There is important information here. it is that night time lighting needs to limit the blue spectrum and not during the day. This is easily accomplished with our present technology. Our lighting is more and more plugged in in order to manage usage regardless and it is easy enough to establish hardware that can become time sensitive.
All this will support the human circadian rhythm. It may not seem like much but then why not?
Lighting has generally improved vastly and this last tweak is actually a bonus.
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The marvel of LED lighting is now a global blight to health
Light pollution is often characterised as a soft issue in
environmentalism. This perception needs to change. Light at night
constitutes a massive assault on the ecology of the planet, including us. It also has indirect impacts because, while 20 per cent of electricity is used for lighting worldwide, at least 30 per cent
of that light is wasted. Wasted light serves no purpose at all, and
excessive lighting is too often used beyond what is needed for driving,
or shopping, or Friday-night football.
The electric light bulb is
touted as one of the most significant technological advancements of
human beings. It ranks right up there with the wheel, control of fire,
antibiotics and dynamite. But as with any new and spectacular
technology, there are invariably unintended consequences. With electric
light has come an obliteration of night in much of the modern world;
both outside in the city, and indoors during what was once ‘night’
according to the natural position of the Sun.
Life has evolved for
several billion years with a reliable cycle of bright light from the
Sun during the day, and darkness at night. This has led to the
development of an innate circadian rhythm in our physiology; that
circadian rhythm depends on the solar cycle of night and day to maintain
its precision. During the night, beginning at about sunset, body
temperature drops, metabolism slows, hunger abates, sleepiness
increases, and the hormone melatonin rises dramatically in the blood.
This natural physiological transition to night is of ancient origin, and
melatonin is crucial for the transition to proceed as it should.
We
now know that bright, short-wavelength light – blue light – is the most
efficient for suppressing melatonin and delaying transition to
night-time physiology; meanwhile, dimmer, longer-wavelength light –
yellow, orange, and red, from a campfire or a candle, for example – has
very little effect. Bright light from the Sun contains blue light, which
is a benefit in the morning when we need to be alert and awake; but
whether we are outdoors or indoors, when bright, blue light comes after
sunset, it fools the body into thinking it’s daytime.
I expressed
the first serious concern about the potential health consequences of
electric light at night 30 years ago, when I asked whether over-lighting
might increase the risk of breast cancer.
It was during the 1980s, just as researchers were finding that a fatty
Western diet might not much alter the breast-cancer risk in individuals,
that a friend from the Fred Hutchinson Cancer Research Center in
Seattle pointed me to research on the impact of melatonin. Lowered
levels of melatonin (an effect of over-lighting) had been traced to
heightened levels of oestrogen (at least in rodents), a clear
breast-cancer risk factor when fatty diets were not. Later evidence has shown that women who work the night shift are at higher breast-cancer risk. Evidence suggests
that circadian disruption from over-lighting the night could be related
to risk of obesity and depression as well. In fact, it might be that
virtually all aspects of health and wellbeing are dependent to one
extent or another on a synchronised circadian rhythmicity, with a
natural cycle of bright days and dark nights.
Putting a finer point on the risk is ‘The New World Atlas of Artificial Night Sky Brightness’, published
in 2016. The atlas uses data from NASA’s Suomi National Polar-orbiting
Partnership satellite to estimate skyglow across the globe. The images
in the atlas are either dazzling or horrifying, depending on how you
look at it. In its coloured maps of cities and countries, using brighter
colours to show greater skyglow, Europe and North America appear
ablaze. According to the atlas, the Milky Way cannot be seen at night by
one-third of humans. In Europe, it’s not visible to 60 per cent of
people, and in North America, it’s a whopping 80 per cent.
The current ‘lightmare’ traces
back to the 1950s, when a road-building frenzy, including construction
of the Interstate Highway System, aimed to solve the problem of
congestion in the United States. But the roads turned out to increase
congestion and pollution, including light pollution, too. In retrospect,
the result was preordained: build a bigger freeway, and more people
will use it to the point where there is more congestion than before the
new road.
To understand the phenomenon, economists developed the
idea of induced demand – in which the supply of a commodity actually
creates demand for it. So the more roads one builds, the more people
drive on them, and the more that congestion results. In his book The Conundrum
(2012), David Owen eloquently extends the idea of induced demand from
larger roadways to the perils of increased efficiency in general. More
efficient energy-production and use, without concerted public education
on reduction of use, can make the pollution problem worse. He includes
the example of energy-efficient, and thereby cheaper to use, lightbulbs;
as people use more efficient lightbulbs, the total energy required to
burn them – along with light pollution – increases.
True to Owen’s tenet, a major report published in Science Advances
in 2017 showed that from 2012 to 2016 there has been a dramatic
increase in both the brightness of the metropolitan areas of the world
and the geographic extent of light pollution. This is despite the fact
that, since 2012, high-efficiency LED street lighting has been
increasingly installed in much of the industrialised world so as to
‘save energy’. But with overuse, it seems to be doing the opposite.
The
hyper-aggressive marketing of bright, white LED street lighting to
cities and towns has advanced to a breathtaking level. The US Department
of Energy (DoE) and a group of international partners have launched
an effort called ‘Rise and Shine: Lighting the World with 10 Billion
LED Bulbs’ in ‘a race to deploy 10 billion high-efficiency, high-quality
and affordable lighting fixtures and bulbs (like LEDs) as quickly as
possible’. Ten billion is more than the number of people on the planet.
In response to this relentless attack on night, the American Medical Association (AMA) stepped up and adopted
an official policy statement in 2016. I was one of the co-authors of
the AMA statement, in which my colleagues and I recommended reducing the
brightness and blue content of the LED products being deployed by
utilities around the country.
The reaction from the DoE and the
Illuminating Engineering Society of North America (IES) was swift and
highly critical of the AMA’s audacity, asserting that the AMA was not
qualified to make any statements on lighting. But this reaction
was disingenuous because without the AMA statement, the nationwide
retrofit would have continued unabated without regard to the environment
or human health.
Electric light can be a great benefit to people
when used wisely. To get to the ‘used wisely’ part requires all the
science happening now. But there must also be a desire for effective use
of electric lighting on the part of government and the public.
Recycling is now entrenched because children are being raised with new
awareness. Water conservation has also become important; few people will
leave the faucet running much longer than necessary. Yet some people
think nothing of using more electricity than they actually need.
LED
technology is not the problem, per se. In fact, LED will probably be a
large part of the solution because of its versatility. The issue in
street lighting is that the particular products being pushed by utility
companies and the DoE are very strong in the blue – and they don’t have
to be. Different LED products can be marketed that are much more
friendly to the environment and our circadian health.
This is of
paramount importance when lighting the inside of buildings where we live
and work.
In the life of the planet, destruction of night is as important an issue as the poisoning of water and air.
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