Light Pollution Research Articles

Source apportionment and risk assessment of heavy metals in typical greenhouse vegetable soils in Shenyang, China.

In this study, the concentrations of Cr, Cu, Ni, Pb, Zn, Cd, As, and Hg in the typical greenhouse vegetable soils in Shenyang, Northeast of China, were determined, and the pollution characteristics and primary sources of heavy mental pollution in soil were analyzed. Results showed that the sum of the mean values of eight typical heavy metals in the soil of the greenhouse soils was 219.79 mg/kg. According to the "Chinese Environmental Quality Evaluation Standard for Farmland of Greenhouse Vegetables Production" (HJ/T 333-2006), the concentrations of Cu (33.50 ± 11.99 mg/kg), Cd (0.246 ± 0.156 mg/kg), and Hg (0.214 ± 0.177 mg/kg) exceeded the limit values in 14.29%, 39.29%, and 39.29% of sampling points, respectively. The single factor pollution index and the Nemerow comprehensive pollution index of heavy metal elements showed that most greenhouse soils were at safety, alert, or light pollution levels. The potential ecological risk index (RI = 505.19) showed that 42.86% of the samples were at high or very high risk and Cd and Hg were the main ecological risk factors. Based on the result of correlation analysis, the Positive Matrix Factorization (PMF) differentiated sources of heavy metal pollution in the study area into four components, including fertilizer input, soil parent material, pesticide spraying and raw coal combustion, and plastic film mulching, which accounted for 36.76%, 22.64%, 20.89%, and 19.71%, respectively, of the total sources of heavy metals.

Identification of illumination source types using nighttime light images from SDGSAT-1

ABSTRACT The constant need for decarbonization has led to the replacement of artificial light at night (ALAN) with light-emitting diodes (LEDs), inducing blue light pollution and its consequent adverse effects. As a result, there is an urgent need for the development of a technique for the rapid, accurate, and large-scale discrimination of the various illumination sources. The newly launched Sustainable Development Science Satellite-1 (SDGSAT-1) can play this role by supplementing the existing nighttime light data with multispectral and high-resolution features. Along these lines, in this work, a novel approach to identify various types of illumination sources using machine learning in SDGSAT-1 images was proposed, taking Beijing as a worked example. The results indicate that: (1) The method can effectively distinguish the various types of light sources with an overall accuracy of 0.92 for ALAN and 0.95 for streetlights. (2) The illumination patterns can be clearly depicted, indicating distinct spatial heterogeneity in ALAN along Beijing’s 5th Ring Road. (3) Statistically significant disparities between road classes and streetlight types were detected, with a notable increase in LED streetlight usage as the road class diminishes. This work emphasizes the crucial role of SDGSAT-1 in analysing ALAN, providing valuable insights in urban lighting management.

The effect of light pollution and noise pollution on birds

It is common knowledge that human society is developing faster and faster nowadays. As human society is developing, the cities are expanding. As the cities are expanding, more and more people are now in the city. To help these people live a better life, more and more resources are produced. After producing most of the products nowadays, there comes pollution. In this way, pollution is getting more and more serious. All of the pollution that is already in a city do not only affect human but also affect birds. One of the most common non pollution is air pollution, almost every city in the world has air pollution. But there are also two other kinds of pollution that is also harming the society and the animals in a serious way. They are light pollution and sound pollution. This passage focuses on these two types of pollution. Light pollution will cause birds to sleep less and may affect their migration way. The birds may be killed halfway on migration way because of the light may lead them to a loss of direction. Sound pollution also reduces the bird sleeping quality. This kind of pollution also cause birds to get food more difficult. By analyzing the effects of these pollution, some ways to help birds may be figured out.

Molecular mechanisms of artificial light at night affecting circadian rhythm disturbance.

Artificial light at night (ALAN) pollution has been regarded as a global environmental concern. More than 80% of the global population is exposed to light pollution. Exacerbating this issue, artificially lit outdoor areas are growing by 2.2% per year, while continuously lit areas have brightened by 2.2% each year due to rapid population growth and expanding urbanization. Furthermore, the increasing prevalence of night shift work and smart device usage contributes to the inescapable influence of ALAN. Studies have shown that ALAN can disrupt endogenous biological clocks, resulting in a disturbance of the circadian rhythm, which ultimately affects various physiological functions. Up until now, scholars have studied various disease mechanisms caused by ALAN that may be related to the response of the circadian system to light. This review outlines the molecular mechanisms by which ALAN causes circadian rhythm abnormalities in sleep disorders, endocrine diseases, cardiovascular disease, cancer, immune impairment, depression, anxiety and cognitive impairments.

Penentuan Status Mutu Air Sungai Wrati Pasuruan Jawa Timur dengan Indeks Kualitas Air

The Wrati River is located in Pasuruan Regency. This river crosses three sub-districts and six sub-districts, with a total distance of 13.6 kilometers. The subdistrict through which this river passes has land use for household, agricultural, and industrial purposes. These activities hurt rivers, causing pollution and decreasing water quality. Determining water quality status is very important to understand the suitability of river water for various purposes. Understanding water quality can be fundamental information for managing and preventing river pollution. The pollutant index approach used in this research refers to the guidelines in the Decree of the Minister of the Environment Number 115 of 2003. The research results show that the water quality of the Wrati River from upstream to downstream is included in the lightly polluted category at each sampling point, with an index value of 4.94. The main factor causing light pollution in Wrati River water is the excessive phosphate content and other parameters that exceed the specified quality standards. Based on the findings of this research, waste management efforts need to be made to improve the quality of this river water.

Blue light at night produces stress-evoked heightened aggression by enhancing brain-derived neurotrophic factor in the basolateral amygdala

Light is an underappreciated mood manipulator. People are often exposed to electronic equipment, which results in nocturnal blue light exposure in modern society. Light pollution drastically shortens the night phase of the circadian rhythm. Preclinical and clinical studies have reported that nocturnal light exposure can influence mood, such as depressive-like phenotypes. However, the effects of blue light at night (BLAN) on other moods and how it alters mood remain unclear. Here, we explored the impact of BLAN on stress-provoked aggression in male Sprague‒Dawley rats, focusing on its influence on basolateral amygdala (BLA) activity. Resident-intruder tests, extracellular electrophysiological recordings, and enzyme-linked immunosorbent assays were performed. The results indicated that BLAN produces stress-induced heightened aggressive and anxiety-like phenotypes. Moreover, BLAN not only potentiates long-term potentiation and long-term depression in the BLA but also results in stress-induced elevation of brain-derived neurotrophic factor (BDNF), mature BDNF, and phosphorylation of tyrosine receptor kinase B expression in the BLA. Intra-BLA microinfusion of BDNF RNAi, BDNF neutralizing antibody, K252a, and rapamycin blocked stress-induced heightened aggressive behavior in BLAN rats. In addition, intra-BLA application of BDNF and 7,8-DHF caused stress-induced heightened aggressive behavior in naïve rats. Collectively, these results suggest that BLAN results in stress-evoked heightened aggressive phenotypes, which may work by enhancing BLA BDNF signaling and synaptic plasticity. This study reveals that nocturnal blue light exposure may have an impact on stress-provoked aggression. Moreover, this study provides novel insights into the BLA BDNF-dependent mechanism underlying the impact of the BLAN on mood.

Living on the edge: urban fireflies (Coleoptera, Lampyridae) in Morelia, Michoacán, Mexico.

Fireflies (Coleoptera, Lampyridae) are a globally threatened group of insects due to habitat loss and fragmentation, light pollution, climate change and pesticides. However, against all odds, some firefly populations persist in urbanized environments where all four of these factors are present simultaneously. In this work, we compiled several data sources to document the diversity of fireflies in the urbanized area of Morelia, characterize their current habitats, and determine the main stressors affecting these bioluminescent insects. We found seven genera and 26 species of fireflies (19 nocturnal, seven diurnal) associated with 32 urban, peri-urban and extra-urban areas; at least, 14 are new records for Michoacán, and the list for the state now includes nine genera and 41 species. Five additional sites were documented as extinction sites. We compared the characteristics of these five sites with those of the sites with extant populations. We found that in Morelia, fireflies are mainly associated with areas that have high to moderate proportions of vegetation cover, are near water bodies, have very gentle to moderate slopes, and are exposed to low levels of light pollution. In contrast, the extinction sites showed high proportions of artificial surfaces and high levels of light pollution. Because some fireflies are considered bioindicators of ecosystem integrity as they are associated to specific habitats, are highly diverse and due to their sensitivity to environmental changes, we consider that sites from Morelia's urban core and extinction sites show the highest levels of environmental degradation, threatening most fireflies and other insects living in the urban core with local extinction. At the same time, our results also suggest that implementing conservation strategies and sustainable planning for the urban development of Morelia in the short term could allow fireflies and other vital elements of the city's insect communities to persist for future generations. Restoration and conservation of green areas and nighttime environments are essential for biodiversity and human health, especially in intra-urban zones.

An environmental analysis of public UAP sightings and sky view potential

Sightings of unidentified flying objects (UFOs) or unidentified anomalous phenomena (UAP) have been reported throughout history. Given the potential security and safety risks they pose, as well as scientific curiosity, there is increasing interest in understanding what these sighting reports represent. We approach this problem as an important one of the human experience and that can be examined through a geographical lens: what local factors may increase or decrease the number of sighting reports? Using a Bayesian regression method, we test hypotheses based on variables representing sky view potential (light pollution, tree canopy, and cloud cover) and the potential for objects to be present in the sky (aircraft and military installations). The dependent variable includes over 98,000 publicly reported UAP sightings in the conterminous United States during the 20-year period from 2001 to 2020. The model results find credible correlations between variables that suggest people see more “phenomena” when they have more opportunity to. This analysis is one of few investigations of UAP sighting reports at a national scale providing context to help examine individual reports. Given that these objects are labeled unidentifiable in the personal sense, there are many natural and/or human based explanations worth exploring.

Quantification of Light Pollution Levels Based on Principal Component Analysis and Hierarchical Analysis Approach

The level of light pollution risk is influenced by a number of factors. In this paper, we established a model to evaluate the risk level of light pollution in a certain area by considering various factors.Through the principal component analysis of the 12 indicators selected by us, three principal components are extracted, and then the analytic hierarchy process is used to evaluate the three principal components, so as to establish the corresponding weight of the three principal components, and finally establish the relevant evaluation function.

Artificial night‐time lighting and nutrient enrichment synergistically favour the growth of alien ornamental plant species over co‐occurring native plants

Abstract Insights into ecological drivers of alien plant invasions can be gained through comparative studies of growth and fecundity of invasive alien plants versus those of co‐occurring non‐invasive alien plants and native plants across environmental conditions in common garden settings. Habitats that harbour alien plant species in many ecosystems globally are presently experiencing light pollution resulting from artificial light at night (ALAN) and increased rates of nutrient enrichment of the soil. However, the potential interactive effects of ALAN and nutrient enrichment on invasiveness of alien plant species remain unknown. Here, we performed a common‐garden experiment to test the interactive effects of ALAN and soil nutrient enrichment on the growth of a random set of ten alien (five invasive and five non‐invasive naturalized) and seven co‐occurring native ornamental plant species that are commonly cultivated within urban and peri‐urban areas of Nairobi city in Kenya. We predicted that a simultaneous increase in photoperiod via ALAN and nutrient enrichment will favour growth of invasive alien plant species over that of non‐invasive alien and native plant species. We grew the 17 plant species under natural daylight (ALAN−) versus natural daylight followed by ALAN (ALAN+) and fully crossed with two levels of nutrient enrichment (low vs. high) and competition (competition vs. no‐competition against a native plant Ocimum gratissimum) treatments. Under simultaneous high‐nutrient and no‐competition treatments, ALAN enhanced mean total biomass of invasive and non‐invasive naturalized alien species by 61.1% and 131.4%, respectively but decreased that of native plant species by 34%. In contrast, under simultaneous high‐nutrient and competition treatments, ALAN enhanced mean total biomass of invasive alien plant species by 68.6% and that of non‐invasive naturalized alien species by 51.9% and native species by 35.4%. High‐nutrient treatment enhanced flower formation more strongly in invasive and non‐invasive naturalized alien plants than in native plants. The invasive and non‐invasive naturalized alien species grew taller than native species across the light, nutrient, and competition treatments. Synthesis: The present findings suggest that light pollution and nutrient enrichment may jointly confer growth advantage to invasive alien plant species over that of co‐occurring native plant species and enhance invasiveness of alien plant species.

Does a flashing artificial light have more or conversely less impacts on animals than a continuous one? A systematic review

Background: Light pollution has been increasingly recognised as a threat to biodiversity, especially with the current expansion of public lighting. Although the impacts of light intensity, spectral composition and temporality are more often studied, another component of light, its flicker frequency, has been largely overlooked. However, flashing light could also have impacts on biodiversity, and especially on animal behaviour and physiology. Objective: This systematic review aimed at identifying the reported physiological and behavioural impacts of flashing light on animals when compared to continuous light. Methods: We followed the standards recommended by the Collaboration for Environmental Evidence (CEE) in order to achieve a comprehensive, transparent and replicable systematic review. Citations were primarily extracted from three literature databases and were then screened for relevance successively on their titles, abstracts and full-texts. Retained studies were finally critically appraised to assess their validity and all relevant data were extracted. Only studies which compared a flashing light to a continuous one were included. Results: At first, we found 19,730 citations. Screening and critical appraisal resulted in 32 accepted articles corresponding to 54 accepted observations—one observation corresponding to one species and one outcome. We collated data on four main taxa: Aves (the most studied one), Actinopterygii, Insecta and Mammalia as well as on plankton. Conclusions: The impacts of flashing light are currently critically understudied and varied between species and many light specificities (e.g. frequency, wavelength, intensity). Therefore, no definitive conclusions could be drawn for now. Thus, research on flashing light should be pressingly carried out in order to better mitigate the impacts of Artificial Light at Night (ALAN) on wildlife. In the meantime, we would recommend precautionary principles to be applied: flashing lighting should be limited when not deemed essential and flicker frequencies managed to prevent animals from experiencing any potential harm from flashing light.

Efficient Visualization of Light Pollution for the Night Sky

Artificial light sources make our daily life convenient, but cause a severe problem called light pollution. We propose a novel system for efficient visualization of light pollution in the night sky. Numerous methods have been proposed for rendering the sky, but most of these focus on rendering of the daytime or the sunset sky where the sun is the only, or dominant light source. For the visualization of the light pollution, however, we must consider many city light sources on the ground, resulting in excessive computational cost. We address this problem by precomputing a set of intensity distributions for the sky illuminated by city light at various locations and with different atmospheric conditions. We apply a principal component analysis and fast Fourier transform to the precomputed distributions, allowing us to efficiently visualize the extent of the light pollution. Using this method, we can achieve one to two orders of magnitudes faster computation compared to a naive approach that simply accumulates the scattered intensity for each viewing ray. Furthermore, the fast computation allows us to interactively solve the inverse problem that determines the city light intensity needed to reduce light pollution. Our system provides the user with both a forward and inverse investigation tool for the study and minimization of light pollution.

Sustainable mindsets: Combining traditional indigenous knowledge with non-aboriginal understanding to address environmental risks

Aboriginal and Torres Strait Islander peoples are the traditional owners of Australia. It has been predicted that they have been the custodians of these lands for at least 60,000 years. Their traditional lands are inextricably linked to their languages, cultural practices and spiritual being. As the custodians they have used their traditional Indigenous knowledge to care for the land – its plants, animals and waterways, protecting unique ecosystems and maintaining sustainability. In fact, their traditional understanding reflects what has been described in the literature as a sustainable mindset. We come together as non-Aboriginal and Aboriginal educators to explore how environmental threats within the epoc of Anthropocene may be addressed using such a sustainable mindset – one reflecting both indigeneity and posthumanism perspectives. We describe three case studies showing how the use of traditional knowledge held by local Indigenous communities (IPLCs) can be used with non-Indigenous knowledge to address human induced planetary changes to protect important animal species and the land on which they live. We draw on written and oral reports from our Indigenous co-authors and data obtained informally from them by way of ‘yarning’. We describe how in the north-west of Western Australia areas of significant ecological and cultural value are being negatively affected by human-induced change threatening different animal species and ecosystems. We outline the effects of light pollution in Port Hedland and how this is disrupting the life cycle of the flatback sea turtle - culturally significant sea animals. As a point of comparison, we next describe how green back turtle and Dugong populations are being protected and sustained on the Dampier Peninsula using traditional knowledge more recently supplemented through the work of the Bardi Jawi Rangers. Finally, we examine how the Fitzroy River catchment area is increasingly under threat from water extraction and mining, but how a sustainable mindset can be used to obviate these environmental risks.

Investigation of the Effect of Light Pollution on Quality of Urban Life: The Case of Iskenderun/Hatay

Işık, günümüzde ihtiyaç duyduğumuz en önemli kaynaklardan olmasına karşın, gereğinden fazla kullanımının yarattığı etkilerle en önemli kirlilik kaynaklarından biri haline gelmiştir. Işık kirliliği insan, hayvan ve bitki sağlığı üzerinde ciddi etkilere sahiptir. Bu etkilerin yanında, enerji tüketiminin de büyük bir kısmı yanlış aydınlatma tercihlerinden kaynaklanmaktadır. Işık kirliliği, ihtiyaç duyulan alanda yeterli sayıda ve parlaklıkta aydınlatma biriminin tercih edilmesiyle kontrol edilebilir. Dünya nüfusunun üçte ikisi yoğun yapay ışıkla kirlenmiş kıyı yerleşimlerinde yaşamaktadır. 
 Bu çalışmanın amacı Türkiye’nin önemli bir kıyı yerleşimi olan İskenderun ilçe merkezi ve yakın çevresindeki ışık kirliliğinin kontrolünü sağlamaktır. Bu kapsamda Gökyüzü Kalitesi Ölçer (SQM-LU) cihazıyla 1x1 km’lik gridlerin merkez noktalarında ölçümler alınmış ve IDW yöntemi ile Bortle ölçeğine göre ışık kirliliği dağılım haritası oluşturulmuştur. Bu değerlendirme sonucunda çalışma alanının %..’lik bölümü Bortle ölçeğine göre 6 ve 7. düzey alanlar, %...’lik bölümü ise 8 ve 9. düzey alanlar olarak belirlenmiştir. Sonuç olarak yüksek oranda ışık kirliliğinin tespit edildiği İskenderun ilçe merkezi ve yakın çevresinde daha nitelikli bir yaşam kalitesi için tercih edilmesi gerek aydınlatma elemanları ve geliştirilmesi gereken stratejiler sunulmuştur.

Artificial light at night impacts night-time activity but not day-time behaviour in a diurnal coral reef fish

An important, yet overlooked form of anthropogenic pollution is sensory pollution, and one of the most pervasive forms of sensory pollution is artificial light at night (ALAN). Despite the growing use of ALAN across the globe, limited research has examined the impacts of ALAN on coral reef fish. This study aims to further our understanding of the behavioural impacts of light pollution on fish by exposing the humbug damselfish (Dascyllus aruanus) to ALAN (∼15–25 lux, white LED light) over a period of 14 days, in situ. We assessed nocturnal activity, and diurnal shelter use and emergence time following a simulated threat in natural (control) and ALAN conditions. D. aruanus colonies exposed to ALAN were active at night and were lacking cryptic colouration observed in control fish, however this altered nocturnal activity did not appear to impact the diurnal behaviours we measured. Our findings provide critical insight into the impact of ALAN exposure to nocturnal behaviour of a diurnal fish and highlight the potential for increased risk of nocturnal predation under ALAN. Further studies with a longer ALAN exposure time will help illuminate the extent of behavioural changes and implications caused by ALAN in shallow coral reef systems.

STATUS MUTU AIR DAERAH ALIRAN SUNGAI DI KABUPATEN BERAU PROVINSI KALIMANTAN TIMUR

The watershed in Berau Regency is used as an economic route and means of transportation of goods from mining, plantations, and agriculture as well as a source of raw materials for making drinking water. the water quality of the Berau watershed based on the value of the River Water Pollution Index in Berau Regency includes light pollution. This is a concern to conduct research in the Berau watershed, where this study aims to analyze the status of water quality according to the IP (Pollution Index) method and the economic value of watersheds in Berau Regency for the people of Berau Regency and compile recommendations for pollution control and watershed utilization in Berau Regency.The calculation uses the Pollution Index (IP) method of watershed quality status in Berau Regency consisting of Segah River, Kelay River, and Sungi Berau is in Light Pollution condition with a value of (1.75 ≤ IP ≤ 4.97) with a tendency for Berau River to have a greater pollution burden.

Development and testing of the Night Sky Connectedness Index (NSCI)

Whilst there is a growing interest in people's relationship with the natural world, much of the literature in this area tends to focus on daytime behaviour. There is far less research that attempts to understand the importance of people's relationship to natural environments at night and particularly towards the night sky. Therefore, the purpose of this study was to design, develop and validate a new measure - the Night Sky Connectedness Index (NSCI). The items of the NSCI were created and based on relevant theory, similar types of measures, and stakeholder consultation – for both the generation and selection of items. The psychometric properties were assessed using a sample of 406 people from the general population – with any level of interest in the night sky - and of these 115 completed a test-retest follow-up survey. Exploratory Factor Analysis and reliability testing resulted in a 12-item measure with two subscales: Connection to, and Protection of the night sky. The NSCI demonstrated good to excellent internal consistency for the overall scale and for each of its subscales and shows strong test-retest reliability. There was also strong evidence for the scale's convergent, discriminant and construct validity. In addition, the findings indicated that a greater connection to the night sky was significantly and positively related to a person's mental health and happiness. Our research also suggests that those people who live in more light-polluted areas are less connected to the night sky and feel less likely to protect it. The NSCI may be useful when, (i) investigating pro-environmental and conservation behaviour, (ii) assessing the efficacy of strategies or interventions aimed at reducing light pollution, (iii) helping to restore the human-night sky relationship, (iv) informing policy and responsible lighting use, and (v) rewilding our night skies to protect our natural environment and cultural heritage.

Artificial light affects foraging behavior of a synanthropic bat.

Artificial light at night has been considered an emerging threat to global biodiversity. However, the impacts of artificial light on foraging behavior in most wild animals remain largely unclear. Here, we aimed to assess whether artificial light affects foraging behavior in Asian parti-colored bats (Vespertilio sinensis). We manipulated the spectra of light-emitting diode (LED) lighting in a laboratory. Using video and audio recording, we monitored foraging onset, total foraging time, food consumption, freezing behavior (temporary cessation of body movement), and echolocation vocalizations in triads of bats under each lighting condition. Analyses showed that the foraging activities of experimental bats were reduced under LED light. Green, yellow, and red light had greater negative effects on bats' foraging onset, total foraging time, and food consumption than white and blue light. LED light of different spectra induced increased freezing time and echolocation vocalizations in captive bats, except for the white light. The peak wavelength of light emission correlated positively with freezing time, estimated echolocation pulse rate (the number of echolocation pulses per minute), and foraging onset, but negatively with total foraging time and food consumption. These results demonstrate that artificial light disturbs foraging behavior in Asian parti-colored bats. Our findings have implications for understanding the influencing mechanism of light pollution on bat foraging.

Towards future challenges in the measurement and modelling of night sky brightness

ABSTRACTIn ground-based astronomy, the brightness of the night sky is the limiting factor that determines the efficacy of any particular telescope in terms of detecting faint objects. Proper measurement and monitoring of night sky brightness (NSB) is therefore key to protecting sites of astronomical observatories from light pollution and maximizing their scientific productivity. However, current data sources and modelling approaches exhibit practical shortcomings that significantly limit their utility. By considering the current situation in measuring light pollution, we identify opportunities for improvements. These include defaulting to spatially resolved sky brightness measurements, routinely incorporating spectral information and polarization, and collecting simultaneous meteorological data. Given the acute threat to astronomy posed by rapidly increasing NSB around the world, we argue that the time has come for the standardization of NSB measurement and monitoring methods and protocols.

Review of recent advances in photosensitive polymer materials and requirements for transmission diffractive optical elements for LED light sources

Scattered light from outdoor LED sources is a major contributor to blue-spectrum light pollution which negatively impacts ecology and public health. Volume holographic diffractive optical elements (DOEs), made with low-cost photosensitive polymers, are proposed as a technological solution that can minimise this scattering. This review examines requirements needed for efficient operation of transmission-format DOEs with LEDs and implications for material choices. For such DOEs to have a single diffraction order and high efficiency there is a corresponding range of acceptable Δn. A survey of materials also found that many current materials satisfy the Δn requirements for single-element DOEs. It is proposed that future efforts focus on robustness, environmental sustainability, scalability, multiplexing, optical quality, and reduced cost.