Agenda Item # 10.1 - Dr. Paul D. Lynam | Received 03/14/2023From:plynam
To:Mayor Marie Blankley; Council Member Rebeca Armendariz; Council Member Dion Bracco; Council Member Tom
Cline; Council Member Zachary Hilton; Council Member Carol Marques; Council Member Fred Tovar; Cindy
McCormick; City Clerk; Sharon Goei
Subject:EXTERNAL - Appeal of Planning Commission’s February 2, 2023 Denial of Ordinance Change (Project Number: Z
18-04)
Date:Tuesday, March 14, 2023 12:59:51 PM
Attachments:Gilroy_Council--PLynam_2023-03-14.pdf
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Honorable Mayor and City Council,
Please find attached a written comment regarding the Council's
forthcoming (20 March 2023) deliberations regarding the City of Gilroy's
Planning Commission denial of ordinance change (Project Number: Z
18-04).
The City Council is implored to respect the considered judgment of
their expert panel of advisers, the Planning Commission. Please seize
this opportunity to abide by the intentions of the City’s own guiding
principles. Deny the ordinance change
Yours faithfully,
Dr Paul D. Lynam
Astronomer
University of California Observatories/Lick Observatory
UCO/Lick Observatory
7281 Mount Hamilton Road
Mount Hamilton
CA 95140
14 March 2023
Honorable Mayor and City Council,
Appeal of Planning Commission’s February 2, 2023 Denial of Ordinance Change
(Project Number: Z 18-04)
1. Introduction
The appeal (by only one or two commercial interests) of the Planning Commission’s 2 February 2023 denial
of ordinance change seeks, in eect, to overturn an ordinance which has served the entire population of Gilroy
(and its hinterland) well for decades. In suppressing Light At Night, LAN (a.k.a. light pollution) the existing
ordinance is arguably more needful today than when rst introduced. Further, the appeal eectively asks that
the City of Gilroy deliver a monopoly into the hands of those same commercial interests | a move which in due
course may see the City challenged in the courts by competitors. This is the latest episode in the proliferation
of light-polluting digital billboards (and the large quantities of blue-rich light emitting diodes, LEDs they utilize
over large surface areas) along the highway 101 corridor. Over the past ve years, ordinances have been modied
to allow new electronic billboards in the City of San Jose, Norman Y. Mineta San Jose International Airport,
the City of Santa Clara and elsewhere in the South San Francisco Bay Area.
LAN: It’s happening. It’s outdoor LEDs. We’re sure. It’s bad (and getting worse). We can x it 1 .
In addition to concerns of visual blight, the environment, climate and public health, this regional trend of
accelerating light pollution threatens to impact the University of California Observatories’ Lick Observatory
(UCO/Lick) and its mission.
As stated in previous submissions (e.g. Lynam 2022) UCO/Lick has no wish to crusade in pursuit of the ideal of
having no illuminating sources at all. A higher aspiration is to sustain the rapport and understanding between
neighboring communities and observatory that has endured since the 1870s.Responsibly and sensitively installed
billboards may confer benets to the community. However, over nearly two years, Lick Observatory’s advocacy
(beginning with Lynam 2021), recommending that Gilroy incorporate the International Dark-Sky Association,
IDA guidance for Electronic Message Centers2 (2019) into the ordinance has been consistently rebued.
The appeal dismisses, disregards and denies:
1.The City of Gilroy’s guiding principles, outlined in its 2040 General Plan3 advocating:
measures to limit light pollution from outdoor sources.
2.The ndings of the City of Gilroy’s own panel of experts, in the form of the Planning Commission which,
after considered assessment:
(a)Found the Initial Study/Mitigated Negative Declaration (IS/MND) inadequate, and
(b)Denied the ordinance change.
1 Mantra borrowed and modied with apologies to Nicholas (2021)
2 https://www.darksky.org/wp-content/uploads/2019/05/EMC-Guidelines-IDA2019-1.pdf
3 https://www.cityofgilroy.org/274/2040-General-Plan
3.Examples from other Californian local authorities whereby the City of Gilroy could achieve a better deal
than prescribed by the appellants (e.g. imposing illuminated sign hours of operation; incentivizing billboard
relocation and take-down; requiring a guaranteed minimum revenue).
4.That blue-rich LED technology deployed in outdoor lighting devices (such as digital billboards) contributes
disproportionately (via a number of mechanisms) to LAN and renders a deleterious impact on the activity
of Lick Observatory. In recent years, as witnessed from Mount Hamilton (and elsewhere), the rate of
increase in sky background has accelerated (predominantly resulting from scattered light emanating from
settlements along the Highway 101 corridor). This erodes researchers ability to detect astronomical
sources, compelling longer exposure times, thereby reducing the eciency of an institution that began
continuously contributing to science just twelve years after Gilroy was incorporated.
5.Recommendations to adopt guidelines to minimize damage to dark skies, developed by the IDA. Experience
shows that adoption of the full set of IDA guidance does not deter outdoor media companies’ eorts to
deploy new-technology billboards. That the proposal for digital billboards to be placed in Gilroy has
consistently rebued these recommendations is, in this writer’s experience,extraordinary.
6.The pleas of Public Health researchers to minimize LAN. Multitudinous, independent, scientic, peer-
reviewed studies, published throughout the last 30-plus years, have identied links between LAN and
circadian disruption (a.k.a. Daily Rhythm Disruption) to behavioral changes, sleep disorders, diabetes,
depression, obesity, heart disease, Mild Cognitive Impairment, MCI (a transitional phase between normal
aging and dementia) and cancers of the breast, prostate, colon and rectum. Of the above-listed maladies,
the last four now have,multiple, well-established causal connections between those cancers and LAN.
Such studies implore:
policy-makers should take eective measures to curb the surging light pollution at night.
| Chen et al. (2022)
and,
immediate measures should be taken to reduce articial light at night .
| Al Nagger & Anil (2016)
and,
Regulations on nighttime advertising (which is virtually non-existent today) should
also be implemented and switching o such illumination can contribute to the most
important aims of decreasing light pollution [...]Public policy makers should also
be convinced to curb the wide scale introduction of short wavelength [i.e. blue-rich]
illumination.
| Haim & Portnov (2013)
7.Objective, informed and expert opinion | unmotivated by commercial interests | delivered in good faith
and with genuine concern, by national and international organizations (e.g. American Medical Association;
Sleep Foundation; World Health Organization, WHO; www.breastcancer.org).
8.Environmental and other concerns expressed by advocacy groups (e.g. Audubon Society; Sierra Club; No
Digital Billboards San Jose).
9.The majority of independently gathered public comment (including Gilroy residents and those from ‘out-
of-town’).
A document central to the present appeal is a (17 February 2023) letter from Hanson Bridgett LLP, representing
Outfront Media Inc. (Marciniak & Dao 2023, hereafter MD23). Much of the following addresses statements
made therein.§2 discusses the impact of LAN upon UCO/Lick.§3 (and appendix) discusses LAN and human
health,§4 discusses LAN and the City’s General Plan,§5 discusses Regional proliferation of LAN,§6 deals with
allusions to those from ‘out-of-town’,§7 provides conclusions. References are appended.
2. Light At Night, LAN (a.k.a. Light Pollution) and the University of California Observatories/Lick
Observatory, UCO/Lick
UCO/Lick endorses the sentiment to:
encourage the City to rely on the science-based analysis. | MD23
Since before the 1970s, the growth of LAN has increasingly negatively impacted Lick Observatory’s operation and
mission. In visible light, LAN chiey results from the physics of photon scattering by ever-present atmospheric
aerosols (e.g. water vapor, particles). Scattering is responsible for twilights, renders clear daytime skies as
blue and cloudy skies as gray. Applying the physics of aerosol scattering to model sky brightness arising from
lighting use can be enormously complex. A physical model describing light pollution via interaction of articial
light with the atmosphere was developed by Garstang throughout the 1980s. Garstang (1989a) includes some
simplifying assumptions and is the most widely-adopted description. Using Garstang’s model, Duriscoe et al.
(2018) quantify the eects of metropolitan light impacting astronomical sites up to 200{300 km away. Beyond
highlighting the observation of increasing LAN as witnessed from Mount Hamilton (as well as in the vicinity of
most conurbations in the industrialized world),multiple independent scientic studies, published in peer-reviewed
journals, have been previously cited (Lynam 2023), not merely describing, but quantifying the acceleration of
LAN and its eect on observatories | including, specically, Lick Observatory (e.g. Green et al. 2022).
However, in attempting to refute mature science, MD23 exhibit a rst instance of failing to introduce any
scientic article | or even empirical evidence. Therefore, MD belie the sentiment to ‘rely on the science-based
analysis’. In the absence of any scientic foundation , MD23 meekly proer the conjecture that scientists have:
misused existing studies. | MD23
Those, supposedly ‘misused’, studies nd that:
Eighty per cent of children born in the western world today will never know a night dark enough
that they can see the Milky Way. | (Bogard 2013)
Mount Hamilton remains one of the few locations in the San Francisco Bay Area where one can observe the
Milky Way with the naked eye. However, the acceleration of light pollution is diminishing those opportunities and
eroding researchers ability to detect astronomical sources, compelling longer exposure times and thus reducing
eciency.
The United Nations has declared:
An unpolluted night sky that allows the enjoyment and contemplation of the rmament should be
considered an inalienable right of humankind equivalent to all other environmental, social,
and cultural rights. |- (Bogard 2013)
This declaration was not addressed in the Initial Study/Mitigated Negative Declaration, IS/MND.
UCO/Lick has never sought to belabor local authorities with the special interests of observatories, astronomers
and/or dark-sky advocates. It is acknowledged that the astronomical community’s desire to halt (or even
reverse) the pervasive regional encroachment of LAN represents the special interests of a minority group. There
are more powerful arguments opposing the introduction new sources of LAN. It would be redundant to discuss
concerns of blight, driver distraction, and impacts of LAN on fauna and ora in this contribution, when more
comprehensive, informed and expert contributions have been contributed by concerned groups and individuals.
Therefore, the most compelling case against LAN (not discussed elsewhere) arises when LAN is considered as
a public health issue.
3. Light At Night, LAN (a.k.a. Light Pollution) and Human Health
Humans are highly sensitive to LAN, which has the power to dramatically, negatively, aect circadian rhythms.
Circadian rhythms control aspects of physiology, behavior, metabolism, hormone (e.g. melatonin) secretion,
body temperature and blood pressure. Every major disease is associated to some extent with short sleep/long
light. Sleep disorders are now arguably the most prevalent health concern in the industrialized world. A multitude
of studies have made a case for a link between light at night and cancer, especially hormone inuenced cancers
such as breast and prostate. It is the shorter wavelengths of light (i.e. blue) that most aect melatonin
production in mammals. In consequence, LEDs with their preponderance of blue emission are of most concern.
In seeking to refute the link between LAN and its detrimental eects on human health MD23 are mistaken.
They (rightfully) accuse:
The claim that a digital billboard will cause cancer and other disease is an irresponsible claim.
| MD23
Agreed, to make such a claim certainly would be irresponsible. However,no such claim has ever been made.
No study has concluded that digital signs cause disease and other maladies. MD23 have mistakenly conated
the presented facts to arrive at their own conjecture. In terms of the threat to public health, dark-sky advocates
have consistently reiterated three, unassailable, truths:
(i)Billboards (and particularly the blue-rich LEDs contained in digital/electronic devices) contribute dispro-
portionately to LAN via multiple mechanisms (scattered light, lateral illumination, large surface area, high
elevation).
(ii)LAN is increasing at an accelerating rate, particularly so in metropolitan areas of the industrialized world.
(iii)LAN is linked to a number of ailments, including cancer and particularly hormonally-induced cancers.
It is unclear whether the MD23 conation and accusation manifest an eort to construct a straw man argument
by an intentional misreading, or a forgivable error overlooking 30-plus years of research linking LAN and multiple
human ailments | most securely, hormonal cancers such as breast and prostate (as well as a general decline in
immune system functioning). Here, MD23 exhibit a second instance of failing to introduce any scientic study
to refute the links between LAN (especially blue-rich light produced by LEDs) and human health. Instead, they
elect to contest a single study (of many) presented in previous correspondence (Lynam 2023), stating:
The only study that was cited to for these purposes was the article entitled Articial Light at Night
and Cancer: Global Study article by Al-Naggar, A., Anil, S. | MD23
The above statement is veritably untrue (see below). Returning to the truth, MD23 add (quite rightly):
that a single article is not substantial evidence. | MD23
Yet, despite this, MD23 proceed critique only this single article, thereby hoisting themselves by their own petard.
The truth is a previous written contribution (Lynam 2023) provided multiple citations, of which Al Nagger &
Anil (2016) merely oers a concise, unambiguous conclusion, echoed in more recent studies:
[A]LAN is signicantly correlated for all forms of cancer including lung, breast, colorectal and
prostate cancer. Immediate measures should be taken to reduce articial light at night in the main
cities around the world. | Al Nagger & Anil (2016)
For brevity, the same written contribution (as testament to the maturity of the more-than-three-decades-old
body of work establishing the link between LAN and human hormonal cancers)also cited, in plain English:
Bogard (2013)and scholarly references therein
Since these citations have been ignored, resulting in MD23’s false assertions, one is compelled to provide a
summary (see appendix).
MD23 (again, quite rightly) proclaim:
It is a fallacy of logic to indulge in the idea that correlation even implies causation. | MD23
This exposes ignorance of the cited literature, which provides at least two clear (and several more convoluted)
causality pathways between LAN and cancer (e.g. Figure 15.1 of Haim, A., Portnov, B. A., 2013):
•Via circadian disruptions to secretion of melatonin by the pineal gland.
•Via increased levels of stress hormones and energy expenditure. As additional energy is allocated to
maintain homeostasis, it may weaken the response of the immune system thus, increasing vulnerability to
pathogens and carcinogens.
As a result of these readily exposed mistakes, conations, untruths and ignorant statements, few of the assertions
contained in the MD23 discussion of LAN and Public Health can be considered reliable science-based analysis.
4. Light At Night, LAN (a.k.a. Light Pollution) and the City of Gilroy General Plan 2040
The letter of appeal asserts:
the light contribution from the proposed display would not cumulate with other sources | MD23
Somewhat frustratingly, this is a re-emergent re-framing of a previous false statement, claiming electronic
billboards:
will NOT contribute to light pollution as opponents claim. | Conrotto (2023)
Scientically, these repeated claims are simply preposterous. The laws of physics | and particularly the phe-
nomenon of Rayleigh scattering | dictate (as previously stated in a written contribution to the Planning
Commission):
Any light source which interacts with the atmosphere contributes an additive eect to the phe-
nomenon of light pollution.
| Lynam (2023)
Less intuitive (but similarly ignorant of physics) is the assertion that:
The billboard [...] would reduce light pollution and glare by angling each of the individual LEDs
downwards [...] in contrast to a traditionally illuminated display. | MD23
A brightness reduction of 10 (a multiplicative factor) is claimed. This claim may be true if only the limited
wavelengths of traditional illuminations are considered. However, the claim ignores physics (also explained in
Lynam 2023):LEDs introduce a preponderance of blue light, absent from traditional illumination. Further-
more, Rayleigh scattering (the dominant physical process contributing to sky glow) exhibits not a multiplicative
contribution, but a power law wavelength dependence (of order 4). LED illuminations emit light across more
wavelengths and bluer wavelengths. They are far more scattered than traditional illumination.
While the above (Conrotto; MD23) claims are demonstrably unphysical (and, for the third time, fail to meet
the requirements of a ‘science-based analysis’) the following claim simply strains credulity:
nothing about the Proposed Ordinance frustrates or is incompatible with the goals and policies of
the General Plan | MD23
Even if one suspends disbelief in an eort to entertain the claim, it can surely only be compatible with the
letter, and not the intent, of the General Plan. The City of Gilroy’s own guiding principles (e.g. Public Safety)
and multiple elements outlined in the City of Gilroy 2040 General Plan3 (e.g. LU 8.13; NCR 1.10) explicitly
advocate measures to limit light pollution from outdoor sources.
5. Light At Night, LAN (a.k.a. Light Pollution): Regional Proliferation
The appellants seek to assure and re-assure us that the City of Gilroy would have the unassailable police power
to enact and enforce its limitation on the number of billboards. However, it is noteworthy that almost every
reiteration of these assurances is carefully qualied by including language indicating that this power is applicable
only within the City.
The acceleration of LAN resulting from the proliferation of outdoor sources (including digital billboards) tres-
passes beyond the jurisdiction of individual cities. LAN is a regional scourge.
Regardless of whether the present appeal succeeds or fails in Gilroy, it does not guarantee that commercial
interests will not continue the trend of proposing similar ordinance modications in neighboring settlements |
ultimately resulting in an unbroken sequence of electronic billboards, punctuating every two miles (or less) along
the Highway 101 corridor from south of Salinas to north of San Francisco.To deny the present appeal is
arguably the City of Gilroy’s best opportunity to heed the intentions and warnings of the City’s own
guiding principles, Public Health professionals, dark-sky advocates and others to mitigate, curb, limit,
reduce or reverse this regional trend.
Disturbingly, in seeking to reassure us, the appellants list Californian cities that have adopted billboard ordinances
similar (but not wholly) to the one they prescribe for Gilroy (El Monte, Bell Gardens, Buena Park, Hawthorne,
Pico Revera).All of the cities that the appellants cite as a models for Gilroy to emulate are located within (and
contribute to)one of the most light-polluted regions on earth, the Los Angeles basin.
For the majority of these cities, if the relevant municipal codes and ordinances applying to signs are inspected,
one nds common language, often referring to being ‘in accordance with [sections of] the California Business and
Professions Code, CBPC’. It would be a mistake to assume that the CBPC is a homogeneous, one-size-ts-all,
set of provisions. It contains numerous clauses and exemptions, predominantly in-and-around Los Angeles. In
many contexts, the CBPC establishes regulations4 demand that:
the advertising display is authorized by, or in accordance with, an ordinance [...] adopted by the
City that regulates advertising displays by identifying the specic displays or establishing regulations
that include, at a minimum, all of the following:
(A) Number of signs and total signage area allowed.
(B) Maximum individual signage area.
(C) Minimum sign separation.
(D) Illumination restrictions and regulations, including signage refresh rate, scrolling, and brightness.
(E) Illuminated sign hours of operation.
These provisions align both with the guidelines to minimize damage to dark skies, developed by the IDA2 and
the pleas of public health researchers to reduce, curb, mitigate or reverse the proliferation of LAN. However,
the appellants prescription for Gilroy conspicuously (and in the writer’s experience,extraordinarily) excludes
4 For example, CBPC Divsion 3. Professions and vocations generally [5000 - 9998.11]; Chapter 2. Advertisers [5200 - 5486]; Article
3. Application of Chapter [5270 - 5275].
measures such as regulating illuminated sign hours of operation.
Furthermore, the ordinances in these cities (e.g.El Monte;Hawthorne) recognize:
billboards can have signicant inuence on the City’s visual character, and can, without appropriate
control, create or contribute to visual blight5 .
Not uncommonly, these ordinances contain incentives motivating (in the case of El Monte):
an existing billboard or digital billboard in existence [...] be relocated and rebuilt only within [a]
Billboard Zone5 .
Bell Gardens requires a ‘tear-down’ ratio:
remove two existing legal nonconforming billboards in order to construct one new billboard6
In the City of San Jose, during the (15 February 2022) meeting of the City Council, then Mayor Liccardo
observed:
The public hates billboards. If we took a poll on the Council, I think it would be 11:0. We would be
happy to have the City without any billboards. There is overwhelming public opposition [...] We’d
love to tear-down all of those billboards tomorrow.
In addition to adopting the IDA guidelines, the City of San Jose invoked public outcry as a vehicle to expand
the proposed conventional versus electronic billboard tear-down ratio from 4:1 to 6:1.
6. ‘Out-of-town’
Finally, proponents demean themselves by resorting to allusions to ‘out-of-town’ and non-resident opponents.
Such non-arguments have been multiply deployed | subtly and not-so-subtly | in their so-called ‘spirited’
debate7 Any entity expressing such views disgraces itself. That a multi-national organization should align itself
with such parochial views is oxymoronic. The assumption is that the appellants seek to diminish experience and
discount informed and expert opinion, freely given, volunteered in good faith and backed by genuine concern.
In our most beloved and enduring tales, fairy Godmothers and Godfathers invariably arrive from ‘out-of-town’.
Which law prevents any person from harboring anities, aections and aspirations for Gilroy? What criteria
and thresholds are to be met in order to be considered ‘residents of Gilroy or the surrounding area’? Who
holds the right to set such criteria? How far away does someone have to relocate from their birthplace to be
considered out-of-town | San Martin or Singapore? By dint of some unwritten edict, are those from ‘out-of-
town’ now barred from any community engagement? By extrapolation, proponents thus preclude those from
‘out-of-town’ from making charitable donations to Gilroy’s deserving causes. Are those not resident of Gilroy
or the surrounding area required to erase from their memories the people of Gilroy with whom they have had
enjoyable interactions? By whose decree must those not resident of Gilroy or the surrounding area, who ed
the August 2020 SCU complex wildre as it set their homes aame, now un-feel and abandon their fondness
for the City of Gilroy and the tenderness shown to them by its people, who oered succor and refuge?
5 City of El Monte Zoning Code, Division 8 - Signage & Billboard Regulations; City of Hawthorne Municipal Code, Title 17, Zoning.
6 City of Bell Gardens Municipal Code, Zoning and Planning Regulations, 9.40.050 Billboard standards.
7 ‘Many of the opponents of the sign are not residents of Gilroy or the surrounding area’ (Conrotto 2022); ‘I noticed that a lot of
them are out-of-town’ (Conrotto, Public comment to Planning Commission, 19 January 2023); ‘...these people from out-of-town...
(Conrotto, Public comment to Planning Commission, 2 February 2023)’; ‘...out-of-town members of a group...’ (MD23).
7. Conclusion
It’s happening: Estimates suggest that Light At Night, LAN (a.k.a. light pollution) is accelerating at a
rate that out-paces that of population growth (Gaston & Sanchez de Miguel 2022).It’s LEDs: LEDs, their
preponderance of blue light and the outdoor devices that use them contribute disproportionately to LAN.We’re
sure: Decades of objective, peer-reviewed scientic (astronomical and public health) studies agree.It’s bad
(and getting worse): In 1989, of 17 major (exclusively US-based) observatories, Lick was ranked among the
top 3 most heavily light-polluted astronomical sites (Garstang 1989b) at visible wavelengths. In 2022, in a list
of 23 major observatories worldwide, Lick was cited as the most aected astronomical site (Green et al. 2022)
in the visible regime. LAN, via circadian disruption, is linked with a profusion of human ailments, not limited
to behavioral changes, sleep disorders (arguably the most prevalent health concern in the industrialized world),
diabetes, depression, obesity, heart disease, Mild Cognitive Impairment, MCI and cancers of the lung, colon,
rectum. LAN has multiple causal connections to breast and prostate cancer.We can x it : Take measures to
reduce the surging light pollution at night. Regulate nighttime advertising. Switching o such illumination can
contribute to the most important aims of decreasing light pollution. Curb the wide scale introduction of short
wavelength (blue-rich) illumination.
The commercially-motivated appellants seek to overturn the long-standing will of the people of Gilroy (enshrined
in the City’s guiding principles) in an eort to acquire a digital billboard monopoly. Doing so shall exacerbate
the accelerating scourge of regional light pollution. The appellants oer no contest to the fact LEDs (and
the devices that employ them) pollute across the broad visual spectrum and emit a preponderance of short
wavelength/blue light. Electing to free themselves of the encumbrance of scientic rigor, the appellants have
ignored the laws of physics (specically the phenomenon of scattering), repeatedly made some claims that are
unphysical and others that strain credulity. Responding to peer-reviewed scientic evidence, quantifying the
growing impact of LAN on astronomy in general | and Lick Observatory in particular | absent any supporting
source | the appellants level the vacuous charge of ‘misuse’. Again, in the absence of objective studies to
support their case, the appellants proer unfounded conjecture. They have been consistently and extraordinarily
insensitive to appeals to mitigate LAN by adopting IDA guidance (backed by decades of astronomical and public
health research, as well as the City’s guiding principles). Mistakenly, they have conated facts and untruthfully
denied the existence of a multitude of citations. They arrive at narrowly-drawn conclusions, based on sparsely-
selected (and in one case, single) articles. They have propounded false assertions and downplayed (willfully or
accidentally) the links between LAN and human health and the causal connections established between LAN
and some cancers. Not once, not twice, but thrice, the content of the appeal has failed to meet the standard
required of objective science-based analysis. The appellants prescribe for Gilroy an ordinance that seeks to
emulate one of the most light-polluted regions on earth. Assurances are carefully qualied by within the city,
thus disregarding the regional trespass of LAN. Measures to regulate, for example, illuminated sign hours of
operation, are omitted | as is the suggestion of revocations and/or tear-downs. At no stage has the adoption
of IDA guidance been entertained.
Therefore, the City Council is implored to respect the considered judgment of their expert panel of advisers,
the Planning Commission. Please seize this opportunity to abide by the intentions of the City’s own guiding
principles. Deny the ordinance change.
Yours faithfully,
Dr Paul D. Lynam FRAS
Astronomer
UCO/Lick Observatory
Appendix: Light At Night, LAN (a.k.a. Light Pollution) and Human Health
Beginning with Bogard (2013):
An increasing number of studies [...] have made a compelling case for a link between light at night
and cancer, especially hormone influenced cancers such as breast and prostate (Bogard 2013, p.104).
The World Health Organization’s International Agency for Research on Cancer, IARC [the specialized
cancer agency of the WHO] listed [...] circadian disruption as ‘a probable human carcinogen’ (Bogard
2013, p.293, citing Stevens et al. 2011).
IARC (2020) restated that night shift work and circadian disruption was ‘probably carcinogenic to humans’— on
this occasion specifying cancers of the breast, prostate, colon and rectum.
In 2009, the American Medical Association, AMA voiced its unanimous support for ‘light pollution
control eorts [...] for both public safety and energy safety’ (Bogard 2013, p.293).
An excellent summary of the connections between light at night and health can be found in Chepsiuk
(2009). (Bogard 2013, p.294).
For a highly readable article detailing the potential connections between light at night and cancer, see
Richard G. Stevens Light-at-Night, Circadian Disruptions and Breast Cancer: Assessment of Existing
Evidence’ (Bogard 2013, p. 294).
Beginning with the emergence of patterns between geographic distribution, electrical power use and breast cancer
in the 1970s and 1980s, studies linking LAN to breast cancer have the longest heritage. They are so numerous
that while Bogard (2013) discusses them in general, they cannot all be explicitly cited. The first study providing
explicit evidence that LAN may be associated with the risk of developing breast cancer appeared is arguably
Davis et al. (2001).
Similarly, among the earliest studies linking LAN and prostate (colon and lung) cancer are Kubo et al. (2006)
and Kloog et al. (2009).
The first book (Haim & Portnov 2013) to address the linkage between light pollution and Breast and Colon
cancer in humans was published in the same year as Bogard. It summarized the general knowledge and scientific
evidence accumulated in the preceding decades. The preface states:
In many electrical light bulbs used today and considered environmentally friendly electrical energy
is converted into short wavelength [i.e. blue-rich] illumination thus increasing the light intensity
to the levels we have not been used to in the past. Such illumination eectively becomes light
pollution which disrupts pineal melatonin production. Among its other properties, melatonin is
an antioncogenic agent, and therefore, its suppression increases the risks of developing breast and
prostate cancers.
Among Haim & Portnov’s (2013) conclusions:
If we put together chronobiological evidence about negative eects of short wavelength illumination
and suppressing of melatonin production at night,we may regret [introducing energy-saving light
sources, such as LED and florescent light tubes] due to health hazards as well as economic
and social costs associated with it, and, therefore, it should be considered unsustainable.
Local authorities may contribute to the reduction of light pollution by implementing more
sustainable nighttime illumination policies, such as, lowering illumination intensities in public
places to minimally acceptable levels, by surveying actual needs and caring to provide minimal light
levels required by certain activities (e.g., walking, driving, etc.) without over-illumination.
Regulations on nighttime advertising (which is virtually non-existent today) should also
be implemented and switching o such illumination can contribute to the most important
aims of decreasing light pollution and energy-saving. Unfortunately, we are used to the
fact that huge areas are lit at night without any actual need. This attitude should change.
Public policy makers should also be convinced to curb the wide scale introduction of short wave
length illumination, which is potentially the most dangerous component of light pollution.
Researchers have linked working at night [circadian disruption] with ailments such as diabetes [e.g.
Zheng et al. (2023) and references therein], obesity and heart problems [e.g. Münzel et al. (2020)
and references therein)] (Brogard 2013, p.93).
Beyond Bogard, augmenting studies of physical health, a pilot study by Bell et al. (2014) indicates interactions
with ‘Dark Nature’ promotes multiple aspects of well-being and enrichment.
More recent work (Chen et al. 20221 ) concludes:
Increased exposure to LAN is associated with higher risk of prevalent Mild Cognitive Impairment,
MCI (a transitional stage between normal aging and dementia).
Their recommendation eerily echos that of Al Nagger & Anil (2016):
Policy-makers should take eective measures to curb the surging light pollution at night ,
considering the heavy burden of diseases related to excessive LAN exposure.
1 Highlighted in 2 February 2023 spoken contribution to the Planning Commission
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