Light Pollution Research Articles

Light-Pollution-Monitoring Method for Selected Environmental and Social Elements

Light pollution significantly interferes with animal and human life and should, therefore, be included in the factors that threaten ecosystems. The main aim of this research is to develop a methodology for monitoring environmental and social elements subjected to light pollution in anthropogenic areas. This research is based on yearly and monthly photographs acquired from the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi National Polar-Orbiting Partnership (Suomi NPP) satellite; land cover data from the CORINE Land Cover (CLC) program; and environmental data from the European Environment Agency (EEA) and the World Database on Protected Areas (WDPA). The processing of input data for further analyses, the testing of the methodology and the interpretation of the final results were performed in GIS-type software (ArcGIS Pro). Light pollution in the investigated area was analyzed with the use of maps generated for the years 2014 and 2019. The environmental and social elements were spatially identified in five light pollution classes. The research results demonstrate that the proposed methodology allows for the identification of environmental and social elements that emit light, as well as those that are subjected to light pollution. The methodology used in this work allows us to observe changes resulting from light pollution (decreasing or increasing the intensity). Owing to the use of publicly available data, the methodology can be applied to light pollution monitoring as part of spatial planning in anthropogenic areas. The proposed methodology makes it possible to cover the area exposed to light pollution and to observe (almost online) the environmental and social changes resulting from reductions in light emitted by anthropogenic areas.

Visitor outcomes from dark sky tourism: a case study of the Jasper Dark Sky Festival

ABSTRACT Dark sky tourism is a growing, but under-studied sector of ecotourism. While some research has examined the economic impacts, regional sustainability, and management of dark sky tourism, researchers know little about tourist experiences and outcomes. This study seeks to determine visitor outcomes (satisfaction, learning, attitudes, and behavior changes) among participants at the Jasper Dark Sky Festival in Alberta, Canada. Visitors were middle-aged, balanced between genders, traveled an average of 430 km, and were primarily urban-based. Most were first-time visitors, were present 2 or more days, and attended over 5 festival events. Respondents reported high satisfaction levels, due to the low cost and diversity of events, and welcoming nature of the community, presenters, and volunteers. Respondents reported many areas of learning, particularly about the night sky and night animals. Respondents had very positive attitudes about protecting dark skies, but only 42% planned to change any behaviors to protect dark skies. Study results will help festival organizers design dark sky tourism events to optimize visitor outcomes. In particular, festival organizers can address some barriers to behavioral change, such as stressing the value of dark skies and providing information about how to reduce light pollution.

Residential greenspace exposure, particularly green window-views, is associated with improved sleep quality among older adults: Evidence from a high-density city

Preliminary evidence suggests a potential link between greenspace exposure and better sleep quality. Here we aimed to investigate the specific associations between residential greenspace exposure, green-window views, and sleep quality among older adults and determine whether these associations were mediated through mitigation (i.e., perceived noise annoyance, air pollution, and artificial light pollution) and restoration (i.e., psychological stress) pathways. A total of 1007 older adults with an average age >70 years were recruited from 40 residential communities in the Old City District of Nanjing, China. We developed a set of fine-grained greenspace exposure indices based on 3D point cloud data derived from unmanned aerial vehicle photogrammetry, incorporating vegetation coverage and green volume ratio at the community level and green window ratio at the individual level. Sleep quality was assessed using the Pittsburgh Sleep Quality Index. We examined the complex interrelationships between residential greenspace exposure, environmental stressors (air pollution, artificial light pollution, and noise), perceived mental stress, and sleep quality using multilevel linear regression models. The results suggested the following: (1) Vegetation coverage, green volume ratio, and green window ratio were significantly associated with sleep quality in older adults. (2) The green window ratio was more strongly associated with improved sleep quality than other greenspace exposure metrics. (3) These associations may be partially explained by noise mitigation and mental stress reduction. In conclusion, it seems advantageous to consider immediate residential greenspace, particularly through green-window views, as part of the interventions aimed at supporting sleep quality improvement among older adults.

Blue Light Attracts More Spodoptera frugiperda Moths and Promotes Their Flight Speed.

Light traps are a useful method for monitoring and controlling the important migratory pest, the fall armyworm, Spodoptera frugiperda. Studies have shown that S. frugiperda is sensitive to blue, green, or ultraviolet (UV) light, but the conclusions are inconsistent. Furthermore, conventional black light traps are less effective for trapping S. frugiperda. To improve the trapping efficiency of this pest, it is crucial to determine the specific wavelength to which S. frugiperda is sensitive and measure its flight capability under that wavelength. This study investigated the effects of light wavelength on the phototaxis and flight performance of S. frugiperda. The results showed that blue light was the most sensitive wavelength among the three different LED lights and was unaffected by gender. The flight capability of S. frugiperda varied significantly in different light conditions, especially for flight speed. The fastest flight speed was observed in blue light, whereas the slowest was observed in UV light compared to dark conditions. During a 12 h flight period, speed declined more rapidly in blue light and more slowly in UV, whereas speed remained stable in dark conditions. Meanwhile, the proportion of fast-flying individuals was highest under blue light, which was significantly higher than under UV light. Therefore, the use of light traps equipped with blue LED lights can improve the trapping efficiency of S. frugiperda. These results also provide insights for further research on the effects of light pollution on migratory insects.

Tree removal regulation mitigates light pollution in suburban communities

Light pollution raises various problems for urban environments. This study examined whether or not the tree removal regulation in The Woodlands, Texas, reduced light pollution. Nighttime light intensities for The Woodlands and nearby communities were derived from Visible Infrared Imaging Radiometer Suite (VIIRS) Day and Night Band (DNB) monthly nighttime images. A multi-level model (MLM) was used to examine the effects of built environmental variables on nighttime light intensities in the study communities. The nighttime light intensity was affected by high-intensity developed land, vegetation density, and nighttime light intensity of nearby areas. Then, a control community with similar environmental conditions to The Woodlands was selected, and a paired t-test between The Woodlands and the control community was conducted. The test illustrates that The Woodlands had lower nighttime light intensities than the control community. Based on these results, it is concluded that The Woodlands’ tree removal regulation is effective in mitigating light pollution.

Corals nitrogen and carbon isotopic signatures alters under Artificial Light at Night (ALAN)

This study examines the impact of Artificial Light at Night (ALAN) on two coral species, Acropora eurystoma and Pocillopora damicornis, in the Gulf of Aqaba/Eilat Red Sea, assessing their natural isotopic responses to highlight changes in energy and nutrient sourcing due to sensory light pollution. Our findings indicate significant disturbances in photosynthetic processes in Acropora eurystoma, as evidenced by shifts in δ13C values under ALAN, pointing to alterations in carbon distribution or utilization. In Pocillopora damicornis, similar trends were observed, with changes in δ13C and δ15N values suggesting a disruption in its nitrogen cycle and feeding strategies.The study also uncovers species-specific variations in heterotrophic feeding, a crucial factor in coral resilience under environmental stress, contributing to the corals' fixed carbon budget. Light measurements across the Gulf demonstrated a gradient of light pollution which possess the potential of affecting marine biology in the region. ALAN was found to disrupt natural diurnal tentacle behaviors in both coral species, crucial for prey capture and nutrient acquisition, thereby impacting their isotopic composition and health.Echoing previous research, our study underscores the need to consider each species' ecological and physiological contexts when assessing the impacts of anthropogenic changes. The findings offer important insights into the complexities of marine ecosystems under environmental stress and highlight the urgency of developing effective mitigation strategies.

Effects of artificial light on the arrival time, duration of stay, and departure time of nocturnal flying insects

AbstractInsects with positive phototaxis fly to artificial light sources at night, stay there for a certain amount of time, and then fly away. Although many studies have been conducted on the arrival time of flying insects at artificial light sources, little is known about the time at which they fly away (departure time), duration of stay, and staying time zone. This information is important to protect phototactic insects from the fatal attraction to light that is known as a serious ecological light pollution. In this study, we aimed to identify the duration of stay and staying time zone for various insect species by marking them with light traps. Among the 63 species belonging to 11 orders observed at the study site, cluster analysis focused on 27 species for which 5 or more data points were obtained, highlighting three predominant stay patterns. Type 1 species arrived approximately 1.3 h and flew away approximately 4.1 h after sunset and stayed for a short period of approximately 2.6 h. Type 2 species arrived at approximately 1.2 h and flew away for approximately 9.6 h, with an 8.4 h stay. Type 3 species arrived later than Types 1 and 2, were attracted for 5.4 h, and flew away approximately 13.5 h with an 8.2 h stay. These results suggest that conservation biological countermeasures against light-attracted flying insects need to consider the stay patterns of insects that remain under outdoor lighting.

Embracing firefly flash pattern variability with data-driven species classification

Many nocturnally active fireflies use precisely timed bioluminescent patterns to identify mates, making them especially vulnerable to light pollution. As urbanization continues to brighten the night sky, firefly populations are under constant stress, and close to half of the species are now threatened. Ensuring the survival of firefly biodiversity depends on a large-scale conservation effort to monitor and protect thousands of populations. While species can be identified by their flash patterns, current methods require expert measurement and manual classification and are infeasible given the number and geographic distribution of fireflies. Here we present the application of a recurrent neural network (RNN) for accurate automated firefly flash pattern classification. Using recordings from commodity cameras, we can extract flash trajectories of individuals within a swarm and classify their species with an accuracy of approximately seventy percent. In addition to its potential in population monitoring, automated classification provides the means to study firefly behavior at the population level. We employ the classifier to measure and characterize the variability within and between swarms, unlocking a new dimension of their behavior. Our method is open source, and deployment in community science applications could revolutionize our ability to monitor and understand firefly populations.

Localization and Mapping for Self-Driving Vehicles: A Survey

The upsurge of autonomous vehicles in the automobile industry will lead to better driving experiences while also enabling the users to solve challenging navigation problems. Reaching such capabilities will require significant technological attention and the flawless execution of various complex tasks, one of which is ensuring robust localization and mapping. Recent surveys have not provided a meaningful and comprehensive description of the current approaches in this field. Accordingly, this review is intended to provide adequate coverage of the problems affecting autonomous vehicles in this area, by examining the most recent methods for mapping and localization as well as related feature extraction and data security problems. First, a discussion of the contemporary methods of extracting relevant features from equipped sensors and their categorization as semantic, non-semantic, and deep learning methods is presented. We conclude that representativeness, low cost, and accessibility are crucial constraints in the choice of the methods to be adopted for localization and mapping tasks. Second, the survey focuses on methods to build a vehicle’s environment map, considering both the commercial and the academic solutions available. The analysis proposes a difference between two types of environment, known and unknown, and develops solutions in each case. Third, the survey explores different approaches to vehicle localization and also classifies them according to their mathematical characteristics and priorities. Each section concludes by presenting the related challenges and some future directions. The article also highlights the security problems likely to be encountered in self-driving vehicles, with an assessment of possible defense mechanisms that could prevent security attacks in vehicles. Finally, the article ends with a debate on the potential impacts of autonomous driving, spanning energy consumption and emission reduction, sound and light pollution, integration into smart cities, infrastructure optimization, and software refinement. This thorough investigation aims to foster a comprehensive understanding of the diverse implications of autonomous driving across various domains.

Lipid Peroxidation as the Mechanism Underlying Polycyclic Aromatic Hydrocarbons and Sunlight Synergistic Toxicity in Dermal Fibroblasts.

Light and atmospheric pollution are both independently implicated in cancer induction and premature aging. Evidence has been growing more recently on the toxic synergy between light and pollutants. Polycyclic aromatic hydrocarbons (PAHs) originate from the incomplete combustion of organic matter. Some PAHs, such as the Benzo[a]pyrene (BaP), absorb ultraviolet A (UVA) wavelengths and can act as exogenous chromophores, leading to synergistic toxicity through DNA damage and cytotoxicity concomitant to ROS formation. In this study, we shed light on the mechanism underlying the toxic synergy between PAHs and UVA. Using dermal fibroblasts co-exposed to UVA and BaP, we have demonstrated that the photosensitization reaction causes mortality, which is most likely caused by ROS accumulation. We have shown that these ROS are concentrated in the lipids, which causes an important induction of lipid peroxidation and malondialdehyde, by-products of lipid peroxidation. We have also shown the accumulation of bulky DNA damage, most likely generated by these by-products of lipid peroxidation. To our knowledge, this study represents the first one depicting the molecular effects of photo-pollution on dermal skin.

"Metabolight": how light spectra shape plant growth, development and metabolism.

Innovations in light technologies (i.e. Light Emitting Diodes; LED) and cover films with specific optical features (e.g. photo-selective, light-extracting) have revolutionized crop production in both protected environments and open fields. The possibility to modulate the light spectra, thereby enriching/depleting cultivated plants with targeted wavebands has attracted increasing interest from both basic and applicative research. Indeed, the light environment not only influences plant biomass production but is also a pivotal factor in shaping plant size, development and metabolism. In the last decade, the strict interdependence between specific wavebands and the accumulation of targeted secondary metabolites has been exploited to improve the quality of horticultural products. Innovation in LED lighting has also marked the improvement of streetlamp illumination, thereby posing new questions about the possible influence of light pollution on urban tree metabolism. In this case, it is urgent and challenging to propose new, less-impacting solutions by modulating streetlamp spectra in order to preserve the ecosystem services provided by urban trees. The present review critically summarizes the main recent findings related to the morpho-anatomical, physiological, and biochemical changes induced by light spectra management via different techniques in crops as well as in non-cultivated species. This review explores the following topics: (1) plant growth in monochromatic environments, (2) the use of greenhouse light supplementation, (3) the application of covering films with different properties, and (4) the drawbacks of streetlamp illumination on urban trees. Additionally, it proposes new perspectives offered by in planta photomodulation.

Time is of the essence: The importance of considering biological rhythms in an increasingly polluted world.

Biological rhythms have a crucial role in shaping the biology and ecology of organisms. Light pollution is known to disrupt these rhythms, and evidence is emerging that chemical pollutants can cause similar disruption. Conversely, biological rhythms can influence the effects and toxicity of chemicals. Thus, by drawing insights from the extensive study of biological rhythms in biomedical and light pollution research, we can greatly improve our understanding of chemical pollution. This Essay advocates for the integration of biological rhythmicity into chemical pollution research to gain a more comprehensive understanding of how chemical pollutants affect wildlife and ecosystems. Despite historical barriers, recent experimental and technological advancements now facilitate the integration of biological rhythms into ecotoxicology, offering unprecedented, high-resolution data across spatiotemporal scales. Recognizing the importance of biological rhythms will be essential for understanding, predicting, and mitigating the complex ecological repercussions of chemical pollution.

Dietary tryptophan alleviates intestinal inflammation caused by long photoperiod via gut microbiota derived tryptophan metabolites-NLRP3 pathway in broiler chickens

Light pollution is a potential risk factor for intestinal health. Tryptophan plays an important role in the inhibition of intestinal inflammation. However, the mechanism of tryptophan in alleviating intestinal inflammation caused by long photoperiod is still unclear. This study investigated the anti-inflammatory effect of dietary tryptophan on intestinal inflammatory damage induced by long photoperiod and its potential mechanism in broiler chickens. We found that dietary tryptophan mitigated long photoperiod-induced intestinal tissue inflammatory damage and inhibited the activation of Nucleotide-Binding Oligomerization Domain, Leucine-Rich Repeat and Pyrin Domain-Containing 3 inflammasome. Moreover, dietary tryptophan significantly increased the relative abundance of Faecalibacterium, Enterococcus, and Lachnospiraceae_NC2004_group were significantly decreased the relative abundance of Ruminococcus_torques_group and norank_f_UCG-010 under the condition of long photoperiod (P < 0.05). The results of tryptophan targeted metabolomics show that tryptophan significantly increased indole-3-acetic acid (IAA) and indole-3 lactic acid (ILA), and significantly decreased xanthurenic acid (XA) under long photoperiod (P < 0.05). In conclusion, the results indicated that dietary tryptophan alleviates intestinal inflammatory damage caused by long photoperiod via the inhibition of Nucleotide-Binding Oligomerization Domain, Leucine-Rich Repeat and Pyrin Domain-Containing 3 inflammasome activation, which was mediated by tryptophan metabolites. Therefore, tryptophan supplementation could be a promising way to protect the intestine health under the condition of long photoperiod.

Light pollution disrupts circadian clock gene expression in two mosquito vectors during their overwintering dormancy

Artificial light at night (ALAN) is an increasingly important form of environmental disturbance as it alters Light:Dark cycles that regulate daily and seasonal changes in physiology and phenology. The Northern house mosquito (Culex pipiens) and the tiger mosquito (Aedes albopictus) enter an overwintering dormancy known as diapause that is cued by short days. These two species differ in diapause strategy: Cx. pipiens diapause as adult females while Ae. albopictus enter a maternally-programmed, egg diapause. Previous studies found that ALAN inhibits diapause in both species, but the mechanism is unknown. As the circadian clock is implicated in the regulation of diapause in many insects, we examined whether exposure to ALAN altered the daily expression of core circadian cloc genes (cycle, Clock, period, timeless, cryptochrome 1, cryptochrome 2, and Par domain protein 1) in these two species when reared under short-day, diapause-inducing conditions. We found that exposure to ALAN altered the abundance of several clock genes in adult females of both species, but that clock gene rhythmicity was maintained for most genes. ALAN also had little effect on clock gene abundance in mature oocytes that were dissected from female Ae. albopictus that were reared under short day conditions. Our findings indicate that ALAN may inhibit diapause initiation through the circadian clock in two medically-important mosquitoes.

Risk Assessment of Metals in Black Fungus and Culture Substrates Based on Monte Carlo Simulation

Black fungus is the second-most consumed edible fungus in China. The establishment of a risk assessment mechanism for heavy metals in black fungus is particularly critical to the safety of edible fungi. To clarify a risk assessment mechanism of heavy metal pollution of edible fungi in northeast China, in this study, the contents of Pb, Cr, CD and As in 415 samples were determined, and a total of 1660 valid data were obtained. Then, based on Monte Carlo simulation, a non-parametric probability assessment system for heavy metals in black fungus was established and improved. The results showed that the residual amounts of As, Pb, Cd and Cr in black fungus were in the order of Cr &gt; Pb &gt; As &gt; Cd. The background content of four heavy metals in the main raw materials was preliminarily clarified. Among them, the content of As is between 0.010–0.320 mg·kg−1, Pb is between 0.051–0.792 mg·kg−1, Cd is between 0.019–0.236 mg·kg−1, and Cr is between 0.06–3.41 mg·kg−1. These results indicate that the dietary exposure risk of heavy metals ingested by dried black fungus in Chinese minors and adults is basically safe, but at the high exposure levels of 97.5% sites and 99% sites, Cr is at the light pollution level, and the comprehensive pollution of four heavy metals is at the moderate pollution level. In addition, this study found that raw materials can cause heavy metal accumulation in black fungus, mainly from sawdust, followed by rice bran and wheat bran.

Behavioral responses of cave-roosting bats to artificial light of different spectra and intensities: Implications for lighting management strategy

Artificial light at night has become an emerging environmental pollutant, posing a serious threat to biodiversity. Cave-roosting animals are vulnerable to light pollution due to long-term adaptation to nocturnal niches, and the problem is especially severe in the context of cave tourism and limestone mining. Mitigating the adverse impacts of artificial light on cave-dwelling animals presents a challenge. This study aimed to assess the relative contributions of spectral parameters and light intensity to the emergence behavior of nine cave-roosting bat species: Rhinolophus macrotis, Rhinolophus pearsonii, Rhinolophus rex, Rhinolophus pusillus, Rhinolophus siamensis, Rhinolophus sinicus, Hipposideros armiger, Myotis davidii, and Miniopterus fuliginosus. We manipulated light spectra and intensities through light-emitting diode (LED) lighting and gel filters at the entrance of bat roost. We monitored nightly passes per species to quantify bat emergence under the dark control and ten lighting conditions (blue, green, yellow, red, and white light at high and low intensities) using ultrasonic recording. Our analyses showed that the number of bat passes tended to be reduced in the presence of white, green, and yellow light, independent of light intensity. In contrast, the number of bat passes showed no pronounced differences under the dark control, blue light, and red light. The number of bat passes was primarily affected by LED light's blue component, red component, peak wavelength, and half-width instead of light intensity. These results demonstrate that spectral parameters of LED light can significantly affect emergence behavior of cave-dwelling bats. Our findings highlight the importance of manipulating light colors to reduce the negative impacts of light pollution on cave-roosting bats as a function of their spectral sensitivity. We recommend the use of gel filters to manage existing artificial lighting systems at the entrance of bat-inhabited caves.

Study on Regional Light Pollution Risk Classification Based on Game Combination—Rank Sum Ratio Method

Study on Regional Light Pollution Risk Classification Based on Game Combination—Rank Sum Ratio Method

Artificial light at night affects the timing of roosting by Chimney Swifts

Understanding the impact of anthropogenic threats, such as light pollution, on biodiversity is necessary to establish effective guidelines to protect diminishing wildlife. In this study, we examined the effect of artificial light at night (ALAN) on the roosting behaviour of Chimney Swifts Chaetura pelagica, a highly threatened migratory bird species that lives commensally with humans, where it often breeds and roosts in artificial structures such as chimneys. Although Chimney Swifts are known to use time of sunset in combination with temperature, wind and season to coordinate roost entry, we predicted that high ALAN exposure would override these natural cues and lead to a delayed entry compared with sites with less light pollution. To test this, we examined the effects of ALAN on the start and end times of entry to 21 roosting sites located along a light pollution gradient in New Jersey and the New York Metropolitan area. We found that ALAN was a significant predictor of roosting entry time, with birds entering later in sites with more light pollution. While Chimney Swifts initiated roosting earlier in the summer months compared with the autumn, this effect was absent in areas with high light pollution. These findings highlight the need to determine the causes and consequences of light pollution effects.

Research note: Red light to mitigate light pollution: Is it possible to balance functionality and ecological impact?

The widespread use of electric lighting has revolutionised society but brought unintended consequences, notably light pollution, impacting ecosystems and human circadian rhythms. Concerns about anthropogenic light at night (ALAN) have prompted innovative solutions, such as spectral tuning of light sources. In Europe, a recent focus involves the enforcement of red light in outdoor settings to minimise ALAN’s impact, particularly on bats. This mini review synthesises literature to provide an overview of the advantages and disadvantages of the use of red light outdoors. There is a need for further examination of the potential ecological consequences of red light, considering challenges in lighting design functionality and broader impacts on diverse species.

An Implementation of Lighting Control Systems Buildings with Time Based Mapping and AC Light Dimmer Integrated IoT

The use of a building lighting control system is very necessary to regulate lighting in a building to suit needs, because not only low lighting conditions can cause discomfort, lighting conditions that are too bright can also cause discomfort. The problem is that natural light cannot play much of a role in lighting buildings which are generally closed and have minimal ventilation, as well as the availability of lighting which, if not controlled properly, cannot directly meet the lighting needs of the building, whether it is the value of the light intensity produced, mapping the lighting of the lights, setting the duration of the use of lights as lighting or in the case of excessive lighting by turning on all the available lights in the room becomes a problem in terms of efficient use of electrical energy, so a special system design is needed to overcome this problem, namely the implementation of a building lighting control system. with time-based mapping and an AC light dimmer integrated with the Internet of Things which has a specific purpose as a system for controlling building lighting to suit needs, whether it is setting the light intensity value, mapping the use of lights or setting the time of use of lights as lighting. The test results have shown that the implementation system for the building lighting control system with time-based mapping and AC Light Dimmer which has been integrated with the Internet of Things as remote control and monitoring communication has been successfully implemented and is working well according to the specified targets. Keywords: lighting, AC light dimmer, mapping, Internet of Things.