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Background: Artificial light at night (ALAN) is a common phenomenon and contributes to the severe light pollution suffered by more than 80% of the world's population. This study aimed to evaluate the relationship between outdoor ALAN exposure and cardiovascular health (CVH) in patients with diabetes and the influence of various modifiable factors., Methods: A survey method based on the China Diabetes and Risk Factor Monitoring System was adopted. Study data were extracted for 1765 individuals with diabetes in Anhui Province. Outdoor ALAN exposure (nW/cm 2 /sr) within 1000 m of each participant's residential address was obtained from satellite imagery data, with a resolution of ~1000 m. Health risk behaviors (HRBs) were measured via a standardized questionnaire. A linear regression model was employed to estimate the relationship between outdoor ALAN, HRBs, and CVH., Results: Participants' mean age was 59.10 ± 10.0 years. An association was observed between ALAN and CVH in patients with diabetes (β = 0.205) and exercise (β = -1.557), moderated by HRBs, or metabolic metrics. There was an association between ALAN, ALAN, vegetable intake, and CVH., Conclusions: Exploring the relationship between ALAN exposure and cardiovascular and metabolic health provides policy data for improving light pollution strategies and reducing the risk of cardiovascular and metabolic disease in patients with diabetes., (© 2024 The Author(s). Journal of Diabetes published by Ruijin Hospital, Shanghai Jiaotong University School of Medicine and John Wiley & Sons Australia, Ltd.)

Background: Recent evidences highlight the potential impact of outdoor Light at Night (LAN) on executive function. However, few studies have investigated the association between outdoor LAN exposure and executive function., Methods: We employed data from 48,502 Chinese children aged 5-12 years in a cross-sectional study conducted in Guangdong province during 2020-2021, to examine the association between outdoor LAN and executive function assessed using the validated parent-completed Behavior Rating Inventory of Executive Function. We assessed children's outdoor LAN exposure using the night-time satellite images based on the residential addresses. We used generalized linear mixed models to estimate the association between outdoor LAN exposure and executive function scores and executive dysfunction., Results: After adjusting for potential covariates, higher quintiles of outdoor LAN exposure were associated with poorer executive function. Compared to the lowest quintile (Q1), all higher quintiles of exposure showed a significant increased global executive composite (GEC) score with β (95% confidence intervals, CI) of 0.58 (0.28, 0.88) in Q2, 0.59 (0.28, 0.9) in Q3, 0.85 (0.54, 1.16) in Q4, and 0.76 (0.43, 1.09) in Q5. Higher quintiles of exposure were also associated with higher risks for GEC dysfunction with odd ratios (ORs) (95% CI) of 1.34 (1.18, 1.52) in Q2, 1.40 (1.24, 1.59) in Q3, 1.40 (1.23, 1.59) in Q4, and 1.39 (1.22, 1.58) in Q5. And stronger associations were observed in children aged 10-12 years., Conclusions: Our study suggested that high outdoor LAN exposure was associated with poor executive function in children. These findings suggested that future studies should determine whether interventions to reduce outdoor LAN exposure can have a positive effect on executive function., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

The widespread and pervasive use of artificial light at night (ALAN) in our modern 24-hour society has emerged as a substantial disruptor of natural circadian rhythms, potentially leading to a rise in unhealthy lifestyle-related behaviors (e.g., poor sleep; shift work). This phenomenon has been associated with an increased risk of type 2 diabetes mellitus (T2DM), which is a pressing global public health concern. However, to date, reviews summarizing associations between ALAN and T2DM have primarily focused on the limited characteristics of exposure (e.g., intensity) to ALAN. This literature review extends beyond prior reviews by consolidating recent studies from 2000 to 2024 regarding associations between both indoor and outdoor ALAN exposure and the incidence or prevalence of T2DM. We also described potential biological mechanisms through which ALAN modulates glucose metabolism. Furthermore, we outlined knowledge gaps and investigated how various ALAN characteristics beyond only light intensity (including light type, timing, duration, wavelength, and individual sensitivity) influence T2DM risk. Recognizing the detrimental impact of ALAN on sleep health and the behavioral correlates of physical activity and dietary patterns, we additionally summarized studies investigating the potential mediating role of each component in the relationship between ALAN and glucose metabolism. Lastly, we proposed implications of chronotherapies and chrononutrition for diabetes management in the context of ALAN exposure.

Artificial light at night (ALAN) is an increasingly pervasive pollutant that alters animal behaviour and physiology, with cascading impacts on development and survival. Recent evidence links exposure to ALAN with neural damage, potentially due to its action on melatonin synthesis, a powerful antioxidant. However, these data are scarce and taxonomically limited. Here, we used micro-CT to test the effects of short-term ALAN exposure on brain volumes in the Australian garden orb-weaving spider ( Hortophora biapicata ), a species commonly found in urban areas and, specifically, around street lights. We found that short-term ALAN exposure was linked to reductions in the volumes of brain structures in the primary eye visual pathway, potentially as a consequence of oxidative stress or plastic shifts in neural investment. Although the effects of ALAN were subtle, they provided new insights into potential mechanisms underpinning the behavioural and physiological impacts of ALAN in this important urban predator.

Background: Exposure to light at night (LAN) has been associated with multiple adverse health outcomes. However, evidence is limited regarding the impacts of LAN exposure on human inflammation., Objectives: To examine the association between real-ambient bedroom LAN exposure with systemic inflammation and circadian rhythm of inflammatory markers., Methods: Using data from a prospective cohort study of Chinese young adults. At baseline, bedroom LAN exposure was measured with a portable illuminance meter; fasting blood sample for high-sensitivity C-reactive protein (hs-CRP) assay was collected. At 3-year follow-up, 20 healthy young adults (10 LAN avg < 5 lx, 10 LAN avg ≥ 5 lx) were recruited from the same cohort; time-series venous blood samples were sampled every 4 h over a 24 h-cycle for the detection of 8 inflammatory markers. Circadian rhythm of inflammatory markers was assessed using cosinor analysis., Results: At baseline, the average age of the 276 participants was 18.7 years, and 33.3 % were male. Higher levels of bedroom LAN exposure were significantly associated with increased hs-CRP levels. The association between bedroom LAN exposure and systemic inflammation was only significant in the inactive group (MVPA < 2 h/d) but not in the physically active group (MVPA ≥ 2 h/d). In addition, exposure to higher levels of nighttime light (LAN avg ≥ 5 lx) disrupted circadian rhythms (including rhythmic expression, circadian amplitude and circadian phase) of some inflammatory cytokines and inflammatory balance indicators., Conclusion: Exposure to bedroom nighttime light increases systemic inflammation and disrupts circadian rhythm of inflammatory markers. Keep bedroom darkness at night may represent important strategies for the prevention of chronic inflammation. Additionally, for people living a community with higher nighttime light pollution, regular physical activity may be a viable option to counteract the negative impacts of LAN exposure on chronic inflammation., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper, (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Natural experiments provide remarkable opportunities to test the large-scale effects of human activities. Widespread energy blackouts offer such an 'experiment' to test the impacts of artificial light at night (ALAN) on wildlife. We use the situation in South Africa, where regular scheduled blackouts are being implemented, to highlight this opportunity., Competing Interests: Declaration of interests No interests are declared., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Artificial light at night, a well-recognized circadian clock disrupter, causes disturbances in endocrine homeostasis. However, the association of artificial light at night with polycystic ovary syndrome (PCOS) is still unknown. This study examines the effects of outdoor artificial light at night on sex hormones, glucose homeostasis markers, and PCOS prevalence in Anhui Province, China., Methods: We recruited 20,633 women of reproductive age from Anhui Medical University Reproductive Medicine Center. PCOS was diagnosed according to Rotterdam criteria. We estimated long-term (previous year) and short-term (previous month) artificial light at night values for residential addresses using 500 m resolution satellite imagery. We fitted multivariable models, using both linear and logistic regression, to estimate the association of artificial light at night with sex hormones, glucose homeostasis markers, and PCOS prevalence., Results: Both long-term and short-term exposure to outdoor artificial light at night were negatively associated with follicle-stimulating hormone and luteinizing hormone levels, while positively associated with testosterone, fasting insulin, homeostasis model assessment-insulin resistance, and homeostasis model assessment-insulin resistance-β levels. The second-highest quintile of artificial light at night was associated with increased PCOS prevalence (odds ratio [OR long-term ] = 1.4; 95% confidence interval [CI] = 1.2, 1.6 and OR short-term = 1.3; 95% CI = 1.1, 1.5) compared with the lowest quintile. In addition, prevalence of PCOS was linearly associated with long-term exposure to artificial light at night, but nonlinearly associated with short-term exposure. This association was more evident in younger, obese or overweight, moderately educated, rural women, and for the summer and fall seasons., Conclusion: Outdoor artificial light at night may be a novel risk factor for PCOS., Competing Interests: The authors report no conflicts of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Light is the most important Zeitgeber for temporal synchronization in nature. Artificial light at night (ALAN) disrupts the natural light-dark rhythmicity and thus negatively affects animal behavior. However, to date, ALAN research has been mostly conducted under laboratory conditions in this context. Here, we used the field cricket, Gryllus bimaculatus, to investigate the effect of ALAN on insect behavior under semi-natural conditions, i.e., under shaded natural lighting conditions, natural temperature and soundscape. Male crickets were placed individually in outdoor enclosures and exposed to ALAN conditions ranging from <0.01 to 1500 lx intensity. The crickets' stridulation behavior was recorded for 14 consecutive days and nights and their daily activity patterns were analysed. ALAN impaired the crickets' stridulation rhythm, evoking a change in the crickets' naturally synchronized daily activity period. This was manifested by a light-intensity-dependent increase in the proportion of insects demonstrating an intrinsic circadian rhythm (free-run behavior). This also resulted in a change in the population's median activity cycle period. These ALAN-induced effects occurred despite the crickets' exposure to almost natural conditions. Our findings provide further validity to our previous studies on ALAN conducted under lab conditions and establish the deleterious impacts of ALAN on animal behavioral patterns. TEASER: Artificial light at night alters cricket behavior and desynchronizes their stridulation even under near-natural conditions., Competing Interests: Declaration of competing interest The authors declare no competing interests related to this study., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Objective: This study aims to explore the association between outdoor artificial light at night (ALAN) exposure and gestational diabetes mellitus (GDM)., Methods: This study is a retrospective case-control study. According with quantiles, ALAN has been classified into three categories (Q1-Q3). GDM was diagnosed through oral glucose tolerance tests. Conditional logistic regression models were used to evaluate the association between ALAN exposure and GDM risk. The odds ratio (OR) with 95% confidence interval (CI) was used to assess the association. Restricted cubic spline analysis (RCS) was utilized to investigate the no liner association between ALAN and GDM., Results: A total of 5,720 participants were included, comprising 1,430 individuals with GDM and 4,290 matched controls. Pregnant women exposed to higher levels of ALAN during the first trimester exhibited an elevated risk of GDM compared to those with lower exposure levels (Q2 OR = 1.39, 95% CI 1.20-1.63, p  < 0.001); (Q3 OR = 1.70, 95% CI 1.44-2.00, p  < 0.001). Similarly, elevated ALAN exposure during the second trimester also conferred an increased risk of GDM (second trimester: Q2 OR = 1.70, 95% CI 1.45-1.98, p  < 0.001; Q3 OR = 2.08, 95% CI 1.77-2.44, p  < 0.001). RCS showed a nonlinear association between ALAN exposure and GDM risk in second trimester pregnancy, with a threshold value of 4.235., Conclusion: Outdoor ALAN exposure during pregnancy is associated with an increased risk of GDM., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Sun, Ye, Liu, Yang, Hui, Chen, Liu, Guo, Wang, Lv, Tang and Zhang.)

Background: Nowadays artificial light highly increases human exposure to light leading to circadian rhythm and sleep perturbations. Moreover, excessive exposure of ocular structures to photons can induce irreversible retinal damage. Meta-analyses showed that sunlight exposure influences the age of onset and the progression of Age-related macular degeneration (AMD), the leading cause of blindness in people over fifty-year old. Currently, the blue-light hazard (BLH) curve is used in the evaluation of the phototoxicity of a light source for domestic lighting regulations., Objectives: Here, we analyze the phototoxicity threshold in rats and investigate the role played by the light spectrum, assessing the relevance of the use of the BLH-weighting to define phototoxicity., Methods: We exposed albino rats to increasing doses of blue and white light, or to lights of different colors to evaluate the impact of each component of the white light spectrum on phototoxicity. Cellular mechanisms of cell death and cellular stress induced by light were analyzed., Results: Our results show that the phototoxicity threshold currently accepted for rats is overestimated by a factor of 50 when considering blue light and by a factor of 550 concerning white light. This is the result of the toxicity induced by green light that increases white light toxicity by promoting an inflammatory response. The content of green in white light induces 8 fold more invasion of macrophages in the retina than the content of blue light. Moreover, the use of BLH-weighting does not evaluate the amount of red radiations contained in white light that mitigates damage by inhibiting the nuclear translocation of L-DNase II and reducing by 33% the number of TUNEL-positive cells., Discussion: These findings question the current methods to determine the phototoxicity of a light source and show the necessity to take into account the entire emission spectrum. As current human phototoxicity thresholds were estimated with the same methods used for rats, our results suggest that they might need to be reconsidered., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

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., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Importance: Light pollution's impact on human health is increasingly recognized, but its link to exudative age-related macular degeneration (EAMD) remains unclear., Objective: To investigate the association between exposure to outdoor artificial light at night (OALAN) and the risk of incident EAMD., Design, Setting, and Participants: In this nationwide population-based case-control study, all individuals 50 years or older with newly diagnosed EAMD between January 1, 2010, and December 31, 2011, were identified with reference to the Korean National Health Insurance Service registration program database for rare and intractable diseases. Birth year- and sex-matched controls (with no EAMD diagnosis until 2020) were selected at a 1:30 ratio. Data were acquired from May 1 to December 31, 2021, and analyzed from June 1 to November 30, 2022., Exposures: Mean levels of OALAN at participants' residential addresses during 2008 and 2009 were estimated using time-varying satellite data for a composite view of persistent nighttime illumination at an approximate scale of 1 km2., Main Outcomes and Measures: The hazard ratios (HRs) and 95% CIs of the association between residential OALAN and risk of incident EAMD were determined based on maximum likelihood estimation after adjusting for sociodemographic characteristics, comorbidities, and area-level risk factors (ie, nighttime traffic noise and particulate matter of aerodynamic diameter ≤10 μm in each participant's administrative district of residence)., Results: A total of 126 418 participants were included in the analysis (mean [SD] age, 66.0 [7.9] years; 78 244 men [61.9%]). Of these, 4078 were patients with newly diagnosed EAMD and 122 340 were EAMD-free matched controls. In fully adjusted models, an IQR (55.8 nW/cm2/sr) increase in OALAN level was associated with an HR of 1.67 (95% CI, 1.56-1.78) for incident EAMD. The exposure-response curve demonstrated a nonlinear, concave upward slope becoming more pronounced at higher levels of light exposure (ie, at approximately 110 nW/cm2/sr). In a subgroup analysis, an IQR increase in OALAN was associated with increased risk of incident EAMD in urban areas (HR, 1.46 [95% CI, 1.33-1.61]) but not in rural areas (HR, 1.01 [95% CI, 0.84-1.22])., Conclusions and Relevance: In this nationwide population-based case-control study, higher levels of residential OALAN were associated with an increased risk of incident EAMD. Future studies with more detailed information on exposure, individual adaptive behaviors, and potential mediators are warranted.

Collisions between birds and aircraft cause bird mortality, economic damage, and aviation safety hazards. One proposed solution to increasing the distance at which birds detect and move away from an approaching aircraft, ultimately mitigating the probability of collision, is through onboard lighting systems. Lights in vehicles have been shown to lead to earlier reactions in some bird species but they could also generate attraction, potentially increasing the probability of collision. Using information on the visual system of the Canada goose ( Branta canadensis ), we developed light stimuli of high chromatic contrast to their eyes. We then conducted a controlled behavioral experiment ( i.e. , single-choice test) to assess the avoidance or attraction responses of Canada geese to LED lights of different wavelengths (blue, 483 nm; red, 631 nm) and pulsing frequencies (steady, pulsing at 2 Hz). Overall, Canada geese tended to avoid the blue light and move towards the red light; however, these responses depended heavily on light exposure order. At the beginning of the experiment, geese tended to avoid the red light. After further exposure the birds developed an attraction to the red light, consistent with the mere exposure effect. The response to the blue light generally followed a U-shape relationship (avoidance, attraction, avoidance) with increasing number of exposures, again consistent with the mere exposure effect, but followed by the satiation effect. Lights pulsing at 2 Hz enhanced avoidance responses under high ambient light conditions; whereas steady lights enhanced avoidance responses under dim ambient light conditions. Our results have implications for the design of lighting systems aimed at mitigating collisions between birds and human objects. LED lights in the blue portion of the spectrum are good candidates for deterrents and lights in the red portion of the spectrum may be counterproductive given the attraction effects with increasing exposure. Additionally, consideration should be given to systems that automatically modify pulsing of the light depending on ambient light intensity to enhance avoidance., Competing Interests: The authors declare there are no competing interests., (©2023 Lunn et al.)

Background: Germicidal ultraviolet (UV-C) light has been shown as an effective modality for disinfection in laboratory settings and in the operative room. Traditionally, short-wavelength UV-C devices, which have previously been shown to cause DNA damage, are utilized only for disinfection in pre- and post-operative settings and are not continuously active during operations. Continuous use of intraoperative UV light has potential to decrease pathogens and subsequent surgical site infections (SSIs), which arise in approximately 5-15% of operative cases. SSIs are a significant determinant of patient morbidity, readmission rates, and overall cost. Therefore, a method of UV light disinfection with a low risk of DNA damage is needed so that greater antimicrobial protection can be afforded to patients during the entirety of their surgical procedures. A new disinfection device that harnesses longer-wavelength UV-A light to disinfect the surgical field throughout the entirety of the procedure, including pre- and post-operation has been developed., Methods: This study aimed to determine if UV-A light administered intraoperatively was safe, as defined by the minimal presence of DNA damage and safe amounts of reflection upon medical personnel. Using in vitro models, we examined the differential impacts of UV-C and UV-A light on DNA damage and repair pathways. In a murine model, we looked at the production of DNA damage photoproduction in relation to UV-A versus UV-C exposure., Results: Our results show UV-A light does not induce a significant amount of DNA damage at the cellular or tissue level. Furthermore, a preclinical porcine study showed that surgical personnel were exposed to safe levels of UV-A irradiance from an overhead UV-A light used during an operation. The amount of UV-A transmitted through surgical personal protective equipment (PPE) also remained within safe levels., Conclusions: In conclusion, we found that UV-A may be safe for intraoperative use., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Guenter et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Noise and light levels during hospitalizations can disrupt sleep and circadian health, resulting in worsened health outcomes. This study describes patterns of noise and light for inpatient children undergoing stem cell transplants. Objective meters tracked noise and light levels every minute for 6 months. Median overnight sound was 55 dB (equivalent to conversational speech). There were 3.4 loud noises (>80 dB) per night on average. Children spent 62% of the 24-h cycle in nonoptimal lighting, with daytime light dimmer than recommended 98% of the time. Over the 6-month period, the lowest overnight noise level recorded exceeded World Health Organization recommendations for sleep, with frequent spikes into ranges known to cause wakings. During the day, children were rarely exposed to light sufficient to preserve healthy circadian rhythms. Hospitals should address systematic environmental and workflow disruptors to improve the sleep and circadian health of patients, particularly those already at elevated risk for health morbidities., (© 2023 Society of Hospital Medicine.)

Daily oscillations are present in many aspects of the immune system, including responsiveness to infections, allowing temporal alignment of defence mechanisms with the external environment. Our study addresses whether compromised circadian timing function by dim artificial light at night (ALAN) impacts the time dependency of the acute inflammatory response in a rat model of lipopolysaccharide (LPS)-induced inflammation. After 2 weeks of exposure to low-intensity ALAN (~2 lx) or a standard light/dark cycle, male rats were challenged with LPS during either the day or the night. Dim ALAN attenuated the anorectic response when rats were stimulated during their early light phase. Next, ALAN suppressed daily variability in inflammatory changes in blood leukocyte numbers and increased the daytime sensitivity of neutrophils to the priming effects of LPS on oxidative burst. An altered renal inflammatory response in ALAN-exposed rats was manifested by stimulated T-cell infiltration into the kidney upon night-time LPS injection and the modified rhythmic response of genes involved in inflammatory pathways. Moreover, ALAN disturbed steady-state oscillations of the renal molecular clock and eliminated the inflammatory responsiveness of Rev-erbα. Altogether, dim ALAN impaired time-of-day-dependent sensitivity of inflammatory processes, pointing out a causal mechanism between light pollution and negative health effects., (© 2023. Springer Nature Limited.)

Nocturnal light pollution can have profound effects on humans and other organisms. Recent research indicates that nighttime outdoor lighting is increasing rapidly. Evidence from controlled laboratory studies demonstrates that nocturnal light exposure can strain the visual system, disrupt circadian physiology, suppress melatonin secretion, and impair sleep. There is a growing body of work pointing to adverse effects of outdoor lighting on human health, including the risk of chronic diseases, but this knowledge is in a more nascent stage. In this Review, we synthesize recent research on the context-specific factors and physiology relevant to nocturnal light exposure in relation to human health and society, identify critical areas for future research, and highlight recent policy steps and recommendations for mitigating light pollution in the urban environment.

Anthropogenic light is ubiquitous in areas where humans are present and is showing a progressive increase worldwide. This has far-reaching consequences for most species and their ecosystems. The effects of anthropogenic light on natural ecosystems are highly variable and complex. Many species suffer from adverse effects and often respond in a highly specific manner. Ostensibly surveyable effects such as attraction and deterrence become complicated because these can depend on the type of behavior and specific locations. Here, we considered how solutions and new technologies could reduce the adverse effects of anthropogenic light. A simple solution to reducing and mitigating the ecological effects of anthropogenic light seems unattainable, because frugal lighting practices and turning off lights may be necessary to eliminate them.

Introduction: More than half of all fatalities on U.S. highways occur due to roadway departure (RwD) each year. Previous research has explored various risk factors that contribute to RwD crashes, however, a comprehensive investigation considering the effect of lighting conditions has been insufficiently addressed., Data: Using the Louisiana Department of Transportation and Development crash database, fatal and injury RwD crashes occurring on rural two-lane (R2L) highways between 2008-2017 were analyzed based on daylight and dark (with and without streetlight)., Method: This research employed a safe system approach to explore meaningful complex interactions among multidimensional crash risk factors. To accomplish this, an unsupervised data mining algorithm association rules mining (ARM) was utilized., Results and Conclusions: Based on the generated rules, the findings reveal several interesting crash patterns in the daylight, dark-with-streetlight, and dark-no-streetlight, emphasizing the importance of investigating RwD crash patterns depending on the lighting conditions. In daylight condition, fatal RwD crashes are associated with cloudy weather conditions, distracted drivers, standing water on the roadway, no seat belt use, and construction zones. In dark lighting condition (with and without streetlight), the majority of the RwD crashes are associated with alcohol/drug involvement, young drivers (15-24 years), driver condition (e.g., inattentive, distracted, illness/fatigued/asleep), and colliding with animal(s)., Practical Applications: The findings also reveal how certain driver behavior patterns are connected to RwD crashes, such as a strong association between alcohol/drug intoxication and no seat belt usage in the dark-no-streetlight condition. Based on the identified crash patterns and behavioral characteristics under different lighting conditions, the findings could aid researchers and safety specialists in developing the most effective RwD crash mitigation strategies., (Published by Elsevier Ltd.)

Excessive daytime sleepiness is a common presenting symptom that may present a diagnostic challenge for the sleep medicine clinician. We present a case of an adolescent female with excessive daytime sleepiness and "sleep attacks" who was evaluated using a 2-week sleep log, wrist actigraphy, baseline polysomnogram, and Multiple Sleep Latency Test. Multiple Sleep Latency Test results noted a short mean sleep latency without sleep onset rapid eye movement periods, concerning for possible central disorders of hypersomnolence. However, actigraphy data noted a habitual bedtime of midnight or later, resulting in less than recommended total sleep time for her age on weekdays with extended sleep periods on the weekends. The most unique actigraphy finding was exposure to ambient light throughout most overnight sleep periods. When actigraphy results were discussed with the patient, she revealed recent onset of severe anxiety with fear of sleeping in the dark. This case highlights the importance of thorough clinical evaluation, and careful interpretation of objective tests, when evaluating for causes of excessive daytime sleepiness., Citation: Dang L, Kanney ML, Hsu DP. The curious case of the Zzz's. J Clin Sleep Med . 2023;19(5):1009-1012., (© 2023 American Academy of Sleep Medicine.)

Objectives: In vitreoretinal surgery, there is always a conflict between bright illumination of the field of operation and retinal safety. This study aimed to investigate different light sources and light guides for their potential retinal risk due to bright illumination., Methods: Irradiances in the fovea of ex-vivo porcine eyes resulting from different light sources (halogen lamp, xenon lamp and LED) and light guides are investigated for varying distances between the illumination tip and the fovea. The results are examined with regard to their photochemical and thermal retinal hazard and the maximal exposure time. The examination is carried out with the maximum intensity setting of each light source and with normalization to its brightness., Main Results: With decreasing distance of the tip of the light source, the retinal hazard increases. The photochemical and thermal retinal hazard at maximum brightness are smallest for the halogen lamp, next for the xenon lamp and highest for the LED. Thus, the exposition time is the longest for the halogen lamp followed by the xenon lamp and the LED. Normalizing the results to the same brightness the maximum exposition time is nearly the same for xenon lamp and LED, but still higher in case of the halogen lamp., Conclusions: The choice of the most suitable lamp and illumination fiber depends on the intensity and spectral distribution of the illumination system. Concerning brightness, xenon and LED lamp are relatively harmless, but the surgeon should avoid the maximum device intensity., (Copyright © 2023 Elsevier Masson SAS. All rights reserved.)

Hormone-dependent cancers and overweight/obesity are not necessarily linked but might have similar underlying causes, such as circadian disruption, lack of physical activity, and unhealthy nutrition. Several empirical studies also attribute the rise in these types of morbidity to vitamin D deficiency, linked in turn to insufficient sunlight exposure. Other studies place an emphasis on melatonin (MLT) hormone suppression, associated with artificial light at night (ALAN) exposure. Yet no studies, carried out to date, have attempted to determine which of these environmental risk factors is associated stronger with the morbidity types in question. In this study, we aim to narrow this knowledge gap by analyzing data available for 100+ countries worldwide, while controlling ALAN and solar radiation exposure estimates by several potential confounders, such as GDP pc , GINI inequality index and unhealthy food consumption. As the study reveals, all the morbidity types under analysis are significantly and positively associated with ALAN exposure estimates ( p  < 0.05), while solar radiation appears to be significantly associated with prostate cancer rates only ( p  < 0.05), but not with breast cancer or overweight/obesity rates ( p  > 0.1). To the best of our knowledge, this study is the first that separates the effects of ALAN and daylight exposures on the abovementioned types of morbidity.

Background: Light pollution could represent one of the main drivers behind the current biodiversity erosion. While the effects of many light components on biodiversity have already been studied, the influence of flicker remains poorly understood. The determination of the threshold frequency at which a flickering light is perceived as continuous by a species, usually called the Critical Fusion Frequency (CFF), could thus help further identify the impacts of artificial lighting on animals., Objective: This review aimed at answering the following questions: what is the distribution of CFF between species? Are there differences in how flicker is perceived between taxonomic classes? Which species are more at risk of being impacted by artificial lighting flicker?, Methods: Citations were extracted from three literature databases and were then screened successively on their titles, abstracts and full-texts. Included studies were critically appraised to assess their validity. All relevant data were extracted and analysed to determine the distribution of CFF in the animal kingdom and the influence of experimental designs and species traits on CFF., Results: At first, 4881 citations were found. Screening and critical appraisal provided 200 CFF values for 156 species. Reported values of CFF varied from a maximum of between 300 Hz and 500 Hz for the beetle Melanophila acuminata D. to a mean of 0.57 (± 0.08) Hz for the snail Lissachatina fulica B. Insects and birds had higher CFF than all other studied taxa. Irrespective of taxon, nocturnal species had lower CFF than diurnal and crepuscular ones., Conclusions: We identified nine crepuscular and nocturnal species that could be impacted by the potential adverse effects of anthropogenic light flicker. We emphasize that there remains a huge gap in our knowledge of flicker perception by animals, which could potentially be hampering our understanding of its impacts on biodiversity, especially in key taxa like bats, nocturnal birds and insects., Competing Interests: The authors have read the journal’s policy and declare the following competing interests: Gaël Obein is the president of the AFE (French Lighting Association) and Virginie Nicolas is the president of the ACE (French Association of Lighting Designers and Lighting Engineers)., (Copyright: © 2022 Lafitte et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Purpose: Accumulating evidence suggests that light at night (LAN) disrupts circadian rhythms and may increase risk of liver cancer. However, there is no population-based study that examined LAN and liver cancer risk. Therefore, we aimed to investigate the association between outdoor LAN and liver cancer risk in a prospective cohort., Methods: Residential outdoor LAN level was measured from satellite imagery in the NIH-AARP Diet and Health Study, a prospective cohort of 451,945 men and women, 50-71 years old. Relative risks (RR) and 95% confidence intervals (CIs) were estimated using Cox proportional hazard models that adjusted for known risk factors for liver cancer and neighborhood characteristics., Results: During an average 12.2 years of follow-up, 897 liver cancers, 603 of which were hepatocellular carcinomas (HCC), were diagnosed. Residential outdoor LAN was not associated with risk of liver cancer (RR Q5 vs Q1  = 0.96, 95% CI: 0.77-1.20, p trend = 0.771) or HCC (RR Q5 vs Q1  = 0.82, 95% CI: 0.62-1.07, p trend = 0.425)., Conclusion: No association between outdoor LAN and risk of liver cancer or HCC may in part be due to limitations in LAN assessment. More studies on the relationship between light intensity, duration, timing, and wavelength and liver cancer are warranted., (© 2022. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Children with erythropoietic porphyria are generally under the care of paediatric dermatologists. When these children undergo major surgery, they are at risk of unusual complications due to their photosensitivity. Dermatologists may be consulted prior to surgery for advice. We describe a case of a child with erythropoietic porphyria undergoing open heart surgery, utilising an exchange transfusion alongside other strategies to minimise the risk of photosensitivity-induced haemolysis., (© 2021 Australasian College of Dermatologists.)

Light and noise pollution from human activity are increasing at a dramatic rate. These sensory stimuli can have a wide range of effects on animal behavior, reproductive success, and physiology. However, less is known about the functional and community-level consequences of these sensory pollutants, especially when they co-occur. Using camera traps in a manipulative field experiment, we studied the effects of anthropogenic light and noise, singularly and in tandem, on richness and community turnover at both the taxa and functional group level as well as foraging activity. We showed that both light and noise pollution did alter taxonomic richness and that these effects can differ depending on the scale of observation. Increases in light levels had a negative effect on richness at the camera-level scale, but light-treated sites had the highest pooled (i.e., cumulative) richness of all treatment types. In contrast, noise was found to have a negative effect on cumulative richness; however, when both stimuli were present, the addition of night-lighting mitigated the effects of noise. Artificial light and moonlight had the strongest influence on community turnover, and results remained consistent at both the taxa and functional group level. Additionally, increases in ambient noise and moonlight, but not artificial light, reduced foraging activity. Our study provides evidence that alterations to the sensory environment can alter the richness and composition of communities and that effects can be scale-dependent and also alter foraging behavior. Unexpectedly, the addition of artificial light may have mitigated the negative effects of noise on cumulative taxonomic richness. This highlights the importance of researching the consequences of co-exposure to these globally common pollutants., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Objective: Nurses working rotating shifts often suffer from insomnia or similar disorders because exposure to room lighting at night inhibits melatonin secretion, resulting in a disturbed circadian rhythm. This study investigated whether dark room lighting would be preferable to brighter rooms in terms of (1) fatigue and sleepiness while working, (2) quality of sleep and (3) non-interference with work performance among nurses., Methods: This study used a non-randomised open-label trial between night shifts using dark (110 lx) and bright (410 lx) room lighting on the desk surface. A total of 20 nurses were enrolled in the trial from November 2015 to February 2016 at a hospital in Japan. All participants worked first with dark room lighting and then with bright room lighting. The participants completed a self-administered questionnaire at enrolment, which was collected this at the end of the intervention., Results: Fatigue and sleepiness were significantly higher in dark room lighting than in bright room conditions (p<0.05). There were no significant differences in sleep quality between the dark and well-lit conditions. We detected no significant differences in the number of reported incidents or accidents comparing the two types of environments., Conclusion: Dark room lighting did not ameliorate fatigue and sleepiness during night shifts. Additionally, there was no evidence of improvement in sleep quality among nurses. These findings are important, however, in terms of managing hospital risk., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: Environmental light pollution due to artificial light may increase the rate and severity of retinal diseases, and plant-based nutritional interventions with antioxidant properties have the potential to reverse this phenomenon. We aimed to investigate the potential effects of allyl isothiocyanate (AITC) against white light-emitting diode (LED)-induced retinal degeneration (RD) in the rats., Methods: Twenty-eight male rats were allocated as: (i) Control, (ii) LED, (iii) LED + AITC (10 mg/kg BW), (iv) LED + AITC (20 mg/kg BW). Rats were administered with AITC for 28 days, followed by two days of intense environmental LED light (750 Lux ) exposure to the eyes. Animals were sacrificed immediately at the end of the study, then the blood and eyeballs were taken for the biochemical, western blotting, and histopathology examinations., Results: AITC lowered the serum and retina malondialdehyde (MDA) levels while significantly ( p <  0.05) improving the retinal antioxidant enzyme activities in a dose-dependent manner. AITC improved retinal and outer nuclear layer (ONL) thickness as compared to the LED group ( p <  0.05). AITC increased the levels of Bax, caspase-3, HO-1, GAP43, and VEGF, while decreasing IL-1β, IL-6, NF-κB, Bcl-2, GFAP, Grp78, activating ATF4 and ATF6 as compared to the LED group ( p <  0.05)., Conclusion: In conclusion, four weeks of AITC administration to the rats showed specific protective effects against two days of intense LED light-induced retinal damage; through antiinflammatory, antioxidant, anti-apoptotic, and modulating mitochondrial metabolic pathways.

Purpose: To evaluate the potential toxicity of operation microscopes with halogen and light emitting diode (LED) light source on the rabbit eyes., Materials and Methods: Thirty-two eyes of 16 male New Zealand pigmented rabbits were involved in the study. The rabbits were divided into two groups according to the type of light source applied. Only one eye of each rabbit was exposed to illumination light, unexposed fellow eyes served as the control group. Experimental groups included group 1 exposed to halogen light for 2 h and evaluated 1 day and 1 week after the illumination, group 2 exposed to LED light for two hours and evaluated 1 day and 1 week after the illumination. On the first and seventh days after exposing the light, we evaluated the rabbit corneas using in vivo confocal microscopy (IVCM). At the end of the seventh day, the Hematoxylin-eosin staining and TUNEL staining were performed to investigate the presence of apoptosis in the retina and retina pigment epithelium., Results: Early IVCM findings revealed corneal epithelial cell ovalization and indistinct intercellular borders in the halogen light group. We also observed more increase in the keratocyte density index (23.7% vs 14.1%, p  = 0.001, respectively) and the Bowman reflectivity index (12.4% vs 4.1%, p  = 0.001, respectively) at first day of the light exposure in halogen light group compared to LED light group. However, late IVCM indicated that these findings disappeared one week later. No apoptosis was observed in the corneal and retinal layers in early and late examination groups., Conclusion: The present experimental study demonstrated that both halogen and LED lights, which were commonly used for microscopic eye surgery, had no sustained adverse effect on the cornea and retina of the rabbits; however, halogen light had a temporary adverse effect on corneal epithelium and stroma, which resolved within 1 week.

A study of the influence of chronic alcohol intoxication, constant illumination and their combined effects on the morphofunctional state of the rat liver and the circadian rhythms (CR) of the studied parameters of the organism was carried out. It was found that both alcohol and constant illumination caused significant changes in the structure of the liver, as well as in the circadian rhythmicity of micromorphometric parameters of hepatocytes, ALT, and total and direct bilirubin rhythms; however, the combined effects of ethanol and constant illumination had the most significant effect on the studied parameters of the organism. These two factors caused disturbances in the circadian rhythms of the micromorphometric parameters of hepatocytes, disruption of the circadian rhythms of total protein, albumin, AST, ALT, and direct and total bilirubin, as well as disturbances in the expression and rhythmicity of the studied clock genes against a background of the development of an inflammatory process in the liver.

Competing Interests: Competing interests: We have read and understood BMJ policy on declaration of interests and have no interests to declare.

Artificial light at night (ALAN) is an increasing anthropogenic pollutant, closely associated with human population density, and now well recognized in both terrestrial and aquatic environments. However, we have a relatively poor understanding of the effects of ALAN in the marine realm. Here, we carried out a field experiment in the coral reef lagoon of Moorea, French Polynesia, to investigate the effects of long-term exposure (18-23 months) to chronic light pollution at night on the survival and growth of wild juvenile orange-fin anemonefish, Amphiprion chrysopterus . Long-term exposure to environmentally relevant underwater illuminance (mean: 4.3 lux), reduced survival (mean: 36%) and growth (mean: 44%) of juvenile anemonefish compared to that of juveniles exposed to natural moonlight underwater (mean: 0.03 lux). Our study carried out in an ecologically realistic situation in which the direct effects of artificial lighting on juvenile anemonefish are combined with the indirect consequences of artificial lighting on other species, such as their competitors, predators, and prey, revealed the negative impacts of ALAN on life-history traits. Not only are there immediate impacts of ALAN on mortality, but the decreased growth of surviving individuals may also have considerable fitness consequences later in life. Future studies examining the mechanisms behind these findings are vital to understand how organisms can cope and survive in nature under this globally increasing pollutant.

The performance of light microscopes is limited by the stochastic nature of light, which exists in discrete packets of energy known as photons. Randomness in the times that photons are detected introduces shot noise, which fundamentally constrains sensitivity, resolution and speed 1 . Although the long-established solution to this problem is to increase the intensity of the illumination light, this is not always possible when investigating living systems, because bright lasers can severely disturb biological processes 2-4 . Theory predicts that biological imaging may be improved without increasing light intensity by using quantum photon correlations 1,5 . Here we experimentally show that quantum correlations allow a signal-to-noise ratio beyond the photodamage limit of conventional microscopy. Our microscope is a coherent Raman microscope that offers subwavelength resolution and incorporates bright quantum correlated illumination. The correlations allow imaging of molecular bonds within a cell with a 35 per cent improved signal-to-noise ratio compared with conventional microscopy, corresponding to a 14 per cent improvement in concentration sensitivity. This enables the observation of biological structures that would not otherwise be resolved. Coherent Raman microscopes allow highly selective biomolecular fingerprinting in unlabelled specimens 6,7 , but photodamage is a major roadblock for many applications 8,9 . By showing that the photodamage limit can be overcome, our work will enable order-of-magnitude improvements in the signal-to-noise ratio and the imaging speed.

The COVID-19 pandemic has generated a great deal of interest in ultraviolet germicidal irradiation (UVGI) as an important means to disinfect air and surfaces. The traditional lamp employed for UVGI has been the low-pressure mercury-discharge lamp that emits primarily at 254 nm in the ultraviolet photobiological band UV-C (100-280 nm). The recent development of even shorter-wavelength UV-C lamps, such as the Krypton-Chloride, 222-nm lamp, has led to greater concerns about the UV-C generation of ozone. It is well known that wavelengths below 240 nm more readily generate ozone. However, there is a great misunderstanding with regard to the actual generation and dissipation of ozone molecules by UV-C lamps. A review of this subject is much warranted. An overview of the ozone generation of various UV-C light sources is presented to give users a better understanding of risk and how to assure control of ozone when employing UV-C lamps., (© 2021 American Society for Photobiology.)

Background: Light at night (LAN) inhibits nighttime secretion of melatonin and may cause circadian disruption, which may be a risk factor for cancer. Recent studies have linked high LAN exposure with elevated breast cancer risk. Given that breast cancer may share a common hormone-dependent etiology with thyroid cancer and that circadian rhythms play a role in regulating thyroid function, the authors hypothesized that exposure to LAN is positively associated with thyroid cancer incidence., Methods: This study examined the association between LAN and thyroid cancer incidence in the National Institutes of Health-American Association of Retired Persons Diet and Health Study. LAN exposure was estimated from satellite data and was linked to residential addresses at the baseline. Incident thyroid cancer cases were ascertained via linkage to state cancer registries. Cox regression was used to determine the relationship between LAN and thyroid cancer risk, with adjustments made for sociodemographic, lifestyle, and other environmental factors., Results: Among 464,371 participants, a positive association was found between LAN and thyroid cancer risk. Specifically, in comparison with the lowest quintile of LAN, the highest quintile was associated with a 55% increase in risk (hazard ratio [HR], 1.55; 95% confidence interval [CI], 1.18-2.02). The association was primarily driven by papillary thyroid cancer and was stronger in women (HR, 1.81; 95% CI, 1.26-2.60) than men (HR, 1.29; 95% CI, 0.86-1.94). In women, the association was stronger for localized cancer, whereas in men, the association was stronger for a more advanced stage. Results were consistent across different tumor sizes., Conclusions: LAN was positively associated with thyroid cancer risk. Future studies are needed to confirm this association and identify underlying biological mechanisms., (© 2021 American Cancer Society.)

Despite experimental and mechanistic data suggesting circadian disruption's role in carcinogenesis, mixed findings from epidemiological investigations of artificial light at night and cancer risk in the general population are difficult to interpret due to exposure assessment limitations. It will be important for future studies to assess and validate individual-level exposures, ideally over the lifetime.

Holometabolous insects exhibit complex life cycles in which both morphology and ecological niche change dramatically during development. In the larval stage, many insects have soft, slow-moving bodies and poor vision, limiting their ability to respond to environmental threats. Artificial light at night (ALAN) is an environmental perturbation known to severely impact the fitness of adult insects by disrupting both temporal and spatial orientation. The impact of ALAN on earlier life stages, however, is largely unknown. We conducted a series of laboratory experiments to investigate how two distinct forms of ALAN affect the development and movement of immature Photuris sp. and Photinus obscurellus fireflies. Although long-term exposure to dim light at night (dLAN), akin to urban skyglow, did not impact overall survivorship or duration of egg, larval, and pupal stages in either species, it did accelerate weight gain in early-instar Photuris larvae. Late-instar Photuris exposed to point sources of ALAN at the start of their nightly foraging period were also significantly more likely to burrow beneath the soil surface, rather than disperse across it. ALAN may therefore impede dispersal of firefly larvae away from illuminated areas, which could have downstream consequences for the reproductive fitness of adults., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Circadian disruption may play a role in carcinogenesis. Recent research suggests that light at night (LAN), a circadian disruptor, may be a risk factor for cancer. Moreover, LAN has been linked to obesity and diabetes, two risk factors for pancreatic ductal adenocarcinoma (PDAC). Here we examine the relationship between LAN and PDAC in an epidemiologic study of 464,371 participants from the NIH-AARP Diet and Health Study. LAN was estimated from satellite imagery at baseline (1996), and incident primary PDAC cases were ascertained from state cancer registries. Cox proportional hazards models were used to estimate HRs and two-sided 95% confidence intervals (CI) for the association between quintiles of LAN and PDAC in the overall population stratified by sex. Over up to 16.2 years of follow-up, a total of 2,502 incident PDAC were identified in the cohort. Higher estimated LAN exposure was associated with an elevated PDAC risk. Compared with those living in areas in the lowest LAN quintile, those in areas in the highest quintile had a 27% increase PDAC risk [HR (95% CI), 1.24 (1.03-1.49)], with similar risk for men [1.21 (0.96-1.53)] and women [1.28 (0.94-1.75)]. In addition, stronger associations were observed in normal and overweight groups compared with the obese group ( P interaction = 0.03). Our results support the hypothesis that LAN and circadian disruption may be risk factors for PDAC. SIGNIFICANCE: Our study suggests that higher LAN is a risk factor for pancreatic cancer, contributing to the growing literature that demonstrates the potentially adverse health effects of light pollution., (©2021 American Association for Cancer Research.)

Artificial light at night (ALAN) can have negative impacts on the health of humans and ecosystems. 1-4 Marine organisms, including coral reefs in particular, rely on the natural light cycles of sunlight and moonlight to regulate various physiological, biological, and behavioral processes. 5-8 Here, we demonstrate that light pollution caused delayed gametogenesis and unsynchronized gamete release in two coral species, Acropora millepora and Acropora digitifera, from the Indo-Pacific Ocean. Given the urbanization along major coasts, light pollution could thus further threaten coral communities' populations, which are already under severe degradation. A worldwide-modeled light pollution impact assessment is provided, which can help incorporate an important variable in coral reef conservation planning., Competing Interests: Declaration of Interests The authors declare no competing interests., (Copyright © 2020 Elsevier Inc. All rights reserved.)

We performed optical radiation safety evaluations of LED flashlights to determine if they pose potential ocular hazards. Six commercially available flashlight samples were randomly selected from various vendors online. They were evaluated in accordance with specifications provided in the American National Standards Institute/Illuminating Engineering Society of North America (ANSI/IESNA) Standards RP 27.1 and RP 27.3. Four of the flashlights were found to have relatively high blue-light-weighted radiance values with short times (40 to 50 s) to reach the exposure limit specified in RP 27.1. These flashlights are in Risk Group 2 and present a moderate risk for retinal damage. Two of the flashlights are in Risk Group 1 and present a low risk for retinal damage. None of the flashlights present an ultraviolet (UV) radiation hazard or a retinal thermal hazard. Cautionary labeling on the packaging as required by RP 27.3 and on the flashlight handle is recommended for flashlights and on other handheld light sources that are in Risk Group 2 or Risk Group 3.

Artificial light exposure is associated with dyslipidemia in humans, which is a major risk factor for the development of atherosclerotic cardiovascular disease. However, it remains unclear whether artificial light at night can exacerbate atherosclerosis. In this study, we exposed female APOE*3-Leiden.CETP mice, a well-established model for human-like lipid metabolism and atherosclerosis, to either a regular light-dark cycle or to constant bright light for 14 weeks. Mice exposed to constant light demonstrated a minor reduction in food intake, without any effect on body weight, body composition, or the weight of metabolic organs. Constant light increased the plasma levels of proatherogenic non-high-density lipoprotein (HDL) cholesterol but did not increase the size or severity of atherosclerotic lesions in the aortic root. Mice exposed to constant light did show lower immune cell counts, which could explain the absence of an effect of atherosclerosis despite increased non-HDL cholesterol levels. Behavioral analysis demonstrated variability in the response of mice to the light intervention. Constant light completely blunted behavioral rhythms in some mice, while others extended their behavioral period. However, rhythm strength was not an important determinant of atherosclerosis. Altogether, these results demonstrate that constant bright light does not affect atherosclerosis in APOE*3-Leiden.CETP mice. Whether artificial light exposure contributes to cardiovascular disease risk in humans remains to be investigated.

Nighttime light pollution is linked to metabolic and cognitive dysfunction. Many patients with autism spectrum disorders (ASD) show disturbances in their sleep/wake cycle, and may be particularly vulnerable to the impact of circadian disruptors. In this study, we examined the impact of exposure to dim light at night (DLaN, 5 lx) in a model of ASD: the contactin associated protein-like 2 knock out (Cntnap2 KO) mice. DLaN was sufficient to disrupt locomotor activity rhythms, exacerbate the excessive grooming and diminish the social preference in Cntnap2 mutant mice. On a molecular level, DLaN altered the phase and amplitude of PER2:LUC rhythms in a tissue-specific manner in vitro. Daily treatment with melatonin reduced the excessive grooming of the mutant mice to wild-type levels and improved activity rhythms. Our findings suggest that common circadian disruptors such as light at night should be considered in the management of ASD., Competing Interests: Declaration of competing interest Dr. Colwell received research funding from Takeda Pharmaceuticals from 2015 to 2017. The authors of this work have no financial interests related to this manuscript., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Expansion of anthropogenic noise and night lighting across our planet 1,2 is of increasing conservation concern 3-6 . Despite growing knowledge of physiological and behavioural responses to these stimuli from single-species and local-scale studies, whether these pollutants affect fitness is less clear, as is how and why species vary in their sensitivity to these anthropic stressors. Here we leverage a large citizen science dataset paired with high-resolution noise and light data from across the contiguous United States to assess how these stimuli affect reproductive success in 142 bird species. We find responses to both sensory pollutants linked to the functional traits and habitat affiliations of species. For example, overall nest success was negatively correlated with noise among birds in closed environments. Species-specific changes in reproductive timing and hatching success in response to noise exposure were explained by vocalization frequency, nesting location and diet. Additionally, increased light-gathering ability of species' eyes was associated with stronger advancements in reproductive timing in response to light exposure, potentially creating phenological mismatches 7 . Unexpectedly, better light-gathering ability was linked to reduced clutch failure and increased overall nest success in response to light exposure, raising important questions about how responses to sensory pollutants counteract or exacerbate responses to other aspects of global change, such as climate warming. These findings demonstrate that anthropogenic noise and light can substantially affect breeding bird phenology and fitness, and underscore the need to consider sensory pollutants alongside traditional dimensions of the environment that typically inform biodiversity conservation.

The outcomes of species interactions-such as those between predators and prey-increasingly depend on environmental conditions that are modified by human activities. Light is among the most fundamental environmental parameters, and humans have dramatically altered natural light regimes across much of the globe through the addition of artificial light at night (ALAN). The consequences for species interactions, communities and ecosystems are just beginning to be understood. Here we present findings from a replicated field experiment that simulated over-the-water lighting in the littoral zone of a small lake. We evaluated responses by emergent aquatic insects and terrestrial invertebrate communities, and riparian predators (tetragnathid spiders). On average ALAN plots had 51% more spiders than control plots that were not illuminated. Mean individual spider body mass was greater in ALAN plots relative to controls, an effect that was strongly sex-dependent; mean male body mass was 34% greater in ALAN plots while female body mass was 176% greater. The average number of prey items captured in spider webs was 139% greater on ALAN mesocosms, an effect attributed to emergent aquatic insects. Non-metric multidimensional scaling and a multiple response permutation procedure revealed significantly different invertebrate communities captured in pan traps positioned in ALAN plots and controls. Control plots had taxonomic-diversity values (as H') that were 58% greater than ALAN plots, and communities that were 83% more-even. We attribute these differences to the aquatic family Caenidae which was the dominant family across both light treatments, but was 818% more abundant in ALAN plots. Our findings show that when ALAN is located in close proximity to freshwater it can concentrate fluxes of emergent aquatic insects, and that terrestrial predators in the littoral zone can compound this effect and intercept resource flows, preventing them from entering the terrestrial realm., Competing Interests: The authors have declared that no competing interests exist.

Artificial lighting at night (ALAN) is increasingly recognised as having negative effects on many organisms, though the exact mechanisms remain unclear. Glow worms are likely susceptible to ALAN because females use bioluminescence to signal to attract males. We quantified the impact of ALAN by comparing the efficacy of traps that mimicked females to attract males in the presence or absence of a white artificial light source (ALS). Illuminated traps attracted fewer males than did traps in the dark. Illuminated traps closer to the ALS attracted fewer males than those further away, whereas traps in the dark attracted similar numbers of males up to 40 m from the ALS. Thus, ALAN impedes females' ability to attract males, the effect increasing with light intensity. Consequently, ALAN potentially affects glow worms' fecundity and long-term population survival. More broadly, this study emphasises the potentially severe deleterious effects of ALAN upon nocturnal insect populations., Competing Interests: Competing interestsThe authors declare no competing or financial interests., (© 2020. Published by The Company of Biologists Ltd.)

Dim light at night (dLAN) is associated with metabolic risk but the specific effects on lipid metabolism have only been evaluated to a limited extent. Therefore, to explore whether dLAN can compromise lipid metabolic homeostasis in healthy individuals, we exposed Wistar rats to dLAN (~2 lx) for 2 and 5 weeks and analyzed the main lipogenic pathways in the liver and epididymal fat pad, including the control mechanisms at the hormonal and molecular level. We found that dLAN promoted hepatic triacylglycerol accumulation, upregulated hepatic genes involved in de novo synthesis of fatty acids, and elevated glucose and fatty acid uptake. These observations were paralleled with suppressed fatty acid synthesis in the adipose tissue and altered plasma adipokine levels, indicating disturbed adipocyte metabolic function with a potential negative impact on liver metabolism. Moreover, dLAN-exposed rats displayed an elevated expression of two peroxisome proliferator-activated receptor family members ( Pparα and Pparγ ) in the liver and adipose tissue, suggesting the deregulation of important metabolic transcription factors. Together, our results demonstrate that an impaired balance of lipid biosynthetic pathways caused by dLAN can increase lipid storage in the liver, thereby accounting for a potential linking mechanism between dLAN and metabolic diseases.

Light conditions in retail stores may contribute to potato greening. In this study, we aimed to develop a potato tuber greening risk rating model for retail stores based on light quality and intensity parameters. This was achieved by firstly exposing three potato varieties (Nicola, Maranca and Kennebec) to seven specific light wavelengths (370, 420, 450, 530, 630, 660 and 735 nm) to determine the tuber greening propensity. Detailed light quality and intensity measurements from 25 retail stores were then combined with the greening propensity data to develop a tuber greening risk rating model. Our study showed that maximum greening occurred under blue light (450 nm), while 53%, 65% and 75% less occurred under green (530 nm), red (660 nm) and orange (630 nm) light, respectively. Greening risk, which varied between stores, was found to be related to light intensity level, and partially explained potato stock loss in stores. Our results from this study suggested that other in-store management practices, including lighting duration, average potato turnover, and light protection during non-retail periods, likely influence tuber greening risk., Competing Interests: The authors have declared that no competing interests exist.

Rationale: Light pollution leads to high risk of obesity but the underlying mechanism is not known except for the influence of altered circadian rhythm. Peroxisome proliferator-activated receptor α (PPARα) regulates lipid metabolism, but its role in circadian-related obesity is not clear. Methods: Wild-type (WT) and Ppara- null (KO) mice on a high-fat diet (HFD) were treated with neon light at night for 6 weeks. Body weights were recorded and diet consumption measured. The hypothalamus, liver, adipose and serum were collected for mechanism experimentation. Results: WT mice on a HFD and exposed to night neon light gained about 19% body weight more than the WT control mice without light exposure and KO control mice on a HFD and exposed to night neon light. The increase in adipose tissue weight and adipocyte size led to the differences in body weights. Biochemical analysis suggested increased hepatic lipid accumulated and increased transport of lipid from the liver to peripheral tissues in the WT mice that gained weight under neon light exposure. Unlike KO mice, the expression of genes involved in lipid metabolism and the circadian factor circadian locomotor output cycles kaput (CLOCK) in both liver and adipose tissues were elevated in WT mice under neon light exposure. Conclusions: PPARα mediated weight gain of HFD-treated mice exposed to night neon light. More lipids were synthesized in the liver and transported to peripheral tissue leading to adaptive metabolism and lipid deposition in the adipose tissue. These data revealed an important mechanism of obesity induced by artificial light pollution where PPARα was implicated., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)