2023-01-19 - Public Correspondence - Item 7.2 1
Resources and References that helped inform
Sierra Club’s Light Pollution Policy Update
(Last updated 3/7/2021)
Over 70 resources and references (including websites, articles, publications, and reports) were reviewed during Sierra
Club’s March 2021 update to its light pollution national policy. The list is only provided to document resources used
during policy development. Inclusion of any given resource in this list should not be construed as an endorsement by
Sierra Club. The main resources consulted are listed below, organized by a relevant category. Several resources cover
multiple issues, but each is only listed once.
Sierra Club Advocacy
Sierra Club AddUp Petition to City Mayors: Protect the Night Against Light Pollution (started in Feb 2018)
https://addup.sierraclub.org/campaigns/protect-the-night
Sierra Club Articles
On the Hunt for Stars: In Search of a Truly Dark Night Sky. Heather Smith, Feb 27, 2018. SIERRA magazine, March/April
2018 edition. https://www.sierraclub.org/sierra/2018-2-march-april/feature/hunt-for-stars-dark-skies-preserves-and-parks
Reclaiming the Night. SIERRA magazine. Katie O'Reilly. https://www.sierraclub.org/sierra/slideshow/reclaiming-night
General Educational Resources
National Park Service Night Skies, www.nps.gov/subjects/nightskies
Light pollution - a global discussion. Schulte-Römer, N., Dannemann, E., Meier, J. (2018): Helmholtz Centre for Environmental
Research - UFZ, Leipzig, 248 pp.
http://www.lightpollutiondiscussion.net
The Right to Dark Skies, 2016, United Nations Educational, Scientific and Cultural Organization (UNESCO Mexico)
https://unesdoc.unesco.org/ark:/48223/pf0000246131
Our nights are getting brighter, and Earth is paying the price , by Nadia Drake, National Geographic, published April 3, 2019
https://www.nationalgeographic.com/science/2019/04/nights-are-getting-brighter-earth-paying-the-price-light-pollution-dark-
skies/
Treat artificial light like other forms of pollution, say scientists. Jonathan Watts, The Guardian. Nov 2, 2020.
https://www.theguardian.com/environment/2020/nov/02/treat-artificial-light-form-pollution-environment
Excerpt: “What stands out is how pervasive the effects are. The effects were found everywhere – microbes, invertebrates,
animals and plants,” said the lead author, Kevin Gaston, a professor at the university’s Environment and Sustainability Insti tute.
“We need to start thinking about lighting in the way we think of other big systemic pressures like climate change.”
Light pollution – extent, effects and approaches. TAB-Fokus no. 25, Jun 2020, Office of Technology Assessment at the German
Bundestag. Christoph Schröter-Schlaack, et al.
http://www.tab-beim-bundestag.de/en/news/20200828.html
Summary: In addition to the intended effects, the increasing use of artificial outdoor lighting also entails a number of unde sirable
side effects referred to as light pollution. Artificial lighting can disturb the circadian rhythms of humans and animals, whi ch are
controlled by the change of day and night, and is suspected of being involved in the development of various diseases. Moreo ver,
the increasing illumination of the night influences the natural behaviour of animals. Besides habitat changes, the consequenc es are
ranging from changes in hunting or reproductive behaviour to the deadly attraction effect of light sources, e. g. for i nsects.
However, the longterm consequences of these changes for entire populations, communities or landscapes are still poorly
understood. Options for reducing light pollution exist both technologically and in terms of regulation and approval of lighti ng
installations.
Light Pollution Is Taking Away Our Night Skies. Here’s Why That Matters. 11/13/2019. HuffPost. By Kyla Mandel
https://www.huffpost.com/entry/city-light-pollution-night-sky-star-protection_n_5dc9d1fee4b00927b2381233
Some cities and states are trying to protect our night sky “for the health and wellbeing for all living things.”
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Light Pollution Trends
Artificially lit surface of Earth at night increasing in radiance and extent, by Christopher C. M. Kyba, Theres Kuester,
Alejandro Sánchez de Miguel, Kimberly Baugh, Andreas Jechow, Franz Hölker, Jonathan Bennie, Christopher D. Elvidge,
Kevin J. Gaston, and Luis Guanter. Science Advances 22 Nov 2017: Vol. 3, no. 11, e1701528, DOI: 10.1126/sciadv.1701528
http://advances.sciencemag.org/content/3/11/e1701528
Abstract: A central aim of the “lighting revolution” (the transition to solid-state lighting technology) is decreased energy
consumption. This could be undermined by a rebound effect of increased use in response to lowered cost of light. We use the
first-ever calibrated satellite radiometer designed for night lights to show that from 2012 to 2016, Earth’s artificially lit outdoor
area grew by 2.2% per year, with a total radiance growth of 1.8% per year. Continuously lit areas brightened at a rate of 2.2 % per
year. Large differences in national growth rates were observed, with lighting remaining stable or decreasing in only a few
countries. These data are not consistent with global scale energy reductions but rather indicate increased light pollution, w ith
corresponding negative consequences for flora, fauna, and human well-being.
The new world atlas of artificial night sky brightness. Falchi, F., Cinzano, P., Duriscoe, D., Kyba, C.C.M., Elvidge, C.D.,
Baugh, K., Portnow, B.A., Rybnikova, N.A., & Furgoni, R. (2016). Science Advances, 2:e1600377.
https://advances.sciencemag.org/content/2/6/e1600377
Abstract: Artificial lights raise night sky luminance, creating the most visible effect of light pollution—artificial skyglow. Despite
the increasing interest among scientists in fields such as ecology, astronomy, health care, and land -use planning, light pollution
lacks a current quantification of its magnitude on a global scale. To overcome this, we present the world atlas of artificial sky
luminance, computed with our light pollution propagation software using new high -resolution satellite data and new precision sky
brightness measurements. This atlas shows that more than 80% of the world and more than 99% of the U.S. and European
populations live under light-polluted skies. The Milky Way is hidden from more than one-third of humanity, including 60% of
Europeans and nearly 80% of North Americans. Moreover, 23% of the world’s land surfaces between 75°N and 60°S, 88% of
Europe, and almost half of the United States experience light-polluted nights.
Light pollution in USA and Europe: The good, the bad and the ugly. F. Falchi, R. Furgoni, T.A. Gallaway, N.A. Rybnikova,
B.A. Portnov, K. Baugh, P. Cinzano, C.D. Elvidge, Elsevier Journal of Environmental Ma nagement, Volume 248, 2019,
109227, 15 October 2019
http://www.sciencedirect.com/science/article/pii/S0301479719309296
Abstract: Light pollution is a worldwide problem that has a range of adverse effects on human health and natural ecosystems.
Using data from the New World Atlas of Artificial Night Sky Brightness, VIIRS -recorded radiance and Gross Domestic Product
(GDP) data, we compared light pollution levels, and the light flux to the population size and GDP at the State and County levels
in the USA and at Regional (NUTS2) and Province (NUTS3) levels in Europe. We found 6800 -fold differences between the most
and least polluted regions in Europe, 120 -fold differences in their light flux per capita, and 267-fold differences in flux per GDP
unit. Yet, we found even greater differences between US counties: 200,000 -fold differences in sky pollution, 16,000-fold
differences in light flux per capita, and 40,000-fold differences in light flux per GDP unit. These findings may inform policy-
makers, helping to reduce energy waste and adverse environmental, cultural and health consequences associated with light
pollution.
Global Trends in Exposure to Light Pollution in Natural Terrestrial Ecosystems. Bennie, J.; Duffy, J.P.; Davies, T.W.; Correa-
Cano, M.E.; Gaston, K.J. Remote Sens. 2015, 7, 2715-2730.
https://www.mdpi.com/2072-4292/7/3/2715
Abstract: The rapid growth in electric light usage across the globe has led to increasing presence of artificial light in natural and
semi-natural ecosystems at night. This occurs both due to direct illumination and skyglow - scattered light in the atmosphere.
There is increasing concern about the effects of artificial light on biological processes, biodiversity and the functioning of
ecosystems. We combine intercalibrated Defense Meteorological Satellite Program’s Operational Linescan System (DMSP/OLS)
images of stable night-time lights for the period 1992 to 2012 with a remotely sensed landcover product (GLC2000) to assess
recent changes in exposure to artificial light at night in 43 global ecosystem types. We find that Mediterranean -climate
ecosystems have experienced the greatest increases in exposure, followed by temperate ecosystems. Boreal, Arctic and montane
systems experienced the lowest increases. In tropical and subtropical regions, the greatest increases are in mangroves and
subtropical needleleaf and mixed forests, and in arid regions increases are mainly in forest and agricultural areas. The global
ecosystems experiencing the greatest increase in exposure to artificial light are already localized and fragmented, and often of
particular conservation importance due to high levels of diversity, endemism and rarity. Night time remote sensing can play a key
role in identifying the extent to which natural ecosystems are exposed to light pollution.
Direct measurement of the contribution of street lighting to satellite observations of nighttime light emissions from urban
areas. Kyba, C, et al. Lighting Research & Technology. October 2020.
https://doi.org/10.1177/1477153520958463
Abstract: Nighttime light emissions are increasing in most countries worldwide, but which types of lighting are responsible for
the increase remains unknown. Also unknown is what fraction of outdoor light emissions and associated energy use are due to
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public light sources (i.e. streetlights) or various types of private light sources (e.g. advertising). Here we show that it is possible to
measure the contribution of street lighting to nighttime satellite imagery using ‘smart city’ lighting infrastructure. The ci ty of
Tucson, USA, intentionally altered its streetlight output over 10 days, and we examined the change in emissions observed by
satellite. We find that streetlights operated by the city are responsible for only 13% of the total radiance (in the 500 –900 nm band)
observed from Tucson from space after midnight (95% confidence interval 10–16%). If Tucson did not dim their streetlights after
midnight, the contribution would be 18% (95% confidence interval 15–23%). When streetlights operated by other actors are
included, the best estimates rise to 16% and 21%, respectively. Existing energy and lighting policy related to the sustainability of
outdoor light use has mainly focused on street lighting. These results suggest an urgent need for consideration of other type s of
light sources in outdoor lighting policy.
Anthropogenic Light Disrupts Natural Light Cycles in Critical Conservation Areas, Seymoure, B, et al. (August 19, 2019).
https://ssrn.com/abstract=3439670
Abstract: Anthropogenic lighting drastically alters nocturnal environments, threatening a wide range of species by disrupting light
regimes that regulate fundamental biological processes such as reproduction, foraging, and predator defense. We translate sat ellite
measures of anthropogenic light radiating from the earth to a biologically relevant measurement – the amount of light scattered
back to the earth (horizontal illuminance). Anthropogenic light exceeding the natural level produced by stars, galactic light , and
airglow on a clear moonless night (i.e., new moon conditions) affects 22.9% of the Earth’s terrestrial surface, as well as 51.0% of
Key Biodiversity Area units, 77.1% of Global Protected Area units, and approximately 20% of the most biodiverse areas for
mammals, birds, and amphibians. Thus, due to anthropogenic sources, these environments experience at least double the levels of
natural illuminance during half of the night hours in a year. To facilitate biological interpretation of these levels of anth ropogenic
illuminance observed globally, we undertook a systematic literature review of animal responses to changing nocturnal light levels.
Known biological effects from the current anthropogenic illuminance levels range from behavioral and physiological alteration s
to increased mortality, which have been documented in 117 species from 23 orders and 8 classes. These findings provide a
biological perspective on global light pollution, and they identify regions where reductions in anthropogenic illuminance wou ld
yield the greatest benefits for conserving biodiversity.
Effects of the COVID-19 Lockdown on Urban Light Emissions: Ground and Satellite Comparison. Bustamante-Calabria, M,
Sánchez de Miguel, A, et al. Remote Sensing. Jan 2021, Vol 13, Issue 2, 258.
https://www.mdpi.com/2072-4292/13/2/258
Abstract Excerpt: ‘Lockdown’ periods in response to COVID-19 have provided a unique opportunity to study the impacts of
economic activity on environmental pollution (e.g., NO2, aerosols, noise, light)... Here, to analyze the effect of lockdown on
urban light emissions, we use ground and satellite data for Granada, Spain, during the COVID-19 induced confinement of the
city’s population from 14 March until 31 May 2020. We find a clear decrease in light pollution due both to a decrease in ligh t
emissions from the city and to a decrease in anthropogenic aerosol conten t in the atmosphere which resulted in less light being
scattered. A clear correlation between the abundance of PM10 particles and sky brightness is observed, such that the more
polluted the atmosphere the brighter the urban night sky.
Environmental and Social Justice
Light pollution inequities in the continental United States: A distributive environmental justice analysis. Nadybal S.M., Collins
T.W., Grineski S.E.. Environmental Research, Vol 189, 2020, 109959.
http://www.sciencedirect.com/science/article/pii/S0013935120308549
Abstract: Excessive exposure to ambient light at night is a well-documented hazard to human health, yet analysts have not
examined it from an environmental justice (EJ) perspective. We conducted the first EJ study of exposure to light pollution by
testing for socially disparate patterns across the continental United States (US)... We found evidence of disparities in exposures to
light pollution based on racial/ethnic minority and low-to-mid socioeconomic statuses. Americans of Asian, Hispanic or Black
race/ethnicity had population-weighted mean exposures to light pollution in their neighborhoods that were app roximately two
times that of White Americans... neighborhoods composed of higher proportions of Blacks, Hispanics, Asians, or renter -
occupants experienced greater exposures to ambient light at night. Stratified analyses indicated that those patterns of ine quity did
not substantially vary based on urban-rural context. Findings have implications for understanding environmental influences on
health disparities, raise concerns about the potential for a multiple environmental jeopardy situation, and highlight th e need for
policy actions to address light pollution.
An incandescent truth: Disparities in energy-efficient lighting availability and prices in an urban U.S. county. Reames, Tony
G., Michael A. Reiner, and M. Ben Stacey. (2018) Applied Energy 218:95 -103.
https://www.sciencedirect.com/science/article/abs/pii/S0306261918302769
Abstract Excerpt: In the U.S. lighting represents about 9% of the average household's primary e nergy consumption and 20% of
the average household's energy bill. Lighting in U.S. homes is in a state of transition with steady growth in the adoption of more
energy-efficient lighting technology, such as, compact florescent lamps (CFL) and light-emitting diodes (LEDs). However, the
adoption of energy-efficient lighting is not equitably distributed across socioeconomic groups, with poorer households less likely
to adopt than higher-income households... We found that (1) energy-efficient bulbs were less available in high-poverty areas and
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smaller stores; (2) energy-efficient bulbs were more expensive in high-poverty areas and smaller stores; (3) upgrade costs from
incandescent and halogen lamps (IHLs) to CFLs or LEDs were higher in high poverty areas; and (4 ) both poverty and store type
were significant predictors of LED availability, while store type was the most significant predictor of LED price variability . We
suggest several ways that the development and implementation of energy efficiency policies and p rograms may consider these
disparities that affect access and affordability, in order to achieve a more just energy-efficient transition.
Up in smoke: Characterizing the population exposed to flaring from unconventional oil and gas development in the
contiguous US. Cushing Lara J, et al. Feb 2021. Environmental Research Letters. Vol. 16, No 3.
https://iopscience.iop.org/article/10.1088/1748 -9326/abd3d4
Abstract Excerpt: The disposal of waste gas via intentional combustion (flaring) from unconventional oil and gas (UOG)
development has also been on the rise, and may expose nearby residents to toxic air pollutants, light pollution and noise... We
found that three basins accounted for over 83% of all UOG flaring activity in the contiguous US over the 8 year study period. We
estimated that over half a million people in these basins reside within 5 km of a flare, and 39% of them lived near more than 100
nightly flares. Black, indigenous, and people of color were disproportionately exposed to flaring.
Light Pollution in San Antonio, TX: An Environmental Justice Issue. Alvarez, V, et al. May 2020. Environmental Studies
Student Works. Trinity University.
https://digitalcommons.trinity.edu/env_studocs/2
Abstract Excerpt: the environmental justice movement often overlooks the issue of light pollution, even though light pollution is
higher in urban low-income areas. There is a lack of studies examining how light pollution varies between communities on a
regional, state, or municipal scale... The mid-income neighborhoods had the greatest median and maximum light pollution levels,
while high-income neighborhoods had the lowest median illuminance. These results indicate that mid -income neighborhoods are
subject to the greatest amount of light pollution by area and intensity.
Ecological, Wildlife and Human Impacts
Ecological light pollution. Longcore, T. and Rich, C. (2004), Frontiers in Ecology and the Environment, 2: 191 -198.
https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1890/1540-9295%282004%29002%5B0191%3AELP%5D2.0.CO%3B2
Abstract: Ecologists have long studied the critical role of natural light in regulating species interactions, but, with limit ed
exceptions, have not investigated the consequences of artificial night lighting. In the past century, the extent and intensity of
artificial night lighting has increased such that it has substantial effects on the biology and ecology of species in the wil d. We
distinguish “astronomical light pollution”, which obscures the view of the night sky, from “ecological light pollution”, which
alters natural light regimes in terrestrial and aquatic ecosystems. Some of the catastrophic consequences of light for certai n
taxonomic groups are well known, such as the deaths of migratory birds around tall lighted structures, and those of hatchling sea
turtles disoriented by lights on their natal beaches. The more subtle influences of artificial night lighting on the behavior and
community ecology of species are less well recognized, and constitute a new focus for research in ecology and a pressing
conservation challenge.
Ecological consequences of artificial night lighting. Rich, C. and T. Longcore. (eds.). 2006. Island Press, Washington, D.C.
https://www.urbanwildlands.org/ecanlbook.html
The first book to consider the environmental effects of the intentional illumination of the night. It brings together leading
scientists from around the world to review the state of knowledge on the subject and to describe specific effects that have been
observed across a full range of taxonomic groups, including mammals, birds, reptiles and amphibians, fishes, invertebrates, a nd
plants… provides a scientific basis to begin addressing the challenge of conserving the nighttime environment. It cogently
demonstrates the vital importance of this until -now neglected topic and is an essential new work for conservation planners,
researchers, and anyone concerned with human impacts on the natural world.
Light Pollution Is a Driver of Insect Declines, by Owens, A, et al. (April 26, 2019)
https://ssrn.com/abstract=3378835
Abstract: Insects around the world are rapidly declining. Concerns over what this loss means for food security and ecological
communities have compelled a growing number of researchers to search for the key drivers behind the decline. Habitat loss,
pesticide use, invasive species, and climate change all have likely played a role, but we pos it here that artificial light at night
(ALAN) is another important — but often overlooked — bringer of the insect apocalypse. We first discuss the history and extent
of ALAN, and then present evidence that ALAN has led to insect declines through its interf erence with the development,
movement, foraging, and reproductive success of diverse insect species, as well as its positive effect on insectivore predati on. We
conclude with a discussion of how artificial lights can be tuned to reduce their impacts on vul nerable populations. ALAN is
unique among anthropogenic habitat disturbances in that it is fairly easy to ameliorate, and leaves behind no residual effect s.
Greater recognition of the ways in which ALAN impacts insects can help conservationists reduce or e liminate one of the major
drivers of insect declines.
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A meta-analysis of biological impacts of artificial light at night. Nature Ecology & Evolution (2020), Dirk Sanders, Enric Frago,
Rachel Kehoe, Christophe Patterson & Kevin J. Gaston
https://doi.org/10.1038/s41559-020-01322-x
https://datadryad.org/stash/dataset/doi:10.5061/dryad.wpzgmsbjn
Abstract: Natural light cycles are being eroded over large areas of the globe by the direct emissions and sky brightening that
result from sources of artificial night -time light. This is predicted to affect wild organisms, particularly because of the central role
that light regimes play in determining the timing of biological activity. Although many empirical studies have reported such
effects, these have focused on particular species or local communities and have thus been unable to provide a general evaluat ion
of the overall frequency and strength of these impacts. Using a new database of published studies, we show that exposure to
artificial light at night induces strong responses for physiological measures, daily activity patterns and life history trait s. We found
particularly strong responses with regards to hormone levels, the onset of daily activity in diurnal species and life history traits,
such as the number of offspring, predation, cognition and seafinding (in turtles). So far, few studies have focused on the im pact of
artificial light at night on ecosystem functions. The breadth and often strength of biological impacts we reveal highlight the need
for outdoor artificial night-time lighting to be limited to the places and forms—such as timing, intensity and spectrum—where it
is genuinely required by the people using it to minimize ecological impacts.
Longer photoperiods through range shifts and artificial light lead to a destabilizing increase in host –parasitoid interaction
strength. Kehoe, R, Sanders, D, Cruse, D, et al. Journal of Animal Ecology. 2020; 89: 2508–2516.
https://doi.org/10.1111/1365-2656.13328
Excerpts: Many organisms are experiencing changing daily light regimes due to latitudinal range shifts driven b y climate change
and increased artificial light at night (ALAN). Activity patterns are often driven by light cycles, which will have important
consequences for species interactions... Here we demonstrate that ALAN impact interacts with daylength and temper ature by
changing the interaction strength between a common day‐active consumer species and its host in a predictable way. Our results
further suggest that range expansion or ALAN‐induced changes in light regimes experienced by insects and their natural en emies
will result in unstable dynamics beyond key tipping points in daylength... Finally, the strong response of a diurnal host –parasitoid
system reported here also emphasizes the importance of focussing on the impact of ALAN not just on nocturnal species but also
on those that are chiefly diurnal, on which the effects of ALAN may be just as profound, if not as intuitive.
Artificial nightlight alters the predator–prey dynamics of an apex carnivore. Ditmer, MA, et al. (2020). Ecography
https://doi.org/10.1111/ecog.05251
Abstract Excepts: Our results indicate that deer used the anthropogenic environments to access forage and were more active at
night than their wildland conspecifics. Despite higher nightlight levels, cougars killed deer at the wildland–urban interface, but
hunted them in the relatively darkest locations. Light had the greatest effect of all covariates on where cougars killed deer at the
wildland–urban interface. Both species exhibited functio nal responses to light pollution at fine scales; individual cougars and deer
with less light exposure increasingly avoided illuminated areas when exposed to greater radiance, whereas deer living in the
wildland–urban interface selected elevated light levels. We conclude that integrating estimates of light pollution into ecological
studies provides crucial insights into how the dynamic human footprint can alter animal behavior and ecosystem function acros s
spatial scales.
Coral Gametogenesis Collapse under Artificial Light Pollution. Ayalon et al. Current Biology. Nov 2020
https://doi.org/10.1016/j.cub.2020.10.039
Excerpts: Marine organisms, including coral reefs in particular, rely on the natural lig ht cycles of sunlight and moonlight to
regulate various physiological, biological, and behavioral processes. Here, we demonstrate that light pollution caused delayed
gametogenesis and unsynchronized gamete release in two coral species, Acropora millepora and Acropora digitifera, from the
Indo-Pacific Ocean… With the global transition toward LED lighting, which tends to have higher emissions in the blue spectrum,
more coral reefs could be affected by artificial light, as blue light penetrates deeper into th e water column. This spectral shift is
expected to be amplified by the current rapid population growth in coastal regions ... Our experimental results are corroborated
by in situ observations, which have shown disruption of gametogenesis and loss of spawni ng synchrony in corals occurring at
sites that are heavily polluted by artificial lights. These results demonstrate that artificial light must be considered in c onservation
plans for coral reefs near areas of human activity.
Sensory pollutants alter bird phenology and fitness across a continent. Senzaki, M., Barber, J.R., Phillips, J.N. et al. Nature
587, 605–609 (2020)
https://doi.org/10.1038/s41586-020-2903-7
Abstract: Expansion of anthropogenic noise and night lighting across our planet is of increasing conservation concern. Despite
growing knowledge of physiological and behavioural responses to these stimuli from single -species and local-scale studies,
whether these pollutants affect fitness is less clear, as is how and why species vary in their sensitivity to these anthropic stressors.
Here we leverage a large citizen science dataset paired with high -resolution noise and light data from across the contiguous
United States to assess how these stimuli affect reproductive success in 142 bird species. We find responses to both sensory
pollutants linked to the functional traits and habitat affiliations of species. For example, overall nest success was negativ ely
correlated with noise among birds in closed environments. Species-specific changes in reproductive timing and hatching success
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in response to noise exposure were explained by vocalization frequency, nesting location and diet. Additionally, increased li ght-
gathering ability of species’ eyes was associated with stronger advancements in reproductive timing in response to light exposure,
potentially creating phenological mismatches. Unexpectedly, better light -gathering ability was linked to reduced clutch failure
and increased overall nest success in response to light exposure, raising important questions about how responses to sensory
pollutants counteract or exacerbate responses to other aspects of global change, such as climate warming. These findings
demonstrate that anthropogenic noise and light can substantially affect breeding bird phenology and fitness, and underscore the
need to consider sensory pollutants alongside traditional dimensions of the environment that typically inform biodiversity
conservation.
Bright lights in the big cities: migratory birds’exposure to artificial light. Horton, KG., Nilsson, C., et al, 2019. Frontiers in
Ecology and the Environment, April 2019.
https://doi.org/10.1002/FEE.2029
https://www.youtube.com/watch?v=_gXSN2GmI8M
Abstract: Many species of migratory birds have evolved the ability to migrate at night, and the recent and rapid expansion of
artificial light at night has markedly altered the nighttime sky through which they travel. Migrating birds regularly pass through
heavily illuminated landscapes, and bright lights affect avian orientation. But risks to migrating birds from artificial ligh t are not
spatially or temporally uniform, representing a challenge for mitigating potential hazards and developing action plans to catalog
risks at continental scales. We leveraged over two decades of remote‐sensing data collected by weather surveillance radar and
satellite‐based sensors to identify locations and times of year when the highest numbers of migrating birds are exposed to light
pollution in the contiguous US. Our continental‐scale quantification of light exposure provides a novel opportunity for dynam ic
and targeted conservation strategies to address the hazards posed by light pollution to nocturnally migrating birds.
High-intensity urban light installation dramatically alters nocturnal bird migration. Van Doren BM, Horton KG, et al.
Proceedings of the National Academy of Sciences, Oct 2017, 114 (42) 11175-11180
https://www.pnas.org/content/114/42/11175
Abstract Excerpt: Billions of nocturnally migrating birds move through increasingly photopo lluted skies, relying on cues for
navigation and orientation that artificial light at night (ALAN) can impair… We studied effects of ALAN on migrating birds by
monitoring the beams of the National September 11 Memorial & Museum's “Tribute in Light” in New York, quantifying
behavioral responses with radar and acoustic sensors and modeling disorientation and attraction with simulatio ns… When the
installation was illuminated, birds aggregated in high densities, decreased flight speeds, followed circular flight paths, and
vocalized frequently… However, behavioral disruptions disappeared when lights were extinguished, suggesting that selective
removal of light during nights with substantial bird migration is a viable strategy for minimizing potentially fatal inte ractions
among ALAN, structmelures, and birds. Our results also highlight the value of additional studies describing behavioral patterns of
nocturnally migrating birds in powerful lights in urban areas as well as conservation implications for such lighting installations.
The ecological impacts of nighttime light pollution: a mechanistic appraisal. Gaston, K. J., Bennie, J., Davies, T. W. and
Hopkins, J., Biological Reviews, Vol 88, Issue 4, 2013, Cambridge Philosophical Society
https://onlinelibrary.wiley.com/doi/full/10.1111/brv.12036
Abstract: The ecological impacts of nighttime light pollution have been a longstanding source of concern, accentuated by rea lized
and projected growth in electrical lighting. As human communities and lighting technologies develop, artificial light increas ingly
modifies natural light regimes by encroaching on dark refuges in space, in time, and across wavelengths. A wide variety of
ecological implications of artificial light have been identified. However, the primary research to date is largely focused on the
disruptive influence of nighttime light on higher vertebrates, and while comprehensive reviews have been compiled along
taxonomic lines and within specific research domains, the subject is in need of synthesis within a common mechanistic
framework. Here we propose such a framework that focuses on the cross -factoring of the ways in which artificial lighting alters
natural light regimes (spatially, temporally, and spectrally), and the ways in which light influences biological systems, particularly
the distinction between light as a resource and light as an information source. We review the evidence for each of the
combinations of this cross-factoring. As artificial lighting alters natural patterns of light in space, time and across wavelengths,
natural patterns of resource use and information flows may be disrupted, with downstream effects to the structure and functio n of
ecosystems. This review highlights: (i) the potential influence of nighttime lighting at all levels of biological organisation (from
cell to ecosystem); (ii) the significant impact that even low levels of nighttime light pollution can have; and (iii) the exi stence of
major research gaps, particularly in terms of the impacts of light at population and ecosystem levels, identification of inte nsity
thresholds, and the spatial extent of impacts in the vicinity of artificial lights.
Light Pollution, Circadian Photoreception, and Melatonin in Vertebrates. Grubisic M, Haim A, Bhusal P, Dominoni DM,
Gabriel KMA, Jechow A, Kupprat F, Lerner A, Marchant P, Riley W, Stebelova K, van Grunsven RHA, Zeman M, Zubidat
AE, Hölker F. Sustainability. 2019; 11(22):6400.
https://www.mdpi.com/2071-1050/11/22/6400
Abstract: Artificial light at night (ALAN) is increasing exponentially worldwide, accelerated by the transition to new effici ent
lighting technologies. However, ALAN and resulting light pollution can cause unintended physiological consequences. In
vertebrates, production of melatonin—the “hormone of darkness” and a key player in circadian regulation—can be suppressed by
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ALAN. In this paper, we provide an overview of research on melatonin and ALAN in vertebrates. We discuss how ALAN
disrupts natural photic environments, its effect on melatonin and circadian rhythms, and different photoreceptor systems acro ss
vertebrate taxa. We then present the results of a systematic revie w in which we identified studies on melatonin under typical light -
polluted conditions in fishes, amphibians, reptiles, birds, and mammals, including humans. Melatonin is suppressed by extreme ly
low light intensities in many vertebrates, ranging from 0.01 –0.03 lx for fishes and rodents to 6 lx for sensitive humans. Even
lower, wavelength-dependent intensities are implied by some studies and require rigorous testing in ecological contexts. In many
studies, melatonin suppression occurs at the minimum light levels tested, and, in better-studied groups, melatonin suppression is
reported to occur at lower light levels. We identify major research gaps and conclude that, for most groups, crucial informat ion is
lacking. No studies were identified for amphibians and r eptiles and long-term impacts of low-level ALAN exposure are unknown.
Given the high sensitivity of vertebrate melatonin production to ALAN and the paucity of available information, it is crucial to
research impacts of ALAN further in order to inform effec tive mitigation strategies for human health and the wellbeing and
fitness of vertebrates in natural ecosystems.
Melatonin: a possible link between the presence of artificial light at night and reductions in biological fitness. Jones TM,
Durrant J, Michaelides EB, Green MP. 2015, Phil. Trans. R. Soc. B 370: 20140122.
https://royalsocietypublishing.org/doi/10.1098/rstb.2014.0122
Abstract: The mechanisms underpinning the ecological impacts of the presence of artificial night lighting remain elusive. One
suspected underlying cause is that the presence of light at night (LAN) supresses nocturnal production of melatonin, a key dr iver
of biological rhythm and a potent antioxidant with a proposed role in immune function. Here, we briefly review the evidence for
melatonin as the link between LAN and changes in behaviour and physiology. We then present preliminary data supporting the
potential for melatonin to act as a recovery agent mitigating the negative effects of LAN in an invertebrate. Adult crickets
(Teleogryllus commodus), exposed to constant illumination, were provided with dietary melatonin (concentrations: 0, 10 or 100
µg ml−1) in their drinking water. We then compared survival, li fetime fecundity and, over a 4-week period, immune function
(haemocyte concentration, lysozyme -like and phenoloxidase (PO) activity). Melatonin supplementation was able only partially to
mitigate the detrimental effects of LAN: it did not improve survival or fecundity or PO activity, but it had a largely dose -
dependent positive effect on haemocyte concentration and lysozyme -like activity. We discuss the implications of these
relationships, as well as the usefulness of invertebrates as model species for futu re studies that explore the effects of LAN.
Waters under Artificial Lights: Does Light Pollution Matter for Aquatic Primary Producers? Grubisic, M. (2018), Limnology
and Oceanography Bulletin, 27: 76-81.
https://aslopubs.onlinelibrary.wiley.com/doi/abs/10.1002/lob.10254
Abstract: Bright night lights have become a symbol of development and prosperity in the modern world. But have you ever
wondered how artificial light at night (ALAN) may be affecting living beings in our cities, and how it may be affecting us? As
artificial illumination is transforming nocturnal environments around the world, light pollution associated with its use is b ecoming
a topic of increasing interest in the scientific and public communities. Light pollution disrupts natural light regimes in many
regions of the world, raising concerns about ecological and health impacts of this novel anthropogenic pressure. Most obvious ly,
ALAN can influence night‐active animals in urban and suburban areas, and most research in this growing field focuses on
terrestrial organisms such as bats, birds, and insects. Effects on aquatic ecosystems are much less known. In particular, aqu atic
primary producers, such as microalgae, cyanobacteria, and plants, have rarely been studied despite their critical positioning in the
base of aquatic food webs and the fundamental role that light plays in their ecology. For primary producers, light is a key s ource
of both energy and environmental information; it influences their growth, production, and community structure. ALAN has
therefore a large potential to influence their communities and induce bottom‐up changes to aquatic ecosystems and ecosystem
functions.
Global climate change and invariable photoperiods: A mismatch that jeopardizes animal fitness. Walker, WH, Meléndez-
Fernández, OH, Nelson, RJ, Reiter, RJ. Ecol Evol. 2019; 9: 10044–10054.
https://onlinelibrary.wiley.com/doi/full/10.1002/ece3.5537
Abstract: The Earth's surface temperature is rising, and precipitation patterns throughout the Earth are changing; the source of
these shifts is likely anthropogenic in nature. Alterations in temperature and precipitation have obvious direct and indirect effects
on both plants and animals. Notably, changes in temperature and precipitation alone can have both advantageous and detrimenta l
consequences depending on the species. Typically, production of offspring is timed to coincide with optimal food availability;
thus, individuals of many species display annual rhythms of reproductive function. Because it requires substantial time to
establish or re-establish reproductive function, individuals cannot depend on the arrival of seasonal food availability to begin
breeding; thus, mechanisms have evolved in many plants and animals to monitor and respond to day length in order to anticipat e
seasonal changes in the environment. Over evolutionary ti me, there has been precise fine-tuning of critical photoperiod and
onset/offset of seasonal adaptations. Climate change has provoked changes in the availability of insects and plants which shi fts
the timing of optimal reproduction. However, adaptations to the stable p hotoperiod may be insufficiently plastic to allow a shift in
the seasonal timing of bird and mammal breeding. Coupled with the effects of light pollution which prevents these species fro m
determining day length, climate change presents extreme evolutionary pressure that can result in severe deleterious consequences
for individual species reproduction and survival. This review describes the effects of climate change on plants and animals,
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defines photoperiod and the physiological events it regulates, and add resses the consequences of global climate change and a
stable photoperiod.
Effects of street lighting technologies on the success and quality of pollination in a nocturnally pollinated plant. Macgregor, C.
J., M. J. O. Pocock, R. Fox, and D. M. Evans. 2019. Ecosphere 10(1):e02550
https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1002/ecs2.2550
Abstract: Artificial light at night (ALAN) is an increasingly important dr iver of global change. Lighting directly affects plants, but
few studies have investigated indirect effects mediated by interacting organisms. Nocturnal Lepidoptera are globally importan t
pollinators, and pollen transport by moths is disrupted by lighting. Many street lighting systems are being replaced with novel,
energy‐efficient lighting, with unknown ecological consequences. Using the wildflower Silene latifolia, we compared pollinati on
success and quality at experimentally lit and unlit plots, testing two major changes to street lighting technology: in lamp type,
from high‐pressure sodium lamps to light‐emitting diodes, and in lighting regime, from full‐night (FN) to part‐night (PN) lig hting.
We predicted that lighting would reduce pollination. S. latif olia was pollinated both diurnally and nocturnally. Contrary to our
predictions, flowers under FN lighting had higher pollination success than flowers under either PN lighting or unlit controls ,
which did not significantly differ from each other. Lamp type , lighting regime, and distance from the light all significantly
affected aspects of pollination quality. These results confirm that street lighting could affect plant reproduction through i ndirect
effects mediated by nocturnal insects, and further highlig ht the possibility for novel lighting technologies to mitigate the effects of
ALAN on ecosystems.
Cascading effects of artificial light at night: resource -mediated control of herbivores in a grassland ecosystem. Bennie J,
Davies TW, Cruse D, Inger R, Gaston KJ. 2015. Phil. Trans. R. Soc. B 370: 20140131.
https://royalsocietypublishing.org/doi/10.1098/rstb.2014.0131
Abstract: Artificial light at night has a wide range of biological effects on both plants and animals. Here, we review mechan isms
by which artificial light at night may restructure ecological communities by modifying the interactions between species. Such
mechanisms may be top-down (predator, parasite or grazer controlled), bottom-up (resource-controlled) or involve non-trophic
processes, such as pollination, seed dispersal or competition. We present results from an experiment investigating both top -down
and bottom-up effects of artificial light at night on the population density of pea aphids Acyrthosiphon pisum in a diverse
artificial grassland community in the presence and absence of predators and under low-level light of different spectral
composition. We found no evidence for top-down control of A. pisum in this system, but did find evidence for bottom-up effects
mediated through the impact of light on flower head density in a leguminous food plant. These results suggest that physiologi cal
effects of light on a plant species within a diverse plant community can have detectable demographic effects on a specialist
herbivore.
Artificial night light alters ecosystem services provided by biotic components. Singhal, R.K., Chauhan, J., Jatav, H.S. et al.
Biologia Futura (2021).
https://doi.org/10.1007/s42977-020-00065-x
Abstract Excerpt: This review highlights the impact of ALAN on the ecosystem and its living and non-living components,
emphasizing to the terrestrial and aquatic ecosystem. Further, we summarize the means of minimizing strategies of ALAN in the
environment, which are very crucial to reduce the further spread of night light contamination in the environment and can be u seful
to minimize the drastic impacts on the ecosystem.
City lights and urban air. Stark, H., Brown, S., Wong, K. et al. Nature Geoscience, Vol 4, Nov 2011.
https://doi.org/10.1038/ngeo1300
https://s3.amazonaws.com/wbez-assets/curiouscity/ngeo_1300_NOV11_auproof2.pdf
https://cires.colorado.edu/news/bright-city-lights-affect-air-pollution
Here we show that city lights can also alter the concentration of nitrate radicals, an important atmospheric oxidant. These
alterations have potential — albeit small — consequences for pollution levels the following day… We converted satellite data on
light intensity into nitrate radical loss, using our aircraft measurements, and show that the infuence of city lights on nitrate radical
loss can be large in regions outside Los Angeles... We also fnd that satellite-derived estimates of light levels tend to correlate
positively with independent satellite-derived estimates of nitrogen dioxide. We therefore suggest that city lights are likely to
infuence nitrogen dynamics in other regions o f the globe.
Nighttime photochemistry: nitrate radical destruction by anthropogenic light sources. Stark, H, etal. CIRES, NOAA. 2010.
https://www.academia.edu/23527679/Nighttime_photochemistry_nitrate_radical_destruction_by_anthropogenic_light_sources
Abstract extract: show airborne and ground measurements of absolute light intensities from anthropogenic and natural light
sources (e.g. industrial and street lighting, full moon) as a newly discovered NO3 loss process. This loss process has implic ations
for nighttime pollutant levels and next-day ozone production.
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Light Flicker from LED Lighting Systems-An Urgent Problem to Solve. GIES, T.H. (2016).
https://www.led-professional.com/resources-1/articles/lighting-flicker-from-led-lighting-systems/LpR53_p50-p59.pdf
Recent research has shown that fluctuations of short wavelength emissions are perceived to a higher extent and light flic ker may
have a huge influence on the well-being of end users.
Blue light excited retinal intercepts cellular signaling. Ratnayake, K., Payton, J.L., Lakmal, O.H. et al. Scientific Reports 8,
10207 (2018).
https://doi.org/10.1038/s41598-018-28254-8
Photoreceptor chromophore, 11-cis retinal (11CR) and the photoproduct, all-trans retinal (ATR), are present in the retina at higher
concentrations and interact with the visual cells. Non -visual cells in the body are also exposed to retinal that enters the circulation.
… we uncovered that blue light-excited ATR and 11CR irreversibly change/distort plasma membrane (PM) bound phospholipid;
phosphatidylinositol 4,5 bisphosphate (PIP2) and disrupt its function. … The change in PIP2 was followed by an increase in the
cytosolic calcium, excessive cell shape change, and cell death… These findings suggest that retinal exerts light sensitivity to both
photoreceptor and non-photoreceptor cells, and intercepts crucial signaling events, altering the cellular fate.
Blue light from phone screens accelerates blindness, study finds. The Guardian. 8/9/2018
https://www.theguardian.com/society/2018/aug/09/blue-light-from-phone-screens-accelerates-blindness-study-finds
Research… has revealed that prolonged exposure to blue light triggers poisonous molecules to be generated in the eye’s light -
sensitive cells that can cause macular degeneration – an incurable condition that affects the middle part of vision. Blue light,
which has a shorter wavelength and more energy compared with other colours, can gradually cause damage to the eyes.
How the marvel of electric light became a global blight to health. Dr. Richard G ‘Bugs’ Stevens. Aeon. August 3, 2018.
https://aeon.co/ideas/how-the-marvel-of-electric-light-became-a-global-blight-to-health
Excerpts: Light at night constitutes a massive assault on the ecology of the planet, including us… The electric light bulb is touted
as one of the most significant technological advancements of human beings… But as with any new and spectacular technology,
there are invariably unintended consequences… 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 t he
roads turned out to increase congestion and pollution, including light pollution, too… More efficient energy-production and use,
without concerted public education on reduction of use, can make the pollution problem worse… 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’… In response to this relentless attack on night, the American Medical Association (AMA) stepped up and
adopted an official policy statement in 2016... 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… few people will leave the faucet running much longer than
necessary. Yet some people think nothing of using more electricity than they actually need… In the life of the planet, destruction
of night is as important an issue as the poisoning of water and air.
Artificial Light at Night (ALAN): A Potential Anthropogenic Component for the COVID-19 and HCoVs Outbreak. Khan ZA,
Yumnamcha T, Mondal G, et al. Frontiers in endocrinology. 2020;11:622. Published 2020 Sep 10.
https://www.frontiersin.org/articles/10.3389/fendo.2020.00622 /full
Abstract Excerpt: In this article, we tried to focus on the possible influence of this anthropogenic factor in human coronavirus
(HCoV) outbreak. The relationship between the occurrences of coronavirus and the ascending curve of the night -light has also
been delivered. The ALAN influences the physiology and behavior of bat, a known nocturnal natural reservoir of many
Coronaviridae. The “threatened” and “endangered” status of the majority of bat species is mainly because of the destruction o f
their proper habit and habitat predominantly through artificial illumination. The stress exerted by ALAN leads to the impaired
body functions, especially endocrine, immune, genomic integration, and overall rhythm features of different physiological
variables and behaviors in nocturnal animals. Night-light disturbs “virus–host” synchronization and may lead to mutation in the
genomic part of the virus and excessive virus shedding. We also proposed some future strategies to mitigate the repercussions of
ALAN and for the protection of the living system in the earth as well.
Light pollution linked to preterm birth increase. Jan 25, 2021. Lehigh University. Science Daily.
https://www.sciencedaily.com/releases/2021/01/210125191821.htm
Scientists conducted the first study to examine the fetal health impact of light pollution based on a direct measure of skyglow, an
important aspect of light pollution. Using an empirical regularity discovered in physics, called Walker's Law, a team found
evidence of reduced birth weight, shortened gestational length and preterm births.
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Association of Outdoor Artificial Light at Night With Mental Disorders and Sleep Patterns Among US Adolescents. Paksarian
D, Rudolph KE, Stapp EK, et al. JAMA Psychiatry. 2020;77(12):1266–1275.
https://jamanetwork.com/journals/jamapsychiatry/article-abstract/2767698
https://edition.cnn.com/2020/07/08/health/night-light-pollution-disrupt-sleep-wellness/index.html
In this study, area-level outdoor ALAN was associated with less favorable sleep patterns and mood and anxiety disorder in
adolescents. Future studies should elucidate whether interventions to reduce exposure to ALAN may positively affect mental and
sleep health.
Astronomy Impacts
Light Pollution In California And Arizona. Walker, Merle F. Publications of The Astronomical Society of The Pacific, Vol. 85,
No. 507, 1973, pp. 508–519. Jstor
http://www.jstor.org/stable/40675430
The present and future effect of artificial illumination on ground -based optical astronomical observations in California and
Arizona is discussed. It is concluded that the effectiveness of all major observatories in these states is presently or potentially
limited by light pollution. Consequently, it is essential that immediate efforts be undertaken to: (1) Control outdoor illumi nation
to lengthen the useful life of existing observatory sites, and (2) Identify and protect the best remaining sites both within and
outside the United States. The characteristics and probable locations of the best sites for ground -based optical astronomical
observations are discussed.
Light Pollution: Outdoor lighting is a growing threat to astronomy. Riegel, Kurt W. Science, Vol. 179, No. 4080, Mar 1973, pp.
1285–1291.
https://pubmed.ncbi.nlm.nih.gov/17835929/
Abstract Excerpt: The level of skylight caused by outdoor lighting systems is growing at a very high rate, about 20 percent per
year nationwide. In addition, the spectral distribution of man -made light pollution may change in the next decade from one
containing a few mercury lines to one containing dozens of lines and a significantly increased continuum level. Light pollution is
presently damaging to some astronomical programs, and it is likely to become a major factor limiting progress in the next
decade... Some is due to promotional campaigns, in which questionable arguments involving public safety are presented. There
are protective measures which might be adopted by the government; these would significantly aid observational astronomy,
without compromising the legitimate outdoor lighting needs of society.
Flagstaff's Battle for Dark Skies. Portree D.S.F. Oct 2002, Griffith Observer, Vol 66 No 10
http://www2.lowell.edu/users/wes/GriffithObserver1crop.pdf
http://www.flagstaffdarkskies.org/international-dark-sky-city/flagstaffs-battle-for-dark-skies/
Public Safety
Blinded by the Lights: Levi's Stadium Lights May Be Airport Safety Hazard. By Stephen Stock, Michael Bott and Jeremy
Carroll. NBC Bay Area. Sept 22, 2015
https://www.nbcbayarea.com/news/local/blinded-by-the-lights-levi-stadium-lights-may-be-airport-safety-hazard/102234/
Some pilots say powerful lights above and around the new Levi’s Stadium can cause safety hazards for flights in and out of Sa n
Jose Mineta International Airport.
Why Lighting Claims Might Well Be Wrong, Paul Marchant, International Journal of Sustainable Lighting: Vol. 19 No. 1 (2017)
http://lightingjournal.org/index.php/path/article/view/71/79
This paper gives some background to claims of benefit from road lighting and why large beneficial claims may be suspect.
Feeling Safe in the Dark: Examining the Effect of Entrapment, Lighting Levels, and Gender on Feelings o f Safety and
Lighting Policy Acceptability. Boomsma C, et al. Environmental and Behavior, Vol 46 Issue 2, pp 193 -212. Sept 2012.
https://journals.sagepub.com/doi/10.1177/0013916512453838
Importantly, as hypothesized, perceived safety mediated the effect of lighting on acceptability levels, suggesting that peopl e can
accept lower lighting levels when social safety is not threatened.
The effect of reduced street lighting on road casualties and crime in England and Wales: controlled interrupted time series
analysis. Steinbach R, Perkins C, Tompson L, et al, J Epidemiol Community Health 2015;69:1118 -1124.
https://jech.bmj.com/content/69/11/1118
Conclusions: This study found little evidence of harmful effects of switch off, part-night lighting, dimming, or changes to white
light/LEDs on road collisions or crime in England and Wales.
11
Light Pollution Mitigation
National Light Pollution Guidelines for Wildlife Including Marine Turtles, Seabirds and Migratory Shorebirds ,
Commonwealth of Australia, Jan 2020
https://www.environment.gov.au/biodiversity/publications/national -light-pollution-guidelines-wildlife
Audubon’s Lights Out program
https://www.audubon.org/conservation/project/lights-out
LoNNe, Loss of the Night Network
http://www.cost-lonne.eu/recommendations/
Human and Environmental Effects of Light Emitting Diode (LED) Community Lighting , 2016, American Medical Association,
CSAPH Report 2-A-16, Policy H-135.927
https://policysearch.ama-assn.org/policyfinder/detail/H-135.927?uri=%2FAMADoc%2FHOD-135.927.xml
https://www.ama-assn.org/sites/ama-assn.org/files/corp/media-browser/public/about-ama/councils/Council%20Reports/council-
on-science-public-health/a16-csaph2.pdf
supports the proper conversion to community-based Light Emitting Diode (LED) lighting, which reduces energy consumption
and decreases the use of fossil fuels.. encourages minimizing and controlling blue-rich environmental lighting by using the lowest
emission of blue light possible to reduce glare... should be properly shielded to minimize glare and detrimental human and
environmental effects, and... utilize the ability of LED lighting to be dimmed for off -peak time periods.
Advocating and Support for Light Pollution Control Efforts and Glare Reduction for Both Public Safety and Energy Savings ,
2012, Policy H-135.937
https://policysearch.ama-assn.org/policyfinder/detail/light%20pollution?uri=%2FAMADoc%2FHOD.xml -0-308.xml
Our AMA: (1) will advocate that all future outdoor lighting be of energy efficient designs to reduce waste of energy and
production of greenhouse gasses that result from this wasted energy use; (2) supports light pollution reduction efforts and g lare
reduction efforts at both the national and state levels; and (3) supports efforts to ensure all future streetlights be of a fully shielded
design or similar non-glare design to improve the safety of our roadways for all, but especially vision impaired and older drivers.
International Dark-Sky Association, https://darksky.org, https://darksky.org/light-pollution
IDA Guidance for Electronic Message Centers (EMCs) – Digital billboards
https://www.darksky.org/wp-content/uploads/2019/10/EMC-Guidelines-IDA2019-1.1.pdf
IDA Criteria for Community-Friendly Outdoor Sports Lighting
https://www.darksky.org/wp-content/uploads/2018/03/IDA-Criteria-for-Community-Friendly-Outdoor-Sports-Lighting.pdf
Model Lighting Ordinances – Dark Sky Impacts, Flagstaff Dark Skies Coalition
http://www.flagstaffdarkskies.org/model-lighting-ordinances-dark-sky-impacts/
Led Lighting And Dark Skies: Are LEDs good for dark skies? Flagstaff Dark Skies Coalition.
http://www.flagstaffdarkskies.org/led-lighting-dark-skies/
Light Pollution and Lighting Codes: An Analysis of the Light Pollution Control Effectiveness of the IDA-IES Model Lighting
Ordinance and the IDA Pattern Outdoor Lighting Code, Christian B. Luginbuhl, U.S. Naval Observatory Flagstaff Station, 15
January 2013
http://www.flagstaffdarkskies.org/wp-content/uploads/2013/02/Lighting-Codes-and-LP-Luginbuhl-130115.pdf
Excerpts: Under MLO standards, outside of MLO Lighting Zones 0 and 1, the total lumen allowances, direct uplight allowances,
and amount of sky glow are notably greater than expected under POLC standards; in MLO Lighting Zones 3 and 4 they are
dramatically greater. These lighting amounts and sky glow impacts are greater than what can be expected even when lighting is
unregulated. The MLO Performance Method Option B provides notably poor control of direct upl ight and therefore sky glow.
Under the MLO Performance Method Option B there are no effective limitations on glare. MLO does not address lamp spectrum,
and thus leaves this crucial aspect of light pollution unaddressed. Finally, the analysis shows that the MLO Prescriptive
Hardscape Area and Performance Methods do not provide similar results in terms of total lumen a mounts, uplight amounts, glare,
or “offsite” impacts, an undesirable characteristic of a model regulation purporting to control light pollution. The Performa nce
Method particularly allows for the most egregious forms of polluting lighting fixtures and designs. We find no evidence that
communities adopting MLO can expect reduction in light pollution over that produced by typical unregulated lighting, despite the
claims of MLO to be a method to “drastically reduce” light pollution.
12
Model Lighting Ordinance: Is the BUG rating method effective at limiting light trespass?, April/May 2012 issue of LEDs
Magazine
https://www.ledsmagazine.com/architectural-lighting/outdoor-lighting/article/16698628/model-lighting-ordinance-is-the-bug-
rating-method-effective-at-limiting-light-trespass-magazine
Excerpts: The MLO allows for the use of BUG ratings along with the performance method as long as there is no uplight used.
This scenario would not only allow for more lumens on the site as compared to the prescriptive method, but also would allow f or
a greater amount of light spilling from the site than would be seen from sites that restrict the spill by using the calculation method.
As proven from the studies done for this article, the BUG rating method cannot effectively control these extra lumens of spil l
light.
Hazard or Hope? LEDs and Wildlife. Longcore, Travis. (2018). LED Professional Review. 70. 52 -57.
https://www.led-professional.com/resources-1/articles/hazard-or-hope-leds-and-wildlife
Conclusions: The efficiency benefits of LEDs and the resulting economic incentives will drive further conversion of outdoor a nd
indoor lighting to the technology. If the tendency to light more when light is cheaper can be overcome, th e other attributes of
LEDs hold significant promise for reducing environmental effects. Realizing that promise requires designers and manufacturers to
learn about and embrace the guidance that wildlife scientists can provide. In some instances it will be c hallenging - resisting the
desire to up-light, using no more light than necessary, and educating clients on the benefits of spectral choices that do not look
like daylight. In other contexts, environmental regulations are likely to dictate lighting choices and offer an opportunity if the
industry is prepared to seize it. On each of the mitigation approaches - duration, direction, intensity, and spectrum - LEDs will
inherently or can be designed to perform well. Whether they do in practice will be up to the LED professional.
Artificial Night Lighting and Protected Lands: Ecological Effects and Management Approaches (Revised August 2017).
Longcore, T., and C. Rich. Natural Resource Report NPS/NRSS/NSNS/NRR —2017/1493. National Park Service, Fort Collins,
Colorado.
https://irma.nps.gov/DataStore/DownloadFile/582058
Artificial night lighting represents a growing challenge for managers of parks and protected lands. The disruption of natural
patterns of light and dark, which have been more or less reliable for millions of years, has a range of adverse consequences for
wildlife across taxonomic groups and landscape types. This document reviews effects of artificial night lighting by habitat t ype
and discusses the approaches available to land managers to mitigate and avoid certain adverse effects of artificial night lighting .
Rapid assessment of lamp spectrum to quantify ecological effects of light at night. Longcore, T., A. Rodríguez, B.
Witherington, J. F. Penniman, L. Herf, and M. Herf. 2018. Journal of Experimental Zoology A 329:511 -521.
https://onlinelibrary.wiley.com/doi/abs/10.1002/jez.2184
Abstract: For many decades, the spectral composition of lighting was determined by the type of lamp, which also influenced
potential effects of outdoor lights on species and ecosystems. Light-emitting diode (LED) lamps have dramatically increased the
range of spectral profiles of light t hat is economically viable for outdoor lighting. Because of the array of choices, it is necessary
to develop methods to predict the effects of different spectral profiles without conducting field studies, especially because older
lighting systems are being replaced rapidly. We describe an approach to predict responses of exemplar organisms and groups to
lamps of different spectral output by calculating an index based on action spectra from behavioral or visual characteristics of
organisms and lamp spectral irradiance. We calculate relative response indices for a range of lamp types and light sources and
develop an index that identifies lamps that minimize predicted effects as measured by ecological, physiological, and astronom ical
indices. Using these assessment metrics, filtered yellow-green and amber LEDs are predicted to have lower effects on wildlife
than high pressure sodium lamps, while blue -rich lighting (e.g., K ≥ 2200) would have greater effects. The approach can be
updated with new information about behavioral or visual responses of organisms and used to test new lighting products based on
spectrum. Together with control of intensity, direction, and duration, the approach can be used to predict and then minimize the
adverse effects of lighting and can be tailored to individual species or taxonomic groups.
The LED Paradox: How Light Pollution Challenges Experts to Reconsider Sustainable Lighting. Schulte-Römer, N.; Meier, J.;
Söding, M.; Dannemann, E.; Sustainability 2019, 11, 6160.
https://www.mdpi.com/2071-1050/11/21/6160
Abstract: In the 21st century, the notion of “sustainable lighting” is closely associated with LED technology. In the past te n years,
municipalities and private light users worldwide have installed light-emitting diodes in urban spaces and public streets to save
energy. Yet an increasing body of interdisciplinary research suggests that supposedly sustainable LED installations are in fa ct
unsustainable, because they increase light pollution. Paradoxically, blue-rich cool-white LED lighting, which is the most energy-
efficient, also appears to be the most ecologically unfriendly. Biologists, physicians and ecologists warn that blue -rich LED light
disturbs the circadian day-and-night rhythm of living organisms, including humans, with potential negative health effects on
individual species and whole ecosystems. Can the paradox be solved? This paper explores this question based on our
transdisciplinary research project Light Pollution—A Global Discussion. It reveals how light pollution experts and lighting
professionals see the challenges and potential of LED lighting from their different viewpoints. This expert feedback shows th at
“sustainable LED lighting” goes far beyond energy efficiency as it raises complex design issues that imply stakeholder
negotiation. It also suggests that the LED paradox may be solved in context, but hardly in principle.
13
Tuning the white light spectrum of light emitting diode lamps to reduce attraction of noc turnal arthropods. Longcore Travis,
Aldern Hannah L., Eggers John F., Flores Steve, Franco Lesly, Hirshfield -Yamanishi Eric, Petrinec Laina N., Yan Wilson A.
and Barroso André M. 2015, Phil. Trans. R. Soc. B37020140125
https://royalsocietypublishing.org/doi/abs/10.1098/rstb.2014.012 5
Abstract: Artificial lighting allows humans to be active at night, but has many unintended consequences, including interferen ce
with ecological processes, disruption of circadian rhythms and increased exposure to insect vectors of diseases. Although
ultraviolet and blue light are usually most attractive to arthropods, degree of attraction varies among orders. With a focus on
future indoor lighting applications, we manipulated the spectrum of white lamps to investigate the influence of spectral
composition on number of arthropods attracted. We compared numbers of arthropods captured at three customizable light -
emitting diode (LED) lamps (3510, 2704 and 2728 K), two commercial LED lamps (2700 K), two commercial compact
fluorescent lamps (CFLs; 2700 K) and a control. We configured the three custom LEDs to minimize invertebrate attraction based
on published attraction curves for honeybees and moths. Lamps were placed with pan traps at an urban and two rural study sites
in Los Angeles, California. For all invertebrate orders combined, our custom LED configurations were less attractive than the
commercial LED lamps or CFLs of similar colour temperatures. Thu s, adjusting spectral composition of white light to minimize
attracting nocturnal arthropods is feasible; not all lights with the same colour temperature are equally attractive to arthro pods.
Evaluating Potential Spectral Impacts of Various Artificial Lights on Melatonin Suppression, Photosynthesis, and Star
Visibility. Aubé M, Roby J, Kocifaj M (2013). PLOS ONE 8(7): e67798.
https://doi.org/10.1371/journal.pone.0067798
Abstract Excerpt: Artificial light at night can be harmful to the environment, and interferes with fauna and flora, star visibility,
and human health. To estimate the relative impact of a lighting device, its radiant power, angular photometry and detailed sp ectral
power distribution have to be considered. In this paper we focus on the spectral power distribution... In this paper we propose
three new indices to characterize lamp spectra. These indices have been designed to allow a quick estimation of the potential
impact of a lamp spectrum on melatonin suppression, photosynthesis, and star visibility. We used these new indices to compare
various lighting technologies objectively. We also considered the transformation of such indices according to the propagation of
light into the atmosphere as a function of distance to the observer. Among other results, we found that low pressure sodium,
phosphor-converted amber light emitting diodes (LED) and LED 2700 K lamps filtered with the new Ledtech’s Equilib filter
showed a lower or equivalent potential impact on melatonin suppression and star visibility in comparison to high pressure sodium
lamps. Low pressure sodium, LED 5000 K-filtered and LED 2700 K-filtered lamps had a lower impact on photosynthesis than did
high pressure sodium lamps. Finally, we propose these indices as new standards for the lighting industry to be used in
characterizing their lighting technologies.
Solid-State Roadway Lighting Design Guide: Volume 1: Guidance. National Academies of Sciences, Engineering, and
Medicine. 2020. https://doi.org/10.17226/25678
Solid-State Roadwazy Lighting Design Guide: Volume 2: Research Overview. National Academies of Sciences, Engineering,
and Medicine. 2020. https://doi.org/10.17226/25679
Assessment of Citizens’ Actions against Light Pollution with Guidelines for Future Initiatives. Zielińska-Dabkowska, K.M.;
Xavia, K.; Bobkowska, K. Sustainability. June 2020, 12, 4997.
https://doi.org/10.3390/su12124997
Abstract excerpt: This paper therefore investigates the various actions taken by citizens, as well as the challenges, methods, and
tools involved, regarding good practices initiated by grass roots activism on how to reduce existing and potential light pollution.
The results of a comparative analysis of 262 international case studies (lawsuits and online petitions) reveal that, since th e 1990s,
there has been an increase in the number of legal cases related to light pollution due to the rise in public awareness, the
availability of scientific knowledge via the Internet, and the ability to take accurate lighting measurements and perform lig hting
simulations. Also, in the last decade a new tool for digital participation in the form of online petitions has established a new
movement of citizen action to mitigate the effects of light pollution. Based on this information, a seven -step framework involving
recommendations for citizen action has been developed. It is expected that this new knowledge will benefit those citizens
planning future efforts involving the development, implementation, and monitoring processes of outdoor lighting. Additionally , it
might support the evolution of planning and policy approaches that are sustainable and necessary to improve the application and
installation of ecologically/biologically responsible illumination for towns, cities, and natural habitats.
Nevada Senate passes bill to form ‘dark sky places’ program. Feb 22, 2021. By Sam Metz, AP News
https://apnews.com/article/legislature-nevada-light-pollution-coronavirus-pandemic-kate-marshall-
eb0f69ee3c5895b1f7dd4d89b1ea3ebc
Nevada’s state Senate took a step toward ensuring stargazers will continue to enjoy picture -perfect constellations on Monday,
passing a bill to recognize “dark sky places” with unobstructed views of galaxies hundreds of thousands of light years away.
14
Urban Lighting Research Transdisciplinary Framework—A Collaborative Process with Lighting Professionals. Pérez Vega,
C.; Zielinska-Dabkowska, K.M.; Hölker, F. Int. J. Environ. Res. Public Health. 2021, 18, 624.
https://doi.org/10.3390/ijerph18020624
Abstract Excerpt: Over the past decades, lighting professionals have influenced the experience of the night by brightly
illuminating streets, buildings, skylines, and landscapes 24/7... a dual perspective on night-time was shaped and the visual
enjoyment of visitors after dusk was prioritized over natural nightscapes (nocturnal landscapes). During this time, researche rs of
artificial light at night (ALAN) observed and reported a gradual increase in unnatural brightness and a shift in color of the night -
time environment. As a consequence, ALAN has been identified as a relevant pollutant of aquatic and terrestrial habitats, and an
environmental stressor, which may adversely affect a wide range of organisms, from micro -organisms to humans... This paper
presents a framework to help reduce the existing gap of knowledge, because appropriate lighting applications depend upon it.
Access to less light polluted nightscapes in urban environments is just as important as access to unpolluted water, food, and air.
On-line Workshop “Dark and Quiet Skies for Science and Society", Report and Recommendations, Dec 2020, coordinated by
the United Nations Office for Outer Space Affairs
https://unoosa.org/oosa/en/ourwork/psa/schedule/2020/2020_dark_skies.html
to propose to COPUOS [United Nations Committee on the Peaceful Uses of O uter Space]... recommendations, to be acted upon
either by local governments or agreed to at an international level... This report analyses all artificial interference that c an have a
negative impact on the visibility of the night sky. These interferences can be logically grouped into three categories... effect
caused by the artificial emission of visible light during the night,... impact that the very large number of communication sa tellites
in Low Earth Orbit... to the interference that radio broadcasting... have on observations by radio telescopes.
Grasping darkness: the dark ecological network as a social-ecological framework to limit the impacts of light pollution on
biodiversity. Challéat, S., et al. 2021. Ecology and Society 26(1):15.
https://doi.org/10.5751/ES-12156-260115
Abstract excerpt: Artificial light at night (ALAN)... is increasingly recognized as a major threat to global biodiversity, which
ultimately alters the amount, the quality, and the connectivity of available habitats for taxa... Here we present the concept of “dark
ecological network.” We show this concept is able to grasp the effects of ALAN in terms of habitat disturbances and integrate s
temporal dimensions of ecological processes into biodiversity conservation planning... we propose a course of action that consists
of building an interdisciplinary repertoire of contextualized knowledge (e.g., impacts on wildlife, human/lightscape relation ship,
existing legal tools, etc.), in order to deduce from it a number of practical supports for the governance of the dark ecological
network in response to societal and ecological issues.
Phase II Digital Billboard Survey
March 17 2021
City of San Jose Survey: Digital Billboards
Phase 2: Sign Code Changes for Off-Site
Advertising, Electronic Billboards and signs
displaying off-site commercial speech on non-
City-owned sites
March 2021
www.sanjoseca.gov/planning
City of San Jose Survey: Digital Billboards
Images are for illustrative purposes only
Survey Link:
https://bit.ly/SignOrdinanceUpdate
Survey Start date: February 8, 2021
Survey End Date: March 12, 2021
Data retrieved: March 17, 2021
Current Responses: 2234 (English)
4 (Spanish)
0 (Vietnamese)2
Phase II Digital Billboard Survey
March 17 2021
www.sanjoseca.gov/planning
City of San José Survey: Digital Billboards
Images are for illustrative purposes only
I live in San José
I work in San José
I own or represent a business in
San José
I own or represent a commercial
or industrial property in San José
I represent a sign company in
San José
I am part of an environmental
advocacy group or other similar
organization
Other (please specify)
Responses: 2226
Skipped: 8 3
Item 1: Tell us about yourself (check all that apply): *Required
www.sanjoseca.gov/planning
City of San José Survey: Digital Billboards
Images are for illustrative purposes only
Item 2: Let us know how close you live to a billboard (check all that apply):
*Required
I can see a billboard from
my home
I can see a billboard from
my block
There is a billboard in my
neighborhood
There are lots of billboards
in my neighborhood
There are no billboards in
my neighborhood
Responses: 2175
Skipped: 59 4
Phase II Digital Billboard Survey
March 17 2021
www.sanjoseca.gov/planning
City of San José Survey: Digital Billboards
Images are for illustrative purposes only
Item 3: In general, how do you feel about allowing new digital billboards to be
built along freeways in San José?
Strongly
opposed
Somewhat
opposed
Neutral
Somewhat in
favor
Strongly in
favor
Responses: 2230
Skipped: 4 5
www.sanjoseca.gov/planning
City of San José Survey: Digital Billboards
Images are for illustrative purposes only
Item 4: How do you feel about allowing new digital billboards to be built along
freeways in San José in exchange for removing old billboards from elsewhere
in the city?
Strongly
opposed
Somewhat
opposed
Neutral
Somewhat in
favor
Strongly in
favor
Responses: 2226
Skipped: 8 6
Phase II Digital Billboard Survey
March 17 2021
www.sanjoseca.gov/planning
City of San José Survey: Digital Billboards
Images are for illustrative purposes only
Item 5: In addition to removing old billboards, is there anything that you would
like to see the City require in order for a property owner to be allowed to install
a new digital billboard?
•Driving distraction related to light and motion
•Brightness concerns and visual pollution
•Not recommended near freeways
•Not recommended near residences
•No political advertising
•Community messaging allowed atleast 25% of the timeResponses: 1372
Skipped: 862 7
www.sanjoseca.gov/planning
City of San José Survey: Digital Billboards
Images are for illustrative purposes only
Item 6: If new digital billboards are allowed in exchange for removing old
billboards, how many old billboards do you think should have to be removed
in exchange for one new digital billboard?
3 or fewer
4
5
6
7
8
9
10
More than 10Responses: 1935
Skipped: 299 8
Phase II Digital Billboard Survey
March 17 2021
www.sanjoseca.gov/planning
City of San José Survey: Digital Billboards
Images are for illustrative purposes only
Age of billboard
Condition/maintenance
of billboard
Visibility of billboard from
residences
Visibility of billboard from
a freeway
Visibility of the billboard
from a major (street or
business district
Size of the billboard
Other (please specify)
Item 7: In your opinion, what is the most important factor when evaluating
which billboards should be removed in exchange for allowing new ones?
Responses: 2058
Skipped: 176 9
www.sanjoseca.gov/planning
City of San José Survey: Digital Billboards
Images are for illustrative purposes only
Item 8: The most common concerns we have heard about potentially allowing
new digital billboards and signs are: 1) light pollution, 2) impacts to wildlife, 3)
traffic and pedestrian safety, 4) aesthetics/visual clutter. Do you have other
concerns you want us to know about?
•Distraction to motorists
•Brightness and other impacts to residents
•Quality of life and health concerns
•Commercialism over community image
Responses: 1235
Skipped: 999 10
Phase II Digital Billboard Survey
March 17 2021
www.sanjoseca.gov/planning
City of San José Survey: Digital Billboards
Images are for illustrative purposes only
Item 9: The proposal under consideration is to allow digital billboards on
properties that front freeways. Are there any freeway segments where you
think new digital billboards are MOST appropriate? Please be as descriptive as
possible (for example, Highway 101 between McKee Road and Interstate 880):
•Brightness and light pollution impacts
•Safety hazard and driver distraction
•80% of the comments opposed to freeway-facing billboards
•Siting along industrial properties and storage facilities
Responses: 1187
Skipped: 1047 11
www.sanjoseca.gov/planning
City of San José Survey: Digital Billboards
Images are for illustrative purposes only
Item 10: Are there any freeway segments where you think new digital
billboards are LEAST appropriate? Please be as descriptive as possible:
•Not appropriate or desired for any location
•Not near freeway interchanges, ramps and junctions
•Not near traffic corridors or zones of high fatality
•No billboard closer than 20 miles from another billboard
•No impacts to green spaces or residents
Responses: 1323
Skipped: 911 12
Phase II Digital Billboard Survey
March 17 2021
www.sanjoseca.gov/planning
City of San José Survey: Digital Billboards
Images are for illustrative purposes only
Item 11: In addition to free-standing digital billboards along freeways, the City
is considering allowing both digital and static advertising signs attached to
buildings within the Downtown. How do you feel such signs being attached to
buildings in Downtown San José?
Strongly
opposed
Somewhat
opposed
Neutral
Somewhat in
favor
Strongly in
favor
Responses: 2203
Skipped: 31 13
www.sanjoseca.gov/planning
City of San José Survey: Digital Billboards
Images are for illustrative purposes only
Item 12: To help us evaluate this proposal, do you have any specific concerns
about digital and static signs attached to buildings?
Aesthetics/visual
clutter
Light pollution/impacts
to wildlife
Traffic and pedestrian
safety
Compatibility with
historic
buildings/districts
Sign content
Other
Responses: 2184
Skipped: 50 14
Phase II Digital Billboard Survey
March 17 2021
www.sanjoseca.gov/planning
City of San José Survey: Digital Billboards
Images are for illustrative purposes only
Item 13: Is there anything else you'd like to tell us?
•80% of the comments opposed to all forms of billboards
•Traffic safety, wildlife impacts, aesthetics and brightness
concerns
•New static or digital billboards not recommended
•Maintain San Jose’s clean and green character
•Keep freeways free of digital distraction, reduce visual clutter
and support Vision Zero
Responses: 1181
Skipped: 1053 15
Illuminating the Issues
Digital Signage and
Philadelphia’s Green Future
by Gregory Young
In the world of outdoor advertising, successive technological and stylistic advancements
have prompted cities and states to rethink their signage regulation and policy. There has
been much controversy regarding the potential safety hazard posed by digital signage.
Many studies show that such signage can lead to driver distraction and traffic delays
(Wachtel, 2009). This research, and the resultant outcry from activists and concerned
citizens, has led some policymakers to regulate distracting, electronic signage displays.
There has been relatively little research, however, regarding the environmental and
energy-consumption issues raised by this new technology.
The Basics of Digital Signage and Energy Consumption
First, what exactly is digital signage? Digital signage packages consist of three key
pieces: player, extender(s), and display. The player is essentially a computer, equipped
with software to generate the displayed content. Players are typically mounted behind the
screen, and must be kept cool (via internal or accessory fan) and must be easily accessible
for repairs or rebooting. These player/fan arrangements typically consume between 200
and 300 Watts 1 while running, slightly more than a home dishwasher. Depending on the
relative location of the player to the screen, there may be a need for a video extender,
essentially a cable which connects the player to the screen. This brings us to the most
important component of any digital sign: the screen, or, in industry parlance, “the
display.” There are three main categories of digital display: LCD, plasma, and LED.
1 Watt—a unit of power which measures the rate of energy conversion. It is defined as one joule per second. The
kilowatt (kW) is equal to one thousand watts. For a sense of perspective, one kilowatt of power is approximately equal
to 1.34 horsepower. A small electric heater with one heating element can use 1.0 kilowatt. If that heater is used for one
hour, it will have used one kilowatt hour.
LED is the name used for Light Emitting Diode
(aka LED) boards, commonly used in small to
medium sized on-premise electronic advertising2 .
They are the overwhelming preference for large
off-premise 3 digital billboards; designed for long-
distance impact, they are often up to 1200 sq. ft. in
size (20’x60’). According to the U.S. Department
of Energy, LEDs produce more light (in lumens
per watt) than incandescent bulbs, and their
efficiency is not affected by shape and size, unlike
traditional fluorescent light bulbs or tubes.
Proponents of digital signage tout the “greenness”
of LEDs; lower wattage and greater luminance 4
than the more traditional fluorescent,
incandescent, or halogen bulbs.
State Rd. & Academy Rd., Philadelphia
Off-premise LED sign
These claims overlook one key bit of common
sense: whereas traditional, static signage is
illuminated by two or three “inefficient” lamps at
nighttime, digital signs are comprised of
hundreds, if not thousands, of “green” LED bulbs,
each using between 2-10 watts, lit twenty-four
hours a day. For instance, a 14’x48’ LED
billboard can have between 900 and 10,000
diodes.
Considering this simple fact, intrinsic to digital
billboard design, it is no surprise that overall
energy consumption of digital signage exceeds
that of static signage, and makes bulb-to-bulb
comparisons irrelevant in this context.
3051 Front St., Philadelphia
Off-premise LED sign
Additionally, with all digital display types, the players which control the changeable
images and the fans required to cool them must be taken into account, as they too
increase energy consumption. Adding auxiliary equipment, such as extenders, further
increases the power demand.
2 On-premise or accessory signage is defined as a business establishment’s on-site advertisements.
3 Off-premise or non-accessory billboards/signs are those which advertise a business or product not sold at
the signs’ location. Roadside billboards are a popular form of off-premise advertising.
4 Luminance is a measure of the perceived brightness of a light-emitting surface, such as a digital sign. Its unit of
measure is candela per square meter (c/m2), informally referred to as “nits.”
2
Determining the exact power consumption for a digital billboard is difficult; usage is
dependent upon many variables, including size, resolution (how close pixels are spaced,
aka diode density), how many LEDs are in each pixel, the color capabilities of the board
(tri-color or full color), the image being displayed and time of day (daytime operation
requires more power than nighttime operation, as the lit image must compete with the
brightness of the sun). Despite these difficulties, we have compiled an objective chart of
consumption rates. Our information was provided by a variety of sources, ranging from
manufacturers, fellow researchers, advocacy groups, and independent meter readings.
Static
Billboard
(4)
Halide
Lamps -
calculat
ed
static
billboard
(L.A.
Reading
)
Static
billboard
(Johnso
n actual
reading)
Average
US
home
LED
Billboard
(L.A.
Reading
)
Barco
LED
Lighthou
se
LVP205
6
AGX
digital
14' x 48
'
billboard
14' x 48'
LED
Billboard
(Johnso
n actual
reading)
EraLED
Series
P20
Billboard
ThinkSig
n LED
Optec
Displays
LED
0
50,000
100,000
150,000
200,000
250,000
300,000
350,000
Approximate Annual Energy Usage for Billboards
Static vs. LED
Kilowatt Hours
LED units generate heat, and cannot function well in heat which reduces the unit's life
expectancy. As a result of the tremendous amount of heat generated in LEDs , and the
additional impact of hot weather on the signs, an air conditioning unit is incorporated to
cool the components. The energy drawn from the grid is highest during the summer
months when the heat from the sun coupled with the heat generated by the higher
brightness of the LED unit requires increased demand on the air conditioning system
installed for cooling the LED unit. This energy use corresponds directly with maximum
peak demands from businesses and residences. Utility companies now provide a discount
for homeowners if they can disconnect their air conditioners from the grid during the
peak load demands. There is no discussion or plan that we are aware of to disconnect
LED air conditioners or darken signs during periods of high demand. If traditional
billboards continue to be replaced by LED signs, the growing draw of energy during peak
hours could negate the efforts of Utility companies to reduce demand during peak times.
3
Rates of Energy Consumption
Product type Annual Usage,
kWh*
Annual
cost**
Unillumintated Static Sign 0 $0
Noventri "green" player 35 $4.80
Noventri PC based player 1,752 $240
Corn Digital 42" LCD Display 2,103 $288
Hewlett‐Packard 47" LCD Display 2,737 $375
Salescaster Corp. 76"x12" LED sign (8‐color) 4,380 $600
Static Billboard (4) Halide Lamps ‐ calculated 7,008 $960
LED Authority 36"x60" LED sign (full color) 8,760 $1,200
Average US home 11,040 $1,512
LED Billboard (L.A. Reading) 61,032 $8,361
Barco LED 73,584 $10,081
Lighthouse LVP2056 92,715 $12,792
AGX digital 14' x 48 ' billboard 117,866 $16,148
14' x 48' LED Billboard (Florida actual reading) 162,902 $22,318
EraLED Series P20 Billboard 249,690 $34,208
ThinkSign LED 248,993 $34,112
Optec Displays LED 323,773 $44,357
* Energy Usage (((24))((365))/1000
** Average costs per kWh=$.137 (Metro Area)
4
In many applications---such as television/computer display, general lighting, and small
electronics---LCD, plasma screen, and LED technological advancements have proven
more energy efficient than their predecessors, but research indicates that out-of-home
advertising is simply not an appropriate or responsible application for digital technology.
5
Sign Brightness
Measuring Sign Brightness
Apart from energy consumption, there are the
important issues of light trespass and light
pollution, which cause distraction, obscure stars
in the night sky, and, like any other form
of pollution, disrupt ecosystems and cause
adverse health effects for humans and wildlife
alike. Light trespass 5 is measured in two ways:
luminance or illuminance. Luminance
(measured in nits 6 ) quantifies surface
brightness, or the amount of light an object
gives off. Illuminance (measured in
footcandles 7 ) quantifies that amount of light
which falls onto an object.
This sign (above) gives off light.
Its Luminance is measured in nits.
By either measure, digital signage can create
significant problems. “During daylight, an unlit
static billboard will have a brightness which
“fits in” with its surroundings; it will not cause
excessive distraction because of excessive
luminance” (Carhart, 2010, p.4). But, to capture
drivers’ attention, digital signs must be set to
very high luminance levels, as they are
essentially competing with the sun, which has a
luminance level of 6,500 nits. If this extreme
brightness is not modulated to fit nighttime
conditions, we face issues including very high
energy consumption during the day, light
pollution in the evening, and potential driver
distraction at all times. The OAAA (Outdoor
Advertising Association of America) has
guidelines to address brightness limits, but they
are not mandated.
This sign (above) is being lit by a light source.
Its Illuminance is measured in footcandles.
5 Light trespass occurs when unwanted light enters one's property, for instance, by shining over a neighbor's fence. A
common light trespass problem occurs when a strong light enters the window of one's home from the outside
6 Nit—term used to describe a metric unit of luminance. It it is defined as candela per square meter (cd/m2). The unit
is based on the candela, the modern metric unit of luminous intensity; and the square meter.
7 Footcandle – Unit of light density incident on a plane (assumed to be horizontal unless otherwise specified), and
measurable with an illuminance meter, a.k.a. light meter.
6
Limiting Sign Brightness
Proposed limits on sign brightness have caused much debate. Research provided by the
Illuminating Engineering Society of North America (IESNA) states that drivers should be
subjected to points of brightness no greater than 40 times the average brightness level of
their general surroundings; this proportion is known as the contrast ratio. “As roadway
lighting and automobile headlights provide ambient nighttime lighting levels of about one
nit, this implies signage should appear no brighter than about 40 nits” (Luginbuhl, 2010,
p.1). Surprisingly, the IESNA’s own recommendations for signage luminance suggest
limits between 250-1400 nits---greatly exceeding their stated maximum contrast ratio of
40:1.
The OAAA, has deemed 300-350 nits an acceptable level of night brightness. However,
their guidance is based on the use of the IEEE standard for light trespass (IESNA-TM-11-
00), when, for reasons of traffic safety and glare in drivers’ eyes, it should have been
based on IEEE’s standard for roadway sign lighting (IESNA RP-19-01).
Traditionally floodlit static billboards rarely exceed 100 nits; experts on both driver
distraction and light pollution recommended that, as a means of compromise, the new
technologies should not exceed this value. In many areas, including Philadelphia,
brightness levels are currently unregulated, and many manufacturers publicize their
signs’ capabilities to reach up to 11,000 nits.
7
Digital signage advocates mention the horizontal louvers 8 included in many billboards as
an effective measure to prevent light pollution. In reality, these louver systems were
designed primarily to shade each diode from sunlight (thus increasing their prominence),
not to limit nighttime glow.9 As Luginbuhl states in "Lighting and Astronomy,"
horizontal light (that which is emitted between 0° and roughly ±20°, and not restricted by
horizontal louvers) contributes even more to skyglow than light emitted at higher angles.
The effects of lower-angle lighting----such as that used to captivate approaching drivers--
- are visible over a much broader area (Carhart, 2010).
A better option is to simply operate signs at less than maximum brightness. Not
surprisingly, sign brightness and energy usage are directly related; beyond reducing light
pollution and distraction, lowering luminance reduces total power consumption. One
manufacturer experimented with running their digital displays at half-brightness; they
were able to reduce power usage by nearly 40%, while maintaining full sign readability
(Noventri, see in chart). Another option for reducing unnecessary brightness (and thus
power usage) is to equip signs with sensors which automatically lower light output in
accordance with atmospheric conditions. For example, sign brightness would
mechanically be dimmed during dusk, early morning hours, or during cloudy or overcast
weather. Again, OAAA does have guidelines for dimming, but they are not mandatory.
8 A louver is a slat that is angled to keep out rain, direct sunshine, etc. The angle of the slats may be
adjustable or fixed.
9Retrieved from http://www.optec.com
8
Materiality and Recyclability
Life Span
Light Emitting Diodes have a lifespan of 100,000 hours. According to Bryant, this
equates to roughly eleven years for LED billboards, compared to the fifteen years for
traditional static billboards. At that point, the diodes will be operating at 50% of their
prime brightness. Of course, considering the return on investment that the sign owner has
received by that time, he or she will likely not hesitate to replace the sign quickly
(Bryant, 2008). As these large digital displays and their associated digital players
increase in popularity, will we soon face an abundance of difficult to recycle, discarded
technology?
Techno-Waste
Obsolete technology is a valuable source for secondary raw materials, if treated properly;
if not treated properly, it can be a source of toxins and carcinogens. Rapid industrial
advancement, decreasing initial cost, and even planned obsolescence could result in a
fast-growing surplus of “techno-waste” (Morgan, 2006). LED’s, plasma and LCD
screens, and digital players and extenders are recyclable, but their de-manufacturing and
reuse is not always mandated or monitored.
In the US, the main federal law governing solid waste is the Resource Conservation and
Recovery Act of 1976; as far as electronics are concerned, it covers only cathode ray
tubes (televisions and computer monitors popular before LCDs, plasma and LEDs),
though state regulations may differ, according to the U.S. Environmental Protection
Agency. Volumetrically, digital signage does generate more waste to be recycled than
the paper, vinyl sheets, and plywood or canvas facing of static billboards, but lacks the
potentially toxic adhesives.
Technological Graveyard: A massive collection of now-obsolete Cathode Ray Tube
televisions. Could digital signage one day face a similar fate?
9
Future Technological Innovation
Digital display types have become increasingly energy efficient since their inception, a
trend that will likely continue. While early generations of LED lamps could produce
only 20 lumens per watt (compared to about 15 lumens/watt for incandescent), current
models can achieve over 100 lumens/watt (Klipstein, 2009). More energy efficient
players are also in development, including a model that uses only 4 watts of electricity,
the equivalent of a single small light bulb. As technology continues to progress, there is
hope that digital signage may one day be a truly green option, but we are not there today.
Solar Power
Solar power is one promising advancement recently used in the installation of a 6,000 sq.
ft. digital billboard in Times Square which is fully powered by solar panels and
photovoltaic solar modules, and illuminated by floodlights. It consumes no additional
electricity. According to Cooley’s Commercial Graphics, manufacturer of the solar sign,
“These lightweight systems could be installed on some portion of the 450,000 billboards
currently in the United States. Each of these billboards would generate clean renewable
energy to either power the billboard lighting system or would be sold back to local utility
companies through net metering or feed in tariffs programs” (Connor 2010).
A similar program has been implemented in San Francisco, and successfully generates up
to 3.4 kilowatts of excess energy, distributed to local utility customers.10 Some are
skeptical, however; an industry insider states, “illuminating signage via solar power poses
a significant hurdle, because harvesting and processing solar energy is relatively
inefficient,” and estimates that approximately only 20% of energy collected could be
retransmitted as sign illumination (Aust, 2007). While these green advancements are
laudable, they are climate-dependent, and their high initial costs make them unlikely for
mainstream usage without government mandates or incentives.
Average 2008 Air Travel
(Total US Commercial air
travel for 2008 / Census
Estimate of total US
population)
Average 2008
travel by
passenger car:
calculated for
small car
Average 2008
travel by
passenger car:
calculated for
SUV Average Home
Digital
Billboard
(L.A.
Reading)
Optec
Displays
LED
Total annual emissions (tons)0.93 2.48 6.59 8.28 45.77 242.82
No. of trees to offset per year 4.66 12.38 32.96 41.4 228.87 1,214.10
Carbon Footprint
10 (2007, December 3). Retrieved from http://www.environmentalleader.com/2007/12/03/pges-green-campaign-gets-
solar-powered-billboard/
10
Economic Feasibility and
Return on Investment
Off-Premise, Non-Accessory Billboards
In addition to their environmental impacts, we looked into
the profitability of digital billboards, and received mixed
results. Although LEDs are expensive, manufacturers
frequently claim that cost is recouped over time and in reduced energy usage and
maintenance costs. For off-premise advertising, the initial investment in a digital sign is
large---$250,000-$500,000 (Goldstein, 2008)---but future overhead for the advertising
company is low, as graphics can be remotely changed and replaced. Often, they are also
able to rent out the advertising space for a higher premium than on static billboards.
Space on a digital billboard rents at the same rate, or higher, as a comparably sized static
billboard, even though each ad will be featured only intermittently, sharing space with up
to eight other advertisements in the rotating lineup. This means huge profit increases for
the outdoor advertising companies, and a quick return on investment. Digital
billboards provide operators with an average of $14,000 per month in rent (typically
from multiple advertisers), compared with $1,000 to $2,000 per month for
traditional billboards, which serve only one advertiser (Goldstein, 2008).11 Total
revenue from the outdoor digital signage equipment market in the United States,
including hardware, software, installation, and maintenance, grew by about 33% in 2009,
a trend that is expected to continue. The Federal Highway Administration estimates that
in 1996 there were over 400,000 billboards on federally controlled roads, which
generated revenues in excess of $1.96 billion (Schueller, n.d.).
On-Premise, Accessory Signs
On-premise advertising appears to be less cost-effective. The initial cost of installing a
digital signage network has not been recouped by many of the operators interviewed, to
say nothing of the dramatic increase in energy expenditures when compared to static
signage (Noventri, 2010). Additionally, the burden of providing frequently-changing
content falls on the operator; many small businesses simply do not have the creative staff
or technical knowledge to create changeable graphic displays.
Despite uncertain profitability for on-premise signs, market statistics and lay observation
point to the growing popularity of digital signage, both off-premise and on-premise. In
the absence of guaranteed profits, their chief selling point is their uniqueness---the fact
that they “stand out.” However, as this type of advertising becomes more mainstream,
and the market becomes saturated, how long can simple novelty justify its high financial
and environmental costs?
11 Sales prices reflect market averages in Bangor, PA. Rates may vary with location.
11
Current Trends
How big of a problem do unregulated energy consumption and luminance levels pose?
Right now, only a small fraction of American outdoor advertising is digital. This number
is growing, however, and the trend shows no sign of slowing. Rapidly-dropping prices
for large LED screens have led to a growing increase in the number of digital signage
installations. Today, there are nearly 800 of these digital billboards in the U.S. It's a
small number compared with 450,000 traditional billboards across the country, but it's
growing fast. The Outdoor Advertising Association of America, an industry trade group,
projects that the number of digital billboards in the U.S. will expand at a rate of several
hundred per year (Goldstein, 2008). Clear Channel Outdoor Holdings, an industry
powerhouse, says it is expanding its digital billboard business in markets such as Los
Angeles, Chicago and Philadelphia (Hau, 2007). Philadelphia is home to an estimated
1,800 billboards, including a handful of digital signs---the effects of widespread
conversion from static to digital would raise significant safety and environmental issues.
Rapid Growth: The number of digital billboards is increasing at an increasing rate in the US,
as evidenced by the above graph. On-premise digital signage has shown an even more
dramatic increase in popularity (Urazbaev, 2009).
12
How Does Philadelphia’s Current Zoning Code
Regulate Electronic Signage?
Simply put, it doesn’t address the
technology. Signage regulation within the
Philadelphia zoning code (Section 14-
1604) was passed in the early 1990s and
does not specifically address electronic
outdoor advertising. The code for on-
premise signage (storefront signage) is
equally devoid of controls on electronic
signage, opening an opportunity for these
kinds of signs in all commercial districts.
A leader in the outdoor advertising
industry, Clear Channel, has embraced the
digital trend. The company has revamped
several of its existing static billboards to
LED format along the I-95 corridor in
Philadelphia. In order to proceed with the
conversions, Clear Channel sought the
approval of Philadelphia’s Department of
Licenses and Inspections (L&I), which
granted permission for the conversions to
take place with few requirements. This
interpretation was made in spite of clear
language in the code prohibiting an outdoor
advertising sign from carrying more than
two messages at one location. Under
L&I’s current interpretation of the code,
any billboard that is 500 feet or more away
from residentially zoned property may be
converted to electronic as of right. If this
interpretation remains in place, this could
translate to hundreds of converted
electronic billboards – the only factor
moderating conversions right now is the
(continually decreasing) expense involved.
Pink dots denote Philadelphia’s current
inventory of digital billboards (10 total),
concentrated along I-95 and the
Schuykill Expressway
13
Examples from Other Cities
To date, no known city has passed limits on sign energy usage, but about one quarter of
states in the U.S. prohibits moving or animated signs, and roughly one third have
specifications for dwell time ranging from four seconds to several minutes. Most states
prohibit flashing red lights and anything that causes a glare or vision impairment.
Pittsburgh, Pennsylvania
A proposed amendment to Pittsburgh’s zoning code states that no electronic sign may
exceed .3 foot candles illumination above ambient light level to prevent distraction and
interference with traffic signals. As discussed earlier in this paper, OAAA recommends
foot candles in its guidelines but the usefulness of this measurement has been questioned
and nits is the preferred measurement for detecting brightness and glare emitted from
digital signs). Additionally, Pittsburgh’s amendment sets a dwell time of at least ten
seconds, and prohibits animation of any kind.12
Concord, New Hampshire
Some cities and states have banned electronic message boards outright, including
Concord, New Hampshire. There, the ban on electronic message centers was upheld on
appeal to the First Circuit Court, on grounds that the ban promoted both traffic safety and
community aesthetics (Carpentier, 2009). 13
Panama City Beach, Florida
In the absence of a cohesive state or federal policy, residents and policy makers in
Panama City Beach, Florida decided they could not allow digital signage to continue to
proliferate unfettered. They drafted a set of restrictions on sign size, placement and
brightness which have been incorporated into the City Code. “The specifications make
regulation seem like an exact science, when it's really just public and private actors
negotiating acceptable limits,” voices one critic. While imperfect, it sets a valuable
precedent for regulation because the proposed ordinance limits the amount of light digital
signs can emit, their illumination must be measured and monitored by an instrument
widely available and specially designed for this purpose.
Tulsa, Oklahoma
The study "Digital Billboard Recommendations and Comparisons to Conventional
Billboards" recommends billboard brightness of 342 nits for an average sized (10’6” x
36’) billboard under average ambient lighting conditions (Lewin, 2008).14 In response to
these recommendations, the Planning Commission of Tulsa, Oklahoma recommended a
limit of 300 nits for all signage, but this was raised to 500 nits before becoming law, due
to pressure from the outdoor advertising industry.
12 The Pittsburgh Code, Title Nine, Zoning Code, Article VI, Chapter 919, Signs.
13 Naser Jewelers, Inc. v. City of Concord, 2008. WL 162521 (C.A. 1 N.H. 1/18/2008)
14 n.b. This study was funded by the Outdoor Advertising Association of America.
14
Municipalities that ban or limit digital billboards
STATE CITY/COUNTY ACTION TAKEN
Alaska (state) Ban
Arizona Gilbert Ban
Arizona Pima County Moratorium
California Los Angeles Moratorium
California San Francisco Ban
Colorado Denver Ban
Florida Largo Ban
Florida Pinellas County Moratorium
Florida St. Petersburg Ban
Georgia Atlanta Moratorium
Hawaii (state) Ban
Maine (state) Ban
Michigan (state) Considering Moratorium
Minnesota Minnetonka Moratorium
Minnesota Oakdale Moratorium
Minnesota (state) Considering Moratorium
Missouri Lake St. Louis Ban
Missouri St. Louis Moratorium
Montana (state) Ban
North Carolina Durham Ban
Rhode Island (state) Moratorium
Tennessee Knoxville Ban
Texas Amarillo Ban
Texas Austin Ban
Texas Dallas Ban
Texas El Paso Moratorium
Texas Ft. Worth Ban
Texas Galveston Ban
Texas Houston Ban
Texas San Antonio Moratorium
Vermont (state) Ban
15
Policy Recommendations:
Electronic Signage and Philadelphia’s Future
Philadelphia is currently in the
process of a complete overhaul
of its zoning code and
comprehensive plan, bringing
the city into the present and
preparing for its future. A
recently released draft of the
updated code does aim to
control digital advertising, but
more (and better) regulation is
needed; the draft focuses on
off-premise advertising, and is
particularly relaxed regarding
on-premise electronic message
boards.
For the purposes of controlling light pollution and energy consumption, the distinction
between on-premise and off-premise signage is of little relevance; as such, we offer
similarly cautionary restrictions for both sign types, from a traffic safety perspective, on–
premise signs may be worse. They can be bigger, closer to the roadway, have motion and
animation (Wachtel, 2009).
Our first issue with the draft is one of semantics: currently, the draft specifically regulates
any sign with action or motion, animation, rotation, scrolling, flashing or color changes,
or upon which illumination is not maintained at a constant stationary intensity and/or
color, as a means (we assume) of regulating digital signage in general. We anticipate that
this language could create the opportunity for misinterpretation; electronic and digital
message boards are not necessarily flashing/animated/intermittent, as they are capable of
the display of static, yet still excessively bright, imagery. Advertising companies often
specifically describe their digital signage as “static,” as a way to circumvent inexplicit
regulation such as this.
We suggest revising the zoning language to include any and all digital signage, defined as
any sign capable of displaying words, symbols, figures or images that can be
electronically or mechanically changed by remote or automatic means,15 not just those
that are animated, flashing, or intermittent, which can be subjective descriptions.
15 From Oklahoma City Municipal Code, 2007, Chapter 3, Article V, Section 3-82.
16
The current draft states that off-premise digital
billboards are not to be located within 500 feet of
an entrance or exit ramp to any major highway, or
within 200 feet of any intersection of the street or
highway on which it is intended to advertise to.
For off-premise signage, the proposed code
prohibits flashing signs, signs with intermittent
illumination, or signs with mechanically or
electronically changing messages within 500 ft. of
any residential district. It also prohibits them from
facing any residential district within 1,000 ft. For
on-premise digital signage, these distances are
lowered to 150 ft. and 300 ft., respectively.
We recommend that this regulation be expanded
and increased; best practices from the Australian
states of Queensland, Victoria and New South Wales, South Africa and The Netherlands
illustrate the rigor with which the situation of electronic advertising must be assessed
before it can be deemed safe for motorists and other road users. Among the
considerations these governments require in assessment of the placement of outdoor
advertising are: traffic speed on the adjacent roadway, sign content, legend height,
vicinity of official traffic control devices, type of street or interchange, sign brightness,
hold time, sign content, the potential that an advertisement will be mistaken for a traffic
control device, the amount of information communicated, the concision and legibility of
the advertising message, and an advertising structure’s obstruction of key sightlines.
These best practices are detailed in the attached Appendix D, Excerpt from 2009
AASHTO Report. (Wachtel)
According to the present draft, signs may be illuminated, but the illumination shall be
focused upon the sign itself, so as to prevent glare upon the surrounding areas, and digital
billboards must have a luminance level appropriate to the ambient environment in
keeping with the standards set forth by the Illuminating Engineering Society of North
America (IESNA). These regulations are too vague; we propose specific limits to
prevent light trespass and light pollution. As such, the illumination projected from any
use shall at no time exceed 0.1 footcandle onto a residential use, and 1.0 footcandle onto
a non-residential use. This should apply to light emitted from any form of signage, on-
premise or off-premise. We also propose specific luminance limits of 100 nits for
nighttime conditions, applicable to all digital signage. (Lebenbuhl)
16th & Washington, Philadelphia
On-premise LED sign
17
Additionally, there must be prescribed methods for determining compliance with the
aforementioned illuminance and luminance limits. Again, illuminance measures the
amount of light which falls onto an object; luminance measures the amount of light an
object gives off. To gauge light trespass on neighboring properties, illumination shall
be measured (in footcandles) at any time and from any point on the receiving property
line using an illuminance light meter. While an illuminance meter is a practical device
with which to measure light trespass, inherent sign brightness is best measured using a
luminance meter, which is capable of directly measuring the surface brightness of signs.
Luminance meters are quite costly; sign owners should be financially responsible, by
means of permit fees, for any and all equipment/operational costs needed to ensure that
their luminance levels remain in compliance with aforementioned limits.
Luminance limits between the full sunlight limit and the nighttime limit may also be
specified for overcast or foggy days. Regulations should require an automated control of
sign luminance based on current ambient lighting conditions. To further control light
pollution, off-premises digital signs shall be extinguished automatically no later than
11:00pm each evening until dawn. Signs for establishments that operate or remain open
past 11:00 p.m. may remain on no later than one half hour past the close of the
establishment.
Where new digital signage construction or digital conversions are permitted, there should
be a “trade-off” policy, based on power consumption. For every square footage of digital
signage an outdoor advertising company installs, via new construction or conversion,
they must remove a specified amount of square footage of their existing static signage, in
order to maintain or reduce their carbon footprint. Such a policy has been implemented
in many cities and states. Finally, obsolete or otherwise discarded digital signage, and all
accessory components, must be fully recycled at the expense of the manufacturer.
Conclusion
Our research and the resultant policy recommendations could not come at a better time,
as digital signage figures prominently on several hot-button issues regarding Philadelphia
urban development. For example, the Market East corridor of Philadelphia is in great
need of renewal and rethinking; the look and feel of the “new” Market East is a very
controversial topic. Councilman Frank DiCicco's Outdoor Advertising Bill 100013 takes
away the city's ability to regulate signage and will allow massive outdoor advertising
signs including LED digitals and rooftop billboards along Market Street between 7th and
13th Streets, transforming Market East into a garish thoroughfare reminiscent of the Las
Vegas Strip.
Paul Levy, president and CEO of the Center City District and a key player in the
revitalization of Market East, is amenable to the sorts of eye-catching wraps, digital and
LED signs, though he says the city must make sure they stimulate development.
18
“Building owners shouldn't get to throw up a giant ad on a tiny decrepit storefront. They
should only be able to profit from these signs --- and thus generate tax revenue for the
city --- if they renovate their properties in line with city standards and fill them with
people” (Rubin 2010).
Over the past ten years, many studies of digital signage have focused on the issue of
driver distraction and road safety. These studies have been conducted in many countries
(e.g. U.S., U.K., Australia, South Africa, The Netherlands, Norway, and others) and they
have used a variety of research methods, including simulator and laboratory
investigations, opinion surveys and focus groups, on-road studies in instrumented
vehicles, and longitudinal analysis of summaries of traffic collision reports. With only
two exceptions, those recent studies performed by government agencies, universities, and
non-profit traffic safety organizations, have found a detrimental effect on driver
distraction (or other measures of traffic safety) in the presence of billboards. The only
studies that have reported no adverse safety impact of digital billboards have been those
sponsored by the outdoor advertising industry.
And we use the word "reported" advisedly. That is because, in one case, despite the study
authors reporting no distraction from digital billboards, the actual data collected clearly
showed such an adverse impact. And, in the other case, despite the study authors
reporting that the presence of digital billboards had no effect on traffic crashes, the
authors have been challenged by experts, both in peer review and in public forums, for
using improper statistical methods - with the results that their reported conclusions are
unjustified and should be retracted.
The Federal Highway Administration is nearing completion of its own on-road research
study looking at levels of driver distraction as measured by eye movements in the
presence and absence of digital billboards. This report is expected to be available in the
first quarter of 2011.
Higher electricity consumption, increased light pollution, and recyclability issues should
make us pause and question the growing popularity of digital signage. As America at last
embraces sustainability and Philadelphia strives to become the “greenest city in
America,” is a proliferation of digital signs along our highways and storefronts sending
the right message?
19
About the Author:
Gregory Young, LEED AP is an architectural designer and urban planner active in
Philadelphia, Pennsylvania. A recent graduate of the University of Pennsylvania (School
of Design), his research was generously supported by a grant from the Samuel F. Fels
Fund. Policy recommendations were made in collaboration with SCRUB: Public Voice
for Public Space. SCRUB is a Philadelphia-based non-profit, founded in 1990 with the
mission to promote healthy, vibrant and beautiful public spaces throughout all of
Philadelphia using advocacy, public awareness, community mobilization and legal action.
Visit http://www.publicvoiceforpublicspace.org/ for more information.
20
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22