scholarly journals Impact of Dim Light at Night on Urinary 6-Sulphatoxymelatonin Concentrations and Sleep in Healthy Humans

2020 ◽  
Vol 21 (20) ◽  
pp. 7736
Author(s):  
Katarina Stebelova ◽  
Jan Roska ◽  
Michal Zeman
Keyword(s):  
Sleep Quality ◽  
Real Life ◽  
Artificial Light ◽  
Health It ◽  
Negative Effects ◽  
Light At Night ◽  
Healthy Humans ◽  
Home Based ◽  
Fragmentation Index ◽  
Melatonin Production

Artificial light at night can have negative effects on human wellbeing and health. It can disrupt circadian rhythms, interfere with sleep, and participate in the progress of civilisation diseases. The aim of the present study was to explore if dim artificial light during the entire night (ALAN) can affect melatonin production and sleep quality in young volunteers. We performed two experiments in real-life home-based conditions. Young volunteers (n = 33) were exposed to four nights of one lux ALAN or two nights of five lux ALAN. Melatonin production, based on 6-sulphatoxymelatonin/creatinine concentrations in urine, and sleep quality, based on actimetry, were evaluated. Exposure to ALAN one lux during the entire night did not suppress aMT6s/creatinine concentrations but did aggravate sleep quality by increasing sleep fragmentation and one-minute immobility. ALAN up to five lux reduced melatonin biosynthesis significantly and interfered with sleep quality, as evidenced by an increased percentage of one-minute immobility and a tendency of increased fragmentation index. Our results show that people are more sensitive to low illuminance during the entire night, as previously expected. ALAN can interfere with melatonin production and sleep quality in young, healthy individuals, and both processes have different sensitivities to light.

scholarly journals Mapping the Melatonin Suppression, Star Light and Induced Photosynthesis Indices with the LANcube

2020 ◽  
Vol 12 (23) ◽  
pp. 3954
Author(s):  
Martin Aubé ◽  
Charles Marseille ◽  
Amar Farkouh ◽  
Adam Dufour ◽  
Alexandre Simoneau ◽  
...  
Keyword(s):  
Artificial Light ◽  
Spectral Indices ◽  
Light At Night ◽  
Spectral Content ◽  
Melatonin Suppression ◽  
High Resolution Mapping ◽  
Resolution Mapping ◽  
Index 2 ◽  
Negative Impacts ◽  
Melatonin Production

Increased exposure to artificial light at night can affect human health including disruption of melatonin production and circadian rhythms which can extend to increased risks of hormonal cancers and other serious diseases. In addition, multiple negative impacts on fauna and flora are well documented, and it is a matter of fact that artificial light at night is a nuisance for ground-based astronomy. These impacts are frequently linked to the colour of the light or more specifically to its spectral content. Artificial light at night is often mapped by using spaceborne sensors, but most of them are panchromatic and thus insensitive to the colour. In this paper, we suggest a method that allows high-resolution mapping of the artificial light at night by using ground-based measurements with the LANcube system. The newly developed device separates the light detected in four bands (Red, Green, Blue and Clear) and provides this information for six faces of a cube. We found relationships between the LANcube’s colour ratios and (1) the Melatonin Suppression Index, (2) the StarLight Index and (3) the Induced Photosynthesis Index. We show how such relationships combined with data acquisition from a LANcube positioned on the top of a car can be used to produce spectral indices maps of a whole city in a few hours.

scholarly journals The preference and costs of sleeping under light at night in forest and urban great tits

2019 ◽  
Vol 286 (1905) ◽  
pp. 20190872 ◽  
Author(s):  
Zeynep N. Ulgezen ◽  
Teemu Käpylä ◽  
Peter Meerlo ◽  
Kamiel Spoelstra ◽  
Marcel E. Visser ◽  
...  
Keyword(s):  
Oxalic Acid ◽  
White Light ◽  
Cognitive Abilities ◽  
Daily Activity ◽  
Activity Patterns ◽  
Spectral Composition ◽  
Green Light ◽  
Artificial Light ◽  
Negative Effects ◽  
Light At Night

Artificial light at night (ALAN) is an increasing phenomenon associated with worldwide urbanization. In birds, broad-spectrum white ALAN can have disruptive effects on activity patterns, metabolism, stress response and immune function. There has been growing research on whether the use of alternative light spectra can reduce these negative effects, but surprisingly, there has been no study to determine which light spectrum birds prefer. To test such a preference, we gave urban and forest great tits (Parus major) the choice where to roost using pairwise combinations of darkness, white light or green dim light at night (1.5 lux). Birds preferred to sleep under artificial light instead of darkness, and green was preferred over white light. In a subsequent experiment, we investigated the consequence of sleeping under a particular light condition, and measured birds' daily activity levels, daily energy expenditure (DEE), oxalic acid as a biomarker for sleep debt and cognitive abilities. White light affected activity patterns more than green light. Moreover, there was an origin-dependent response to spectral composition: in urban birds, the total daily activity and night activity did not differ between white and green light, while forest birds were more active under white than green light. We also found that individuals who slept under white and green light had higher DEE. However, there were no differences in oxalic acid levels or cognitive abilities between light treatments. Thus, we argue that in naive birds that had never encountered light at night, white light might disrupt circadian rhythms more than green light. However, it is possible that the negative effects of ALAN on sleep and cognition might be observed only under intensities higher than 1.5 lux. These results suggest that reducing the intensity of light pollution as well as tuning the spectrum towards long wavelengths may considerably reduce its impact.

scholarly journals The duration of artificial light defines sexual signalling in the common glow-worm

2021 ◽  
Vol 75 (11) ◽  
Author(s):  
Christina Elgert ◽  
Topi K. Lehtonen ◽  
Arja Kaitala ◽  
Ulrika Candolin
Keyword(s):  
Negative Impact ◽  
Light Exposure ◽  
Sensory Ecology ◽  
Mitigation Measures ◽  
Light Pollution ◽  
Artificial Light ◽  
Negative Effects ◽  
Light At Night ◽  
Night Time ◽  
Sexual Signalling

Abstract Artificial light at night is increasing globally, interfering with both sensory ecology and temporal rhythms of organisms, from zooplankton to mammals. This interference can change the behaviour of the affected organisms, and hence compromise the viability of their populations. Limiting the use of artificial light may mitigate these negative effects. Accordingly, we investigated whether the duration of artificial light affects sexual signalling in female glow-worms, Lampyris noctiluca, which are flightless and attract flying males to mate by emitting glow that is interfered by light pollution. The study included three treatments: no artificial light (control), 15 min of artificial light, and 45 min of artificial light. The results show that females were more likely to cease glowing when the exposure to light was longer. Furthermore, small females were more likely to cease their glow, and responded faster to the light, than larger females. These findings suggest that glow-worms can react rapidly to anthropogenic changes in nocturnal light levels, and that prolonged periods of artificial light trigger females to stop sexual signalling. Thus, limiting the duration of artificial light can mitigate the adverse effects of light pollution on sexual signalling, highlighting the importance of such mitigation measures. Significance statement Interest in the effects of artificial light at night on animal behaviour has increased in recent years. With evidence for its negative impact accumulating, potential remedies, such as limiting the duration of light exposure, have emerged. To date, however, knowledge on the effectiveness of these methods has remained very limited. We show that female European common glow-worms, which are wingless beetles that glow to attract flying males to mate, responded to prolonged artificial light exposure by discontinuing their glow. Such non-glowing females are not expected to find a mate, making it difficult for them to reproduce. Hence, our study indicates that the duration of artificial light should be limited to protect this night-active beetle and its opportunities for effective sexual signalling. Because many other nocturnal species also need darkness, this study provides valuable information for the development and use of less disruptive night-time lights.

scholarly journals Mapping the Melatonin Suppression, Star Light and Induced Photosynthesis Indices with the LANcube

2020 ◽  
Author(s):  
Martin Aubé ◽  
Charles Marseille ◽  
Ammar Farkouh ◽  
Adam Dufour ◽  
Alexandre Simoneau ◽  
...  
Keyword(s):  
Artificial Light ◽  
Spectral Indices ◽  
Light At Night ◽  
Spectral Content ◽  
Melatonin Suppression ◽  
High Resolution Mapping ◽  
Resolution Mapping ◽  
Index 2 ◽  
Negative Impacts ◽  
Melatonin Production

Increased exposure to artificial light at night can affect human health including disruption of melatonin production and circadian rhythms and extend to increased risks of hormonal cancers and other serious diseases. In addition, multiple negative impacts on fauna and flora are well documented, and it is a matter of fact that artificial light at night is a nuisance for ground-based astronomy. These impacts are frequently linked to the colour of the light or more specifically to its spectral content. Artificial light at night is often mapped by using space borne sensors, but most of them are panchromatic and thus insensitive to the colour. In this paper, we suggest a method that allows high resolution mapping of the Artificial light at night by using ground-based measurements with the LANcube system. The device separates the light detected in four bands (Red, Green, Blue, and Clear) and provides this information for six faces of a cube. We found relationships between the LANcube’s colour ratios and 1- the Melatonin Suppression Index, 2- the StarLight Index and 3- the Induced Photosynthesis Index. We show how such relationships combined with data acquisition from a LANcube positioned on the top of a car can be used to produce spectral indices maps of a whole city in a few hours.

scholarly journals 0383 Outdoor Artificial Light at Night, Sleep Duration, and Sleep Quality in the California Teachers Study Cohort

SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A147-A147
Author(s):  
C Zhong ◽  
M Franklin ◽  
J Wiemels ◽  
N Chung ◽  
J Benbow ◽  
...  
Keyword(s):  
Sleep Quality ◽  
Sleep Time ◽  
National Institutes Of Health ◽  
Study Cohort ◽  
Poor Sleep ◽  
Artificial Light ◽  
Sleep Habits ◽  
Light At Night ◽  
Circadian Patterns

Abstract Introduction Artificial light at night (ALAN) is believed to disrupt sleep by suppressing melatonin and altering normal circadian patterns. We assessed the association between self-reported sleep measures and outdoor ALAN in a large cohort of women. Methods The California Teachers Study (CTS) is a prospective cohort of 133,479 current and former Californian female public school professionals recruited and given a baseline questionnaire in 1995-1996. A follow-up questionnaire in 2012-2014 assessed self-reported measures of sleep habits, quality, and chronotype. Using geocoded residential addresses, participants were assigned exposures to outdoor ALAN based on the New World Atlas of Artificial Night Sky Brightness to assess the association between ALAN and self-reported sleep initiation, duration, and quality. Results Of the 42,706 women who completed the follow-up questionnaire and reported the same sleep patterns over the previous year, 5,968 reported poor sleep quality. The median outdoor ALAN was 2.16 (IQR: 1.04-3.61) millicandela per meter squared (mcd/m2). After adjusting for self-reported chronotype, use of sleep medication, age, race, and socioeconomic status, residing in the highest ALAN quintile was associated with poor sleep (OR 1.16, 95% CI 1.07-1.26). There did not appear to be an association between outdoor ALAN and time taken to fall asleep (OR 1.02, 95% CI 0.96-1.08), but it was associated with sleeping less than 8 hours (OR 1.41, 95% CI 1.33-1.50). Conclusion CTS participants who self-reported shorter sleep and poorer sleep quality were more likely to reside in areas with greater levels of outdoor ALAN. We did not see an association with ALAN and time to fall asleep, suggesting ALAN may be contributing to later sleep time or earlier waking. As we continue to follow this cohort, the data collected over the past 20 years provide a rich resource for studying both factors related to sleep and its effect on health. Support The California Teachers Study and the research reported in this publication were supported by the National Cancer Institute of the National Institutes of Health under award number U01-CA199277; P30-CA033572; P30-CA023100; UM1-CA164917; R01-CA077398; and R01-CA207020.

scholarly journals Lighting Professionals versus Light Pollution Experts? Investigating Views on an Emerging Environmental Concern

2019 ◽  
Vol 11 (6) ◽  
pp. 1696 ◽  
Author(s):  
Nona Schulte-Römer ◽  
Josiane Meier ◽  
Etta Dannemann ◽  
Max Söding
Keyword(s):  
Environmental Concern ◽  
Lighting Design ◽  
Problem Definition ◽  
Light Pollution ◽  
Artificial Light ◽  
Negative Effects ◽  
Light At Night ◽  
Lighting Industry ◽  
Governance Challenges ◽  
Conflicting Interests

Concerns about the potential negative effects of artificial light at night on humans, flora and fauna, were originally raised by astronomers and environmentalists. Yet, we observe a growing interest in what is called light pollution among the general public and in the lighting field. Although lighting professionals are often critical of calling light ‘pollution’, they increasingly acknowledge the problem and are beginning to act accordingly. Are those who illuminate joining forces with those who take a critical stance towards artificial light at night? We explore this question in more detail based on the results of a non-representative worldwide expert survey. In our analysis, we distinguish between “lighting professionals” with occupational backgrounds linked to lighting design and the lighting industry, and “light pollution experts” with mostly astronomy- and environment-related professional backgrounds, and explore their opposing and shared views vis-à-vis issues of light pollution. Our analysis reveals that despite seemingly conflicting interests, lighting professionals and light pollution experts largely agree on the problem definition and problem-solving approaches. However, we see diverging views regarding potential obstacles to light pollution mitigation and associated governance challenges.

scholarly journals Artificial Light at Night Reduces Anxiety-Like Behavior in Female Mice with Exacerbated Mammary Tumor Growth

Cancers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 4860
Author(s):  
William H. Walker ◽  
Raegan M. Kvadas ◽  
Laura E. May ◽  
Jennifer A. Liu ◽  
Jacob R. Bumgarner ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Mammary Tumor ◽  
Anxiolytic Effect ◽  
Sucrose Preference ◽  
Artificial Light ◽  
Negative Effects ◽  
Light At Night ◽  
Tumor Bearing ◽  
Tumor Onset ◽  
Mammary Tumor Growth

Artificial light at night (ALAN) is a pervasive phenomenon. Although initially assumed to be innocuous, recent research has demonstrated its deleterious effects on physiology and behavior. Exposure to ALAN is associated with disruptions to sleep/wake cycles, development of mood disorders, metabolic disorders, and cancer. However, the influence of ALAN on affective behavior in tumor-bearing mice has not been investigated. We hypothesize that exposure to ALAN accelerates mammary tumor growth and predict that ALAN exacerbates negative affective behaviors in tumor-bearing mice. Adult (> 8 weeks) female C3H mice received a unilateral orthotropic injection of FM3A mouse mammary carcinoma cells (1.0 × 105 in 100 μL) into the fourth inguinal mammary gland. Nineteen days after tumor inoculation, mice were tested for sucrose preference (anhedonia-like behavior). The following day, mice were subjected to an open field test (anxiety-like behavior), followed by forced swim testing (depressive-like behavior). Regardless of tumor status, mice housed in ALAN increased body mass through the first ten days. Tumor-bearing ALAN-housed mice demonstrated reduced latency to tumor onset (day 5) and increased terminal tumor volume (day 21). Exposure to ALAN reduced sucrose preference independent of tumor status. Additionally, tumor-bearing mice housed in dark nights demonstrated significantly increased anxiety-like behavior that was normalized via housing in ALAN. Together, these data reaffirm the negative effects of ALAN on tumorigenesis and demonstrate the potential anxiolytic effect of ALAN in the presence of mammary tumors.

scholarly journals Artificial light at night increases growth and reproductive output in Anolis lizards

2020 ◽  
Vol 287 (1919) ◽  
pp. 20191682 ◽  
Author(s):  
Christopher J. Thawley ◽  
Jason J. Kolbe
Keyword(s):  
Reproductive Output ◽  
Urban Environments ◽  
Egg Laying ◽  
Endocrine Function ◽  
Artificial Light ◽  
Negative Effects ◽  
Light At Night ◽  
Brown Anole ◽  
Negative Impacts ◽  
Growth And Reproduction

Since the invention of electric lighting, artificial light at night (ALAN) has become a defining, and evolutionary novel, feature of human-altered environments especially in cities. ALAN imposes negative impacts on many organisms, including disrupting endocrine function, metabolism, and reproduction. However, we do not know how generalized these impacts are across taxa that exploit urban environments. We exposed brown anole lizards, an abundant and invasive urban exploiter, to relevant levels of ALAN in the laboratory and assessed effects on growth and reproduction at the start of the breeding season. Male and female anoles exposed to ALAN increased growth and did not suffer increased levels of corticosterone. ALAN exposure induced earlier egg-laying, likely by mimicking a longer photoperiod, and increased reproductive output without reducing offspring quality. These increases in growth and reproduction should increase fitness. Anoles, and potentially other taxa, may be resistant to some negative effects of ALAN and able to take advantage of the novel niche space ALAN creates. ALAN and both its negative and positive impacts may play a crucial role in determining which species invade and exploit urban environments.

scholarly journals Reproduction under light pollution: maladaptive response to spatial variation in artificial light in a glow-worm

2020 ◽  
Vol 287 (1931) ◽  
pp. 20200806
Author(s):  
Christina Elgert ◽  
Juhani Hopkins ◽  
Arja Kaitala ◽  
Ulrika Candolin
Keyword(s):  
Spatial Variation ◽  
Environmental Changes ◽  
Artificial Light ◽  
Negative Effects ◽  
Light At Night ◽  
Mate Attraction ◽  
Behavioural Responses ◽  
Individual Fitness ◽  
Maladaptive Response ◽  
The Common

The amount of artificial light at night is growing worldwide, impacting the behaviour of nocturnal organisms. Yet, we know little about the consequences of these behavioural responses for individual fitness and population viability. We investigated if females of the common glow-worm Lampyris noctiluca —which glow in the night to attract males—mitigate negative effects of artificial light on mate attraction by adjusting the timing and location of glowing to spatial variation in light conditions. We found females do not move away from light when exposed to a gradient of artificial light, but delay or even refrain from glowing. Further, we demonstrate that this response is maladaptive, as our field study showed that staying still when exposed to artificial light from a simulated streetlight decreases mate attraction success, while moving only a short distance from the light source can markedly improve mate attraction. These results indicate that glow-worms are unable to respond to spatial variation in artificial light, which may be a factor in their global decline. Consequently, our results support the hypothesis that animals often lack adaptive behavioural responses to anthropogenic environmental changes and underlines the importance of considering behavioural responses when investigating the effects of human activities on wildlife.

The physical environment

2018 ◽  
Author(s):  
Philip James
Keyword(s):  
Physical Environment ◽  
Urban Climate ◽  
Urban Environments ◽  
Artificial Light ◽  
Noise Levels ◽  
Light At Night ◽  
High Noise ◽  
P Elements ◽  
Micro Organisms ◽  
Diversity Of Life

Elements of the physical aspects of urban environments determine which micro-organisms, plants, and animals live in urban environments. In this chapter, climate, air, water, soil, noise, and light are discussed. Urban environments are affected by the climate of the region in which they are located, and in turn and create their own, distinctive urban climate. Air, water, and soil are all affected by urbanization. Pollution of these elements is common. High noise levels and artificial light at night (ALAN—a new phenomenon) are both strongly associated with urban environments. Details of both are discussed. The discussion in this chapter provides a foundation for further exploration of the diversity of life in urban environments and for later exploration of how organisms adapt to urban living, which will be discussed in Parts II and III.

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