[DSLF] Digest Number 1815

[DarkSky-list@yahoogroups...]

There are 5 messages in this issue.

Topics in this digest:

      1. Light at night-cancer risk in humans verified
           From: Stephen Pauley <spauley2@cox...>
      2. RE: Light at night-cancer risk in humans verified
           From: "Greg Crawford" <gc@nelsonbay...>
      3. Unfortunate Christmas surprise!
           From: "reflector32" <francisparnell@hotmail...>
      4. Re: Unfortunate Christmas surprise!
           From: "Mike J. Shade" <mshade@theriver...>
      5. I've fallen and I can't get up
           From: KDConod <kdconod@yahoo...>


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Message: 1         
   Date: Fri, 02 Dec 2005 15:18:34 -0700
   From: Stephen Pauley <spauley2@cox...>
Subject: Light at night-cancer risk in humans verified

Dark Sky Warriors:

David Blask, Bud Brainard and colleague's paper on human exposure to 
light at night has finally been published in the Dec. 1, 
1005  journal, Cancer Research.


Melatonin-Depleted Blood from Premenopausal Women Exposed to Light at 
Night Stimulates Growth of Human Breast Cancer Xenografts in Nude Rats

David E. Blask1, George C. Brainard2, Robert T. Dauchy1, John P. 
Hanifin2, Leslie K. Davidson1, Jean A. Krause1, Leonard A. Sauer1, 
Moises A. Rivera-Bermudez3, Margarita L. Dubocovich3, Samar A. 
Jasser2, Darin T. Lynch1, Mark D. Rollag4 and Frederick Zalatan1
Cancer Research 65, 11174-11184, December 1, 2005

The studies are the very first to show a direct link between the 
cancer stimulating effects of human exposure to bright white light at 
night (280 fc) via melatonin suppression IN HUMANS - using HUMAN 
blood.  Previous studies in Dr Blask's lab have been with rats and 
rat blood only.  This is the closest we'll come to proving that 
exposure to bright white light at night is a cancer risk in 
humans.  What remains are similar studies to see where the lower 
illuminance level limit is to cause this effect and which colors 
(spectra) of all the different outdoor and indoor lighting sources 
are the least harmful to humans?

 From the abstract:
"These results are the very first to show that the tumor growth 
response to exposure to light during darkness is intensity dependent 
and that the human nocturnal, circadian melatonin signal not only 
inhibits human breast cancer growth but that this effect is 
extinguished by short-term ocular exposure to bright, white light at 
night. These mechanistic studies are the first to provide a rational 
biological explanation for the increased breast cancer risk in female 
night shift workers."

See full abstract:
http://cancerres.aacrjournals.org/cgi/content/abstract/65/23/11174

One criticism of Dave's previous studies often centered on "well, 
that's just for your rats, what about humans?"
Now we know for sure that melatonin is a cancer preventive hormone IN 
HUMANS and melatonin needs to be produced by the pineal gland at 
night without interference with intrusive bright lights. It also 
presents a very plausible cause for the higher incidences of breast 
and colo-rectal cancers in shift workers.

Future research needs to answer these questions:
Where is the lower limit of illuminance  causing this effect?
Do all light colors create this harmful effect or is it with white light only?
The melatonin suppressive effects caused by indoor bedroom lighting 
sources must also be studied in humans.

Lessons from this study:

All lighting designers and engineers MUST pay attention to
these findings.  Exposure to light at night is definitely a public health risk
for humans.  Light exposure during the early morning hours must
be thought of as a potentially harmful environmental health hazard.
In this sense, light acts like a drug and must be used responsibly.

Using the precautionary principle, it means eliminating exposures of
all outdoor color sources via light trespass into bedrooms.  It means
educating night shift workers to develop a sleep-wake cycle that
requires a sleeping mask and a dark room while shifting their
circadian clocks to a new light-dark cycle.  It means cautioning
the public to sleep in total darkness - especially those who are fighting
cancer.

It means that the lighting industry has a public health responsibility
to promote the use full cutoff lights in residential zones and in cities where
hotels, motels, and apartments have bright lights shining into
bedrooms.  Not everybody closes their curtains and many sleep
with white light exposure from TV and computers still on in their bedrooms.

Any model lighting ordinance (mlo) that is produced by the IDA, the
IESNA, or the two organizations combined, MUST take these human
light-melatonin-cancer studies into account.

The currently proposed IDA mlo does NOT and must be changed
to protect the public's health.  Any compromising on this
would be irresponsible.

Please see my 2004 paper on this subject posted the IDA's photobiology/
light and health section:   http://www.darksky.org/links/pauleylhh.pdf


Lighting for the human circadian clock: recent research indicates 
that lighting has become a public health issue

Stephen M. Pauley<mailto:spauley@cox-internet...>
[]

<http://www.sciencedirect.com//science?_ob=JournalURL&_cdi=6950&_auth=y&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=11dee3e9b445a1867f511bb8df725abe>Medical 
Hypotheses<http://www.sciencedirect.com//science?_ob=JournalURL&_cdi=6950&_auth=y&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=11dee3e9b445a1867f511bb8df725abe> 

<http://www.sciencedirect.com//science?_ob=IssueURL&_tockey=%23TOC%236950%232004%23999369995%23514479%23FLA%23&_auth=y&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=95bf68263f1417ada80f4d6b4fa91819>Volume 
63, Issue 4 , 2004, Pages 588-596

Thank you,
Stephen M Pauley MD FACS
Ketchum, Idaho
spauley2@cox...



[Non-text portions of this message have been removed]



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Message: 2         
   Date: Sat, 3 Dec 2005 10:09:00 +1100
   From: "Greg Crawford" <gc@nelsonbay...>
Subject: RE: Light at night-cancer risk in humans verified

>David Blask, Bud Brainard and colleague's paper on human exposure to 
>light at night has finally been published in the Dec. 1, 
>1005  journal, Cancer Research.

Wow! I thought Kepler was a Renaissance genius, but here we have
ground-breaking stuff from a thousand years ago. ;-)

- Greg




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Message: 3         
   Date: Sat, 03 Dec 2005 19:39:39 -0000
   From: "reflector32" <francisparnell@hotmail...>
Subject: Unfortunate Christmas surprise!

As we all know, light is not a magic force field.  It has not been 
shown conclusively that bright, glary lighting deters crime.  And it's 
unfortunate that utilities convince their customers to install NEMA 
fixtures for security.

I found out this morning, Dec. 3rd, between midnight and dawn, a friend 
and her husband had a large Christmas display--consisting of a 4-foot 
diameter clear plastic bubble with figures inside and snow falling-- 
stolen from their front yard.  The ironic thing is that the display was 
only a few feet from a NEMA 100-watt HPS "yard light" that was recently 
installed.

It looks as if my friend was a "victim" of the utilities propaganda 
about outdoor lighting making us safer and more secure!

Francis Parnell   





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Message: 4         
   Date: Sat, 03 Dec 2005 12:52:58 -0700
   From: "Mike J. Shade" <mshade@theriver...>
Subject: Re: Unfortunate Christmas surprise!

Oh, simple explanation, if they had TWO lights, this never would have 
happened (kidding of course)...

At 12:39 PM 12/3/2005, you wrote:
>As we all know, light is not a magic force field.  It has not been
>shown conclusively that bright, glary lighting deters crime.  And it's
>unfortunate that utilities convince their customers to install NEMA
>fixtures for security.
>
>I found out this morning, Dec. 3rd, between midnight and dawn, a friend
>and her husband had a large Christmas display--consisting of a 4-foot
>diameter clear plastic bubble with figures inside and snow falling--
>stolen from their front yard.  The ironic thing is that the display was
>only a few feet from a NEMA 100-watt HPS "yard light" that was recently
>installed.
>
>It looks as if my friend was a "victim" of the utilities propaganda
>about outdoor lighting making us safer and more secure!
>
>Francis Parnell
>
>
>
>
>
>_________________________________________________
>To subscribe to the DarkSky List Forum send email to:
>DarkSky-list-subscribe@yahoogroups...  or visit:
>
>http://groups.yahoo.com/group/DarkSky-list/join
>
>Help save your town from obtrusive lighting --
>Invite your Planning and Zoning department and
>local officials to join us!  Please visit the IDA & CRL
>websites at http://www.darksky.org and
>http://www.crlaction.org frequently, too!
>Yahoo! Groups Links
>
>
>
>

Mike J. Shade: mshade@theriver...
Director, Sonoita Hills Observatory, Sonoita Arizona
www.sonoitaobservatories.org

See work done at the observatory: http://c3po.cochise.edu/astro
under the "images & photos" panel on the left of the page

Fight wasteful and obtrusive outdoor nighttime lighting:
International Dark Sky Association:  www.darksky.org

"I like the dark, it's cheap."  Ebinezer Scrooge  




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Message: 5         
   Date: Sat, 3 Dec 2005 12:04:07 -0800 (PST)
   From: KDConod <kdconod@yahoo...>
Subject: I've fallen and I can't get up

Here's an interesting example of poor lighting -
in this case indoor lighting.

My wife and I went to Atlantic City last weekend
and went to see a show at one of the casinos. As
we entered the theater I noticed that they had a
set of giant white spotlights pointed at the
audience. The glare was really uncomfortable and
made it difficult to find our seats.

I wasn't the only one, as evident by watching the
squinting audience filing into the room. The
glare was so bad that behind us an older woman
took a tumble down a flight of stairs. She really
could've been hurt but fortuantely she was OK.

People are so stupid: more is always better seems
to be the rule of the day.



Kevin Conod
kdconod@yahoo...


		
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http://www.yahoo.com/r/hs


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Help save your town from obtrusive lighting --
Invite your Planning and Zoning department and
local officials to join us!  Please visit the IDA & CRL
websites at http://www.darksky.org and 
http://www.crlaction.org frequently, too!
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