Light Pollution Levels Research Articles

Sleep deserts: a key determinant of sleep inequities.

Sleep deserts: a key determinant of sleep inequities.

Even low light pollution levels affect the spatial distribution and timing of activity of a “light tolerant” bat species

By disrupting nocturnal landscapes worldwide, light pollution caused by Artificial Light At Night (ALAN) is recognized as a major threat to biodiversity. As even low light intensities might affect some taxa, concerns are arising about biological responses to widespread low light levels. We used data from a French citizen science bat monitoring program (1894 full-nights monitored on 1055 sites) to explore the landscape-scale effects of light on an open-space-foraging bat species, the Serotine bat (Eptesicus serotinus). We assessed this species' abundance and timing of night-time activity (median time of activity) at foraging sites. ALAN, and to a lesser extent moonlight, reduced E. serotinus abundance. ALAN delayed activity, and this delay was amplified during overcast nights. On the contrary, where there was no ALAN, the higher the cloud cover, the earlier the activity occurred. Cloud cover likely darkened the night sky in rural locations, whereas it amplified skyglow in light-polluted places, increasing ALAN effects on bats. Interestingly, moonlight also delayed activity but this effect was weakened where there was ALAN. Our study shows that even fine variations of light levels could affect the spatiotemporal distribution of a common species usually considered to be “light tolerant”, with potential cascading effects on individual fitness and population dynamics. It stresses how urgent it is to preserve and restore dark areas to protect biodiversity from light pollution while working on light intensity and directivity where ALAN is needed.

Pollution level of Banjaran River, Banyumas District, Indonesia: A study based on the Saprobic Index of periphytic microalgae

Abstract. Samudra SR, Fitriadi R, Baedowi M, Sari LK. 2022. Pollution level of Banjaran River, Banyumas District, Indonesia: A study based on the Saprobic Index of periphytic microalgae. Biodiversitas 23: 1527-1534. The saprobic index of periphytic microalgae can be used to determine the level of water pollution based on the number and composition of species. Banjaran River is one of the rivers in the Banyumas District, Central Java, Indonesia, which is widely used by the local people for daily activities. The increase of domestic and agricultural activities in the river triggers an increase in the pollutants input into the river. This study aims to determine the status of the waters in the midstream of Banjaran River by using the periphytic microalgae saprobic index as a bioindicator of water quality. Purposive sampling method was used in this study by establishing four stations and five replications at each station. The result showed that the abundance of periphytic microalgae ranged from 7,547-8,733 cells/cm2; the diversity index ranged from 1.64-2.07 (moderately polluted waters); the dominance index ranged from 0.21-0.26 (no particular species of periphytic microalgae dominating the four stations); and saprobic index value of Banjaran River ranged from 1.00 to 1.03 which indicates that Banjaran River belongs to ?-meso/oligo saprobic water. In other words, it was water with a light pollution level. An action to reduce organic pollution is necessary, one of which is by reducing the people's activities such as washing and disposing of household waste into the river so that the condition of Banjaran River can be maintained properly and reduce pollution in its subsequent river flows.

Light pollution as an ecological edge effect: Landscape ecological analysis of light pollution in protected areas in Korea

Protected areas have been increasingly encroached upon by light pollution. This paper examines whether patch geometry and land development intensities in protected areas affect the light pollution levels in 22 Korean national parks. Light pollution levels were assessed based on mean nighttime radiance of these national parks derived from nighttime satellite images. Total floor areas of buildings in the parks and in a 1 km buffer zone outside the park boundaries were calculated to assess land development intensities both inside and surrounding the parks. Two landscape metrics (patch area and fractal dimension) were measured to assess the patch geometry of the parks. Results show that the mean nighttime radiances in the Korean national parks are significantly affected by total floor areas in the 1 km buffer zone, but not by the total floor area within the park. This suggests that skyglow caused by artificial light in periphery is a major source of light pollution in the Korean national parks. In other words, light pollution can be seen as an ecological edge effect in protected areas where land development is stringently restricted. This conclusion is also supported by significant effects of two patch geometry variables, i.e., light pollution was more severe in a protected area with smaller size and a more complex shape. Based on these findings, it is suggested to make protected areas larger and more simple-shaped to protect biodiversity from light pollution. Managing lights in periphery of protected areas is also suggested.

Tracking Flights to Investigate Seabird Mortality Induced by Artificial Lights

Light pollution causes attraction and/or disorientation of seabirds, leading to mortality events due to multiple threats. This is a poorly understood phenomenon, largely because of the challenge to track seabirds at night from their nests to the grounding light-polluted locations. New tracking technologies can inform about this phenomenon. Here, we used GPS transmitters with remote download to track the flights of Cory’s shearwaterCalonectris borealisfledglings from an inland experimental releasing site to the ocean. We released birds assigned to three experimental groups: GPS tagged, tape-labelled, and control birds. We assessed how both intrinsic (such as body mass, body condition, body size, and down abundance) and extrinsic (i.e., flight descriptors, such as distance, straightness, and flight duration, wind speed, or moon luminance) factors influenced light-induced groundings by using two datasets: one including the three groups and another including just the GPS tagged birds (as GPS devices provide unique information). We tested whether the probability of being grounded by artificial lights was related to intrinsic factors. With the use of the whole dataset, we found that birds with a higher down abundance had a higher probability of being grounded. GPS data revealed that the probability of being grounded was positively related to the tortuosity of flights and the overflown light pollution levels. Also, birds with slower flights were more likely to be grounded than birds with fast flights. Tortuosity increased with light pollution levels but decreased with the ambient light of the moon. GPSs with remote data download provided information on birds reaching the ocean, this being a substantial improvement to previous studies requiring recapture of the individuals to retrieve the data. GPS tracks of birds reaching the ocean allowed us to know that some birds overflew coastal urban areas so light-polluted as the landing sites of grounded birds. We provide novel scientific-based information to manage seabird mortality induced by artificial lights.

Light pollution mapping in Pécs city with the help of SQM-L and VIIRS DNB: The effect of public luminaire replacements on the sky background of the urban sky

Recently light pollution has been one of the most dynamically increasing form of environmental pollution. Light, if it arrives at the wrong place, time, quantity and quality, is harmful to human health and the physical environment-not to mention that it is a mere waste of energy. The brightness of the sky above Pécs was measured by SQM-L instruments in 2011 and 2019. Maps of the different neighbourhoods with different levels of light pollution have been prepared. In addition, special VIIRS day/night band satellite images were also analysed using QGIS software. Our investigations coincided with the modernization of street lighting in the city. The impact of LED illuminators installed along main roads in Pécs was observed locally.

DEVELOPMENT OF THE PUGUNG RAHARJO ARCHAEOLOGICAL PARK IN LAMPUNG PROVINCE WITH GEOPARK AND ASTROTOURISM CONCEPT


 
 
 
 Pugung Raharjo Archaeological Park is an archaeological site covering a 30 hectares area in East Lampung Regency, Lampung Province. There is some evidence of the megalithic era, also called the stepped pyramid of Pugung Raharjo discovered in 1957. There are other megalithic buildings from the 12th to 16th centuries AD, including menhirs and dolmen and prehistoric remains dating back to 2500 BC. From a geological perspective, Pugung Raharjo Archaeological Park was built on the extent of vesicular basalt lava of the Sukadana Formation, which is situated above the top of the Sukadana Basalt Plateau. These stones even have a local designation referred to as 'curly stones' because of their rough texture and vesicular holes. Due to its good strength and adhe-sion, the people of East Lampung use this stone as their house foundation. These stone is also used to make pundan berundak, menhirs, dolmen and others. The use of local stone for buildings and daily life tools shows a strong connection between geological and cultural aspects. The Pugung Raharjo Site area is also a very suitable location for astronomical observations because of the low level of light pollution. Moreover, according to history, people have been familiar with astronomy in their daily lives, such as wor-ship, time markers, navigation, or directions. This gives reach to a hypothesis about the possibility of this ancient society's astro-nomical knowledge manifested in determining each object's position in an area with specific constellation patterns. Based on its potential, Pugung Raharjo Archaeological Park is very suitable for developing the Geopark concept, which integrates geological, biological, and cultural aspects.
 
 
 

Top ten birds indicators of high environmental quality in European cities

Urban and suburban areas are among the fastest-growing land-use types globally, reducing and fragmenting natural habitats for many animal species and making human-wildlife interactions more common. However, cities also create habitat for several species considered urban tolerant or urban exploiter species. Additionally, the environmental characteristics of urban areas can strongly affect the life quality of citizens. This study aimed to assess the effectiveness of common bird species as indicators of urban areas with high environmental quality within cities. Our study recorded 128 bird species in 1441 point counts distributed in fifteen different European cities. We classified urban areas as “high environmental quality” – HEQ when they were simultaneously characterized by a high vegetation cover and heterogeneity, low level of light pollution, and avian communities with high potential resilience to face ecological stress. Species indicators of HEQ urban areas were identified using the species-level indicator value (IndVal) analysis. Such species can be used as ecological indicators of HEQ in different European cities. The list of top ten birds indicators of HEQ in European cities is led by the Eurasian blackcap, selected as an indicator in more than half of the survey cities. Other birds indicators of HEQ in multiple cities are Blackbird (47%), Great tit (40%), Blue tit, Tree sparrow and Magpie (all 33%). The mean specificity of the top-ranked bird indicator of HEQ urban areas (Eurasian blackcap) was 0.778. Most of the HEQ-indicators are resident or resident/short migratory species characterized by territorial behaviour. Our findings support using multiple species as bioindicators of urban changes by using specific groups with few common species as surrogates of HEQ urban areas. The approach proposed in this study can be applied in different European cities to monitor biodiversity status periodically, even involving citizen science initiatives.

Impact of Optical Aerosol Depth (AOD) on Light Pollution Level: a spatio-temporal analysis

Population dynamics and economical, also industrial, in Indonesia are growth as it increasing every years. It brings an environmental problems unconsciously. Increasing the amount of aerosol optical depth (AOD) has a considerable impact, one of them is light pollution increase due to uncontrolled scattering of particles in urban areas. Light pollution is a new problem, it can disturb the balance of the ecosystem. Increasing light pollution on trophosperic surface on the earth can cause the functional damage of natural light in the sky in providing guidance for animal noctural animals and human health. The consequence are emergencing problems with ecosystem imbalances that can be a new disasters in the future. Identification of the impact of increasing AOD with light pollution needs to be known to maintain the balance of the ecosystem in the future. Remote sensing has an effective, efficient and able to provide actual data on this problem. MODIS imagery was used as AOD and VIIRS DNB data sources were used for multi-temporal light pollution data in 2014, 2016 and 2018. Both data were then performed correlation tests using Rank Spearment methods and obtained very strong results, 0.8-1. The higher AOD in urban areas, the higher the level of light pollution in the region. Java and Bali have high AOD levels accompanied by high light pollution.

Overview of a method for lighting the facades of historic buildings by considering light pollution as a design factor

The objective of this research is the study of lighting the facades of historic buildings having as an orientation the reduction of dire effects of light pollution on the environment and humans. Lighting is an important way of underlining characteristics of historic buildings, such as beauty and identity, which form part of our cultural heritage. Scientists have outlined the effects of light pollution on the environment and people and therefore the lighting designer should apply efficient lighting design proposals that are environmentally and human friendly, according to the architecture of a building. This research proposes a methodology for calculating the levels of light pollution that are caused by different exterior lighting scenarios for historic buildings.

An Impact Analysis of Artificial Light at Night (ALAN) on Bats. A Case Study of the Historic Monument and Natura 2000 Wisłoujście Fortress in Gdansk, Poland.

The artificial light at night (ALAN) present in many cities and towns has a negative impact on numerous organisms that live alongside humans, including bats. Therefore, we investigated if the artificial illumination of the historic Wisłoujście Fortress in Gdańsk, Poland (part of the Natura 2000 network), during nighttime events, which included an outdoor electronic dance music (EDM) festival, might be responsible for increased light pollution and the decline in recent years of the pond bat (Myotis dasycneme). An assessment of light pollution levels was made using the methods of geographical information system (GIS) and free-of-charge satellite remote sensing (SRS) technology. Moreover, this paper reviewed the most important approaches for environmental protection of bats in the context of ecological light pollution, including International, European, and Polish regulatory frameworks. The analysis of this interdisciplinary study confirmed the complexity of the problem and highlighted, too, the need for better control of artificial illumination in such sensitive areas. It also revealed that SRS was not the best light pollution assessment method for this particular case study due to several reasons listed in this paper. As a result, the authors’ proposal for improvements also involved practical recommendations for devising suitable strategies for lighting research and practice in the Natura 2000 Wisłoujście Fortress site located adjacent to urban areas to reduce the potential negative impact of ALAN on bats and their natural habitats.

Light pollution as a factor in breast and prostate cancer

Light pollution is a global environmental issue that affects photosensitive organisms. For instance, several researchers have recognized melatonin suppression in humans as a direct cause of long-term exposure to high artificial light levels at night. Others have identified low melatonin levels as a risk factor for a higher prevalence of hormone-sensitive cancer. This paper analyzes the association between light pollution, estimated as the emission analysis of satellite worldwide nighttime light collections from 1999 to 2012, and 25,025 breast and 16,119 prostate cancer events from 2003 to 2012. Both types of cancer increased during the study period, but light pollution increased in urban and peri-urban areas and decreased in rural areas. Cumulative light pollution during 5 years showed a positive association with breast cancer but not with prostate cancer. The association between light pollution and breast cancer persisted when adjusted to age-standardized rates with a mean increase of 10.9 events per 100,000 population-year (95% confidence interval 7.0 to 14.8). We conclude that exposure to elevated light pollution levels could be a risk factor for breast cancer in Slovakia. This work can interest researchers who study relationships between atmospheric pollutants and the growing cancer epidemic. The results and the methodology can be extrapolated to any country in the world if data is available.

Avoidance of different durations, colours and intensities of artificial light by adult seabirds

There is increasing evidence for impacts of light pollution on the physiology and behaviour of wild animals. Nocturnally active Procellariiform seabirds are often found grounded in areas polluted by light and struggle to take to the air again without human intervention. Hence, understanding their responses to different wavelengths and intensities of light is urgently needed to inform mitigation measures. Here, we demonstrate how different light characteristics can affect the nocturnal flight of Manx shearwaters Puffinus puffinus by experimentally introducing lights at a colony subject to low levels of light pollution due to passing ships and coastal developments. The density of birds in flight above the colony was measured using a thermal imaging camera. We compared number of flying shearwaters under dark conditions and in response to an artificially introduced light, and observed fewer birds in flight during ‘light-on’ periods, suggesting that adult shearwaters were repelled by the light. This effect was stronger with higher light intensity, increasing duration of ‘light-on’ periods and with green and blue compared to red light. Thus, we recommend lower light intensity, red colour, and shorter duration of ‘light-on’ periods as mitigation measures to reduce the effects of light at breeding colonies and in their vicinity.

Habitat-Related Differences in Winter Presence and Spring–Summer Activity of Roe Deer in Warsaw

Preliminary research conducted in Warsaw in the 1970s and 2000s showed that roe deer (Capreolus capreolus) stayed in forest habitat and avoided anthropogenic areas. Activity and exploration patterns of animals are shaped by indices of anthropogenic disturbances, elevated in large cities. The aims of the study were (1) to compare the presence of roe deer in natural and anthropogenic habitats of Warsaw during three periods: 1976–1978, 2005–2008 and 2017–2021, based on snow tracking on transect routes (681.2 km in total), and (2) to describe the presence and activity of roe deer in relation to human disturbances in selected urban forests in its reproductive period (March–August), based on camera trap survey (2019–2020, 859 observations, 5317 trap-days in total). The number of tracks was higher in natural habitat during all three periods, with the highest value in 2017–2021 (9.85/km/24h). The peak of roe deer activity was recorded at dusk, and it changed with moon phases between spring and summer. Landscape connectivity and level of light pollution did not affect the activity pattern of roe deer. Our research showed that roe deer inhabiting urban areas avoided human presence by using well-covered habitats and being active in periods when the level of human disturbance was lower.

Effects of urbanization on taxonomic, functional and phylogenetic avian diversity in Europe

Europe is an urbanized continent characterized by a long history of human-wildlife interactions. This study aimed to assess the effects of specific elements of urbanization and urban pollution on complementary avian diversity metrics, to provide new insights on the conservation of urban birds.Our study recorded 133 bird species at 1624 point counts uniformly distributed in seventeen different European cities. Our results thus covered a large spatial scale, confirming both effects of geographical and local attributes of the cities on avian diversity. However, we found contrasting effects for the different diversity components analyzed. Overall, taxonomic diversity (bird species richness), phylogenetic diversity and relatedness were significantly and negatively associated with latitude, while functional dispersion of communities showed no association whatsoever. At the local level (within the city), we found that urban greenery (grass, bush, and trees) is positively correlated with the number of breeding bird species, while the building cover showed a detrimental effect. Functional dispersion was the less affected diversity metric, while grass and trees and water (rivers or urban streams) positively affected the phylogenetic diversity of avian communities. Finally, the phylogenetic relatedness of species increased with all the main indicators of urbanization (building surface, floors, pedestrian's density and level of light pollution) and was only mitigated by the presence of bushes.We argue that maintaining adequate levels of avian diversity within the urban settlements can help to increase the potential resilience of urban ecosystems exposed to the stress provoked by rapid and continuous changes. We listed some characteristics of the cities providing positive and negative effects on each facet of urban avian diversity.

Why be afraid of the night? - Pedagogical methods for developing positive attitudes towards natural darkness in order to reduce light pollution

Human existence has always been accompanied by our fear of the dark. Based on the theory of runaway selection (Fisher, 1930), it can be concluded that the innate feeling of fear associated with darkness can also be related to increased levels of light pollution of modern era. Although it is not possible and would also be undesirable to eliminate this fear, there is a pedagogical opportunity to develop positive attitudes towards the night, which may also lead to a reduction in light pollution in the future. The aim of the study is to present the psychological peculiarities of fear of natural darkness (e.g., Li et al., 2015; Morris and Kratochwill, 1998; Mooney et al., 1985) and to provide pedagogical opportunities to reduce it. Alternative types of education presented by the study based on scientific literature include astronomy education, games and tasks in the dark, night camp programs, education with virtual reality. Within each type, different educational options were presented (e.g., star counting, play therapy methods in the dark, night trips, test of courage). In addition, the results of interviews carried out with instructors related to the above mentioned pedagogical methods are also presented, as well as a detailed collection of links to help access several educational materials. The study provides a novel approach to tackling the problem of light pollution, for which it provides abundant and effective educational materials.

Peculiarities of the environmental light pollution in Chernivtsi Region

Introduction. Every year industrial development and economic growth make light pollution worsen on a global scale. It is a well-known fact that artificial outdoor lighting causes destruction of wildlife habitat, impacts circadian rhythms of all living beings, disrupts animal behavior and leads to medical disorders of humans. Over the last decade scientists switched their focus from artificial sky glow over large cities to light pollution of rural landscapes, protected areas and roadways. 
 The purpose of this paper consists in assessing night-time light emissions over Chernivtsi Region as well as over city of Chernivtsi using satellite measurements.
 Methods. Measurements of night-time light emissions were obtained with the help of GIS web application Radiance Light Trends and the light trends analysis tool. The application allows examination of changes in light pollution across selected areas since 1992 and performs time-series analysis with fitting an exponential curve into the data set.
 Results. The trend in light emissions observed by satellites for Chernivtsi Region indicated brightening at the rate of 2.45 % per year from 1992 to 2014, and 2.93 % per year from 2014 to 2021. The marked increase in the intensity of atmospheric light pollution over Chernivtsi Region is largely attributable to urban expansion of district centers, national & international routes and resort complexes. At the same time, the spatial pattern of the light environment over city of Chernivtsi indicated a nearly constant level of aggregate annual light radiance for the last 8 years. A large irregularly shaped "light spot" was detected on the territory of the Prut-Siret interfluve. It crosses the region from the northwest to the southeast and covers the regional center with its suburbs and the national highway H-10. The night light radiance constitutes 47.49∙10-9 mW/cm2 sr in the center of the spot and more than 1∙10-9 mW/cm2 sr at its edges. The highest level of light pollution in Chernivtsi Region was registered in January, and the lowest – in March. Night-time light emission over two most illuminated highways remains relatively constant regardless of the season.
 Conclusion. The study highlights that despite low population and low economic activity, rural landscapes demonstrate a trend towards increasing brightness of the night sky. The findings provide a quantitative reference for light pollution management in the region and for further research in the area.

Ecological risk assessment of heavy metals in farmland soils in Beijing by three improved risk assessment methods.

Beijing, as the capital of China, still has soil pollution problems that cannot be ignored. However, there are few studies on the overall ecological risks of heavy metals in farmland soils in Beijing. This study selected 432 soils and crops heavy metal content data of eight districts in Beijing from academic papers and academic journal papers. In this study, the improved Hakanson method, improved analytic hierarchy process (AHP), and integrated quality impact index (IICQ) comprehensively were used to evaluate the impact of Pb, As, and Cd pollution on the farmland soil environment, and the applicable conditions of these methods were discussed. The results by improved Hakanson method showed that both Pb and As were at the normal ecological risk level, while Cd was the largest contributor to potential ecological risk which accounted for 72.54% of the total risk and is mainly at a moderate ecological risk level. The analysis by improved AHP showed that the average comprehensive index of soil heavy metal pollution in the study area was 0.2317, which was at a light pollution level. The IICQ of soil and agricultural products were between 0 and 1 demonstrating that the soil was clean. In summary, the pollution of heavy metals Pb, As, and Cd in the study area is at a relatively low level, and there is no significant risk to the surrounding environment and human health. IICQ method is suitable for the evaluation of soil heavy metal composition and individual impact and can be more accurately used for the overall ecological evaluation of soil-crop-human health system.

Impact of light pollution on moth morphology–A 137-year study in Germany

Increasing artificial illumination during night has multifaceted effects on species. Moths are shown to be distracted and attracted by artificial light sources, leading to increased mortality through predation or exhaustion. Increased mortality can be expected to increase selection pressure on morphology, particularly those being functional in light detection and flight ability. We were thus interested if intraspecific traits differ between areas and times with differing light pollution values. We chose the moth Agrotis exclamationis, a common species in the Berlin-Brandenburg region, Germany, a region that offers very different levels of light pollution across space and time. We examined body length, eye size and forewing length, traits likely targeted through selection due to light pollution. We examined moths collected over the past 137 years. We predicted decreasing forewing length, body and eye size, in response to increasing light pollution and expected to see trait changes from the past to today, and from rural to urban areas, representing temporal and spatial gradients of increasing light pollution. In order to determine current levels of light pollution, we used radiance values of the years 2012 to 2019. These values were the base to extrapolate previous radiance values for all sample sites and years. We observed no trait differences along the spatial gradient, but trait and sex dependant changes along the temporal gradient. We could not confirm a direct causal link between changes in body size and female eye size. However, we revealed indirect effects of light pollution, and assume habitat fragmentation and host-plants to be the main drivers for these effects. A trend towards smaller-eyed females in ‘medium’ and ‘high’ light-polluted areas over time could be a first indication that morphological trait changes to light pollution are taking place.

Ecological impacts of the LED-streetlight retrofit on insectivorous bats in Singapore.

Cities around the world are transitioning to more efficient lighting schemes, especially retrofitting traditional, high-pressure sodium (HPS) streetlights with light-emitting diode (LED) lights. Although these initiatives aim to address the problems of urban sustainability and save money, the ecological impacts of these retrofits remain poorly understood, especially in brightly lit cities and in the tropics, where urbanisation is most rapid. We performed an experimental study of the retrofit in Singapore–focusing on insectivorous bats, whose activity we monitored acoustically along paired control (HPS-lit) and treatment (LED-lit) streets. We recorded seven species along these streets, but only obtained enough recordings to measure the effect of light type for three of them–all of which can reasonably be described as urban adapters. The strongest predictor of bat activity (an index of habitat use) was rainfall–it has a positive effect. Light type did not influence bat activity or species composition of the bat assemblage along these streets, though it did interact with the effects of rainfall and traffic noise for one bat species. Ultimately, the retrofit may be ecologically meaningless to urban-adapted, tropical insectivores that already experience high levels of light pollution as they do in Singapore. However, while our findings may appear reassuring to those concerned with such retrofits in other tropical and/or brightly-lit cities, they also highlight the contextual nature of ecological impacts. We point out that they should not be prematurely generalised to other locales and systems. In particular, they do not imply no impact on species that are less urban-adapted, and there is a clear need for further studies, for example, on responses of other foraging guilds and of bats (and insects) throughout the tropics.