing cars, or wander in circles on
the beach, unsure what direction to turn. Once day breaks, the exhausted
baby turtles bake to death in the hot sun.

The toll dismays those working to ensure the survival of the threatened
reptiles. "Sometimes the turtles end up on the road and crushed. We end up
with people crying and stuff like that," said Karen Moody, an environmental
specialist with Florida's Fish and Wildlife Conservation Commission.

Lepidopterists similarly blame night lighting for the decline in moths over
the past four decades. In a brief experiment by German researchers, more
than 42,000 bugs were collected at 19 lights in a rural area, showing how
easily artificial light can disorient insects. It can also cause mated male
mockingbirds to sing at night, when normally only unmated ones do, and stop
tree frogs from croaking, blocking a key courtship ritual.

Bryant Buchanan, a biology professor at Utica College of Syracuse University
in New York, has conducted experiments in which he showed that even the dim
light of a child's night light is enough to blind nocturnal frogs, impairing
their ability to hunt crickets.

He also observed that when a campus sports stadium lit up for nighttime
games, frog courtship stopped dead -- a worrisome development for animals
that may breed only a few nights a season and are subject to declining
numbers around the world.

"As dark habitat disappears, clearly if you're reducing the number of nights
that a frog can breed, year after year after year, that's going to have an
effect," he said.

Biologists say light at night has an effect similar to habitat loss. As
surely as development alters habitat, light can render an area unsuitable
for wildlife. As well, like many toxic compounds, light has the ability to
cause mental distress or impairment in vulnerable species.

Why the effect is so dramatic is not fully known, and may be different
depending on the species. But Outen said an intuitive explanation is
evolutionary: "Life on Earth evolved in the presence of alternating darkness
and light . . . and has adapted to it."

That's true of us as well. Sea turtles and birds are clearly in peril
because of light at night, but scientists have begun to study whether humans
may share something of the same fate.


     Richard Stevens, an epidemiologist at the University of Connecticut,
has developed the idea that light at night has the ability to disrupt
critical hormone levels that affect human health. Stevens came to this
conclusion while trying to solve the puzzle of why breast-cancer risk is
five times higher in rich, industrialized societies than in poor, developing
countries.

In the early 1980s, researchers speculated that the disparity might have to
do with fatty Western diets, genetics or the exposure to toxic chemicals,
explanations that have all been found wanting.

Stevens was working at a U.S. Department of Energy laboratory where studies
were being done on the biological effects of magnetic fields.
Serendipitously, he began thinking about electric currents and the fields
they produce.

"It occurred to me that a hallmark of industrialization is the use of
electricity," he said. "Then I got to thinking, 'What does that mean? How
can electricity cause breast cancer?' The most interesting aspect of
electricity is light, the light environment."

Stevens turned to the then-nascent scientific literature on circadian
rhythms -- the 24-hour biological clock that guides daily body functions --
and on melatonin, a critical hormone most living creatures produce only
while in darkness. Since then, he has been investigating night light,
developing the counterintuitive theory that something as harmless as a lit
light bulb can make people ill.

In a study Stevens co-wrote in 2001, he concluded that there is "mounting
evidence to suggest that disruption of the melatonin rhythm may lead to
chronic fatigue, depression, reproductive anomalies, and perhaps even
cancer."

Another study Stevens worked on last year presented the unusual discovery
that women who work graveyard shifts, such as nurses, have a substantially
higher risk of breast cancer. Even one all-night shift a week over a
three-year period was enough to increase the risk by 60 per cent.

He was impressed by other research that found breast-cancer risk to be
nearly 50-per-cent lower in blind women. The more a woman is visually
impaired, the lower the risk of cancer.

"How does light do it?" Stevens asked rhetorically. He thinks the key is
melatonin, he said, the hormone that has been popularized as an anti-aging
and anti-insomnia potion and as a cure for jet lag. "Melatonin is sort of
the chemical expression of darkness -- it's the 'Dracula' of hormones,
because it only comes out at night," he said.

Melatonin is produced in the brain's pineal gland, guided by cues from the
retinas of the eyes. Melatonin is produced only when the eyes signal that it
is dark. Production begins around nightfall, peaks in the middle of the
night between 1 and 2 a.m., and shuts off during the day.

This nightly dose of the Dracula hormone tells the body whether it is day or
night. Those who work under lighting at night, as in an office or a
hospital, might be inadvertently reducing the amount of melatonin they
produce. Experiments have shown that melatonin inhibits estrogen from
stimulating the growth of breast-cancer cells, among its other healthful
effects. This suggests why blind women, who presumably maintain high
melatonin levels, are at less risk, while night-shift workers are more
susceptible.

Researchers have been able to suppress melatonin production completely by
exposing people to light levels about five times brighter than in a typical
office. At lower light exposures, there is a less severe reaction, showing
that in some ways light is similar to carcinogenic chemicals such as benzene
or asbestos, with a given dose producing a set biological response.

A big question is whether the public is at risk from milder night light,
such as the artificial glow of the sky or even a neighbour's light shining
into a bedroom. In his research on shift workers, Stevens found that women
who reported sleeping in bright bedrooms -- where there was, for example,
just enough light pollution at night that they could read -- also had a
slightly elevated breast-cancer risk.

That finding suggests that light levels in major cities could be dangerous,
although the association was weak and it is too early to draw conclusions.
Still, Stevens said, people should take seriously anything that leads to
even a tiny change in the level of a critical hormone. "If you have a small
suppression of a hormone or a small elevation for many many years, it can
have a big impact."

David Blask, a scientist at the Bassett Research Institute in Cooperstown,
N.Y., became interested in melatonin after experiments showed that
pineal-gland extracts from cows or pigs injected into humans with cancer had
some improving effects. "It acts just like a roadblock, just like tamoxifen
in slowing down breast-cancer growth," he said.

Blask has been conducting research on rats, and has found that even a slight
amount of light at night shuts down production of melatonin in the rodents.
He made the discovery by exposing some rats to around-the-clock office
light, another group to normal alternating days of living under office
lights and nights of total darkness, and a third group to normal days, but
with a slight amount of nighttime light.

Surprisingly, the rats exposed to just a tiny amount of night light had the
same rate of tumour growth as the rodents exposed around the clock. "It
would be the equivalent to being in a completely dark room, with a small
light leak coming through a crack in the door. That's the light intensity
we're talking about," Blask said.

Luckily for humans, we're far less sensitive to light at night than rats and
other lower mammals, nocturnal species acutely attuned to melatonin for
reproductive reasons. But the magnitude and duration of their melatonin
surge at night are virtually identical to what happens in humans. Blask is
currently testing the melatonin hypothesis under a four-year grant from the
U.S. National Cancer Institute, trying to zero in on just how dim light has
to be before it no longer seems to stimulate cancer-cell growth.

There is much that scientists don't know about melatonin. Some individuals
seem to be far more sensitive to the night-light effect, and women appear to
be more vulnerable than men. At this point, Blask said, he wouldn't go so
far as to advise people to shut off their lights and sit in darkness for
health reasons. "But I think there is enough evidence right now to be
cautious at any rate and certainly limit our exposure to bright light at
night.

"When you think about it," he added, "light at night, except moonlight, is
pretty inappropriate. We didn't evolve with artificial light and it's only
been in the last 100 years or so that we've had this phenomenon of
artificial light."

Not only did people not evolve in illuminated nights, until recently they
also did not spend their days bathed in the weak lighting of the typical
office (about 200 times less bright than sunlight). To get in sync with
nature's rhythms, Blask said, "I think that people should have as dark
nights as possible, and as bright days as possible."


     Scientists studying light pollution have mostly been working in
isolation, and the evidence they have collected on its dangers has never
been drawn together. But a conference has been organized for next month in
Los Angeles that will gather many of the top scientists studying the impact
of night light to compare notes.

The conference, hosted by the UCLA Institute of the Environment and the
Urban Wildlands Group (a Los Angeles eco-activist association), could lead
to a higher public awareness of light pollution, according to organizers.
"In the ecological world, there are very few people who are looking at this
in a unified way," said Travis Longcore, a spokesman for the Wildlands
Group.

Longcore said light pollution should be receiving the same attention from
the public and regulators as other environmental ills. It has been growing
relentlessly by about 10 per cent a year since the 1960s, and only recently
have serious efforts begun to try to control it.

In Canada, the Ontario government has set up a nature reserve north of
Toronto, the first in the world where the preservation of a pristine night
sky was one of the reasons for establishing the park.

Located near Gravenhurst, the Torrance Barrens Conservation and Dark Sky
Reserve is just far enough over the horizon from Toronto and other major
Southern Ontario centres that its sky remains unpolluted.

Conservationists are hoping to expand the area of preserved night sky around
the park to include much of nearby Georgian Bay, the Bruce Peninsula and
Manitoulin Island, using municipal bylaws to restrict poorly designed night
lighting, the main culprit behind light pollution. If established, it would
be one of the largest areas in the developed world of protected night sky.

In the United States, the International Dark-Sky Association has also been
campaigning for the use of better-designed street and security lights that
won't spill into the night sky. The Tucson-based group views the light above
major cities as the glow of wasted energy. It has calculated that in the
United States, about $1-billion (U.S.) is spent annually on the electricity
wasted to illuminate the sky.

"We tell people all the time that that's just dollar bills burning," said
IDA executive director Dave Crawford. The group has championed bylaws
requiring "night-friendly" lights, with the bulb recessed into the fixture
so that its light does not glare out horizontally or upwards. Unlike the
common cobra-head street lamp, lamps that direct a tight beam at the ground
use less wattage and save money because they don't uselessly light the sky.

Well-designed lighting can help recover the sky. In Tucson, where night-sky
protection rules exist, Crawford said, "on good nights you can actually
detect the Milky Way. Remember, this is a city of 800,000 people, whereas in
an average town of 50,000, you couldn't do that. So we know these things
work."

The association also urges neighbours to complain to those guilty of
committing "light trespass" -- lamps on at night whose light intrudes on the
properties of others -- and criticizes around-the-clock security lighting,
urging people to use motion-activated lights instead to deter crime.

But where people like Crawford see the planet developing a global lighting
problem analogous to global warming, others love night lighting, especially
some business interests.

In Langley, B.C., city council passed a bylaw last year restricting the use
of night-piercing searchlights to 30 evenings a year, after public
complaints over light from a new Famous Players "Colossus" movie theatre.
While many residents complained that the company was engaging in "celestial
vandalism," Famous Players managers thought that the lights lured customers,
and they launched court action against the bylaw.

No one seems to like high lighting levels more than big-box retailers. Many
now use three times the intensity of shopping-mall lighting in the 1970s.
"There is a lot of desire to boost up the light levels," said Tony
Rutenberg, sales manager at Rutenberg Sales Ltd. of Mississauga, a major
Canadian lighting dealer. "It looks very inviting." The big-box retailer
thinks, " 'I'm going to have more people come in,' " he said.

Rutenberg has tried to encourage retailers and other big lighting users to
consider sky-friendly products. He tells them it's a money-saving bet in the
long run because they use less electricity, while curbing light pollution.
"With better design, you absolutely can reduce your energy, lower your
costs, and save the sky," he said.

While the health and environmental impacts of light pollution are starting
to capture attention, Crawford of the Dark-Sky Association has other
concerns. While he, too, worries that lights may be making people sick and
harming wildlife, he said the fading of the heavens could also cause a
fading of the human imagination -- in many ways, a greater long-term threat.

Writers and other artists have always drawn inspiration from the night sky.
"We had the sky up there, all speckled with stars and we used to lay on our
backs and look up at them and discuss about whether they was made or only
just happened," Mark Twain wrote in Huckleberry Finn.

"There have been poems and symphonies and music and art, and van Goghs and
other [masterpieces] all done with the stars up there," Crawford said.
"Nobody's done painting like this about street lights or billboards. It's
the glamour and wonder of the universe we live in. We've got to preserve
that."

If humans can't solve a relatively easy pollution problem, like excess night
light, Crawford added, it doesn't bode well. "We're going to lose the Earth
eventually because as we lose touch with the environment around us, both the
day and the night. We become insensitive to it, and before long, nature kind
of rises up and stomps us."


Copyright (C) 2001 Globe Interactive, a division of Bell Globemedia
Publishing Inc.
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