scholarly journals The dark side of artificial light

2020 ◽  
Vol 42 (5) ◽  
pp. 32-35
Author(s):  
Jun Yang ◽  
David A Hendrix ◽  
Jadwiga M Giebultowicz

Light is necessary for life, but increasing exposure to artificial light may be detrimental to human health. With prevalent use of light-emitting diodes (LEDs) in ambient lighting and electronic devices, humans are increasingly exposed to blue light that appears white due to addition of other colours. Excessive blue light can damage eyes, but it is not known whether daily LED exposure across lifespan may have other adverse health effects. A recent study in short-lived model organism Drosophila melanogaster revealed that cumulative, long-term exposure to blue light impacts brain function, accelerates the aging process and significantly shortens lifespan compared to flies maintained in constant darkness or in white light with blue wavelengths blocked. Increased mortality and brain neurodegeneration was also observed in flies with genetically ablated eyes, demonstrating damage to non-retinal cells. As molecular responses to light are similar in the cells of both fruit flies and humans, these studies suggest that lifelong daily blue light exposure may impair cellular health in humans.

Author(s):  
Trevor R. Nash ◽  
Eileen S. Chow ◽  
Alexander D. Law ◽  
Samuel D. Fu ◽  
Elzbieta Fuszara ◽  
...  

Abstract Light is necessary for life, but prolonged exposure to artificial light is a matter of increasing health concern. Humans are exposed to increased amounts of light in the blue spectrum produced by light-emitting diodes (LEDs), which can interfere with normal sleep cycles. The LED technologies are relatively new; therefore, the long-term effects of exposure to blue light across the lifespan are not understood. We investigated the effects of light in the model organism, Drosophila melanogaster, and determined that flies maintained in daily cycles of 12-h blue LED and 12-h darkness had significantly reduced longevity compared with flies maintained in constant darkness or in white light with blue wavelengths blocked. Exposure of adult flies to 12 h of blue light per day accelerated aging phenotypes causing damage to retinal cells, brain neurodegeneration, and impaired locomotion. We report that brain damage and locomotor impairments do not depend on the degeneration in the retina, as these phenotypes were evident under blue light in flies with genetically ablated eyes. Blue light induces expression of stress-responsive genes in old flies but not in young, suggesting that cumulative light exposure acts as a stressor during aging. We also determined that several known blue-light-sensitive proteins are not acting in pathways mediating detrimental light effects. Our study reveals the unexpected effects of blue light on fly brain and establishes Drosophila as a model in which to investigate long-term effects of blue light at the cellular and organismal level.


Polar Biology ◽  
2021 ◽  
Vol 44 (3) ◽  
pp. 483-489
Author(s):  
Bjørn A. Krafft ◽  
Ludvig A. Krag

AbstractThe use of light-emitting diodes (LEDs) is increasingly used in fishing gears and its application is known to trigger negative or positive phototaxis (i.e., swimming away or toward the light source, respectively) for some marine species. However, our understanding of how artificial light influences behavior is poorly understood for many species and most studies can be characterized as trial and error experiments. In this study, we tested whether exposure to white LED light could initiate a phototactic response in Antarctic krill (Euphausia superba). Trawl-caught krill were used in a controlled artificial light exposure experiment conducted onboard a vessel in the Southern Ocean. The experiment was conducted in chambers with dark and light zones in which krill could move freely. Results showed that krill displayed a significant positive phototaxis. Understanding this behavioral response is relevant to development of krill fishing technology to improve scientific sampling gear, improve harvest efficiency, and reduce potential unwanted bycatch.


Marine Drugs ◽  
2020 ◽  
Vol 18 (8) ◽  
pp. 387 ◽  
Author(s):  
Chao-Wen Lin ◽  
Chung-May Yang ◽  
Chang-Hao Yang

Light-emitting diodes (LEDs) are widely used and energy-efficient light sources in modern life that emit higher levels of short-wavelength blue light. Excessive blue light exposure may damage the photoreceptor cells in our eyes. Astaxanthin, a xanthophyll that is abundantly available in seafood, is a potent free radical scavenger and anti-inflammatory agent. We used a 661W photoreceptor cell line to investigate the protective effect of astaxanthin on blue light LED-induced retinal injury. The cells were treated with various concentrations of astaxanthin and then exposed to blue light LED. Our results showed that pretreatment with astaxanthin inhibited blue light LED-induced cell apoptosis and prevented cell death. Moreover, the protective effect was concentration dependent. Astaxanthin suppressed the production of reactive oxygen species and oxidative stress biomarkers and diminished mitochondrial damage induced by blue light exposure. Western blot analysis confirmed that astaxanthin activated the PI3K/Akt pathway, induced the nuclear translocation of Nrf2, and increased the expression of phase II antioxidant enzymes. The expression of antioxidant enzymes and the suppression of apoptosis-related proteins eventually protected the 661W cells against blue light LED-induced cell damage. Thus, our results demonstrated that astaxanthin exerted a dose-dependent protective effect on photoreceptor cells against damage mediated by blue light LED exposure.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nathan Stasko ◽  
Jacob F. Kocher ◽  
Abigail Annas ◽  
Ibrahim Henson ◽  
Theresa S. Seitz ◽  
...  

AbstractThe delivery of safe, visible wavelengths of light can be an effective, pathogen-agnostic, countermeasure that would expand the current portfolio of SARS-CoV-2 intervention strategies beyond the conventional approaches of vaccine, antibody, and antiviral therapeutics. Employing custom biological light units, that incorporate optically engineered light-emitting diode (LED) arrays, we harnessed monochromatic wavelengths of light for uniform delivery across biological surfaces. We demonstrated that primary 3D human tracheal/bronchial-derived epithelial tissues tolerated high doses of a narrow spectral band of visible light centered at a peak wavelength of 425 nm. We extended these studies to Vero E6 cells to understand how light may influence the viability of a mammalian cell line conventionally used for assaying SARS-CoV-2. The exposure of single-cell monolayers of Vero E6 cells to similar doses of 425 nm blue light resulted in viabilities that were dependent on dose and cell density. Doses of 425 nm blue light that are well-tolerated by Vero E6 cells also inhibited infection and replication of cell-associated SARS-CoV-2 by > 99% 24 h post-infection after a single five-minute light exposure. Moreover, the 425 nm blue light inactivated cell-free betacoronaviruses including SARS-CoV-1, MERS-CoV, and SARS-CoV-2 up to 99.99% in a dose-dependent manner. Importantly, clinically applicable doses of 425 nm blue light dramatically inhibited SARS-CoV-2 infection and replication in primary human 3D tracheal/bronchial tissue. Safe doses of visible light should be considered part of the strategic portfolio for the development of SARS-CoV-2 therapeutic countermeasures to mitigate coronavirus disease 2019 (COVID-19).


Author(s):  
Stephanie A. T. Brown ◽  
Linda L. DeSimone ◽  
Tina M. Burke

In the digital age, the military is developing cutting edge technologies (e.g., heads-up and mixed reality displays, night vision devices, etc.) to maximize situational awareness and effectiveness. Effects of light exposure from screen-based systems on our Soldier-operators has not been fully considered. Some literature concludes that evening blue light exposure preceding bedtime can result in increased alertness and may negatively impact sleep, producing negative moodstates and sleepiness upon wakening. The current study looks at blue light exposure and subsequent sleep of forty-six Soldiers during a company-wide field exercise utilizing wrist-worn actigraphy and light sensors. Observations indicate periods of blue light exposure during evening field operations were followed by sleep intervals with significant decrements in sleep quality. Future studies will isolate the effects of military-specific blue light emitting device exposure in high contrast, low ambient light environments on sleep quality, providing specific guidance and interventions to reduce negative impacts on operations.


2020 ◽  
Vol 12 (10) ◽  
pp. 4263 ◽  
Author(s):  
David Baeza Moyano ◽  
Mónica San Juan Fernández ◽  
Roberto Alonso González Lezcano

In recent years, articles have been published on the non-visual effects of light, specifically the light emitted by the new luminaires with light emitting diodes (LEDs) and by the screens of televisions, computer equipment, and mobile phones. Professionals from the world of optometry have raised the possibility that the blue part of the visible light from sources that emit artificial light could have pernicious effects on the retina. The aim of this work is to analyze the articles published on this subject, and to use existing information to elucidate the spectral composition and irradiance of new LED luminaires for use in the home and in public spaces such as educational centers, as well as considering the consequences of the light emitted by laptops for teenagers. The results of this research show that the amount of blue light emitted by electronic equipment is lower than that emitted by modern luminaires and thousands of times less than solar irradiance. On the other hand, the latest research warns that these small amounts of light received at night can have pernicious non-visual effects on adolescents. The creation of new LED luminaires for interior lighting, including in educational centers, where the intensity of blue light can be increased without any specific legislation for its control, makes regulatory developments imperative due to the possible repercussions on adolescents with unknown and unpredictable consequences.


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