Goldblatt, R., Stuhlmacher, M. F., Tellman, B., Clinton, N., Hanson, G., Georgescu, M., et al. (2018). Using Landsat and nighttime lights for supervised pixel-based image classification of urban land cover. Remote Sensing of Environment, 205, 253–275.
Abstract: Reliable representations of global urban extent remain limited, hindering scientific progress across a range of disciplines that study functionality of sustainable cities. We present an efficient and low-cost machine-learning approach for pixel-based image classification of built-up areas at a large geographic scale using Landsat data. Our methodology combines nighttime-lights data and Landsat 8 and overcomes the lack of extensive ground-reference data. We demonstrate the effectiveness of our methodology, which is implemented in Google Earth Engine, through the development of accurate 30 m resolution maps that characterize built-up land cover in three geographically diverse countries: India, Mexico, and the US. Our approach highlights the usefulness of data fusion techniques for studying the built environment and is a first step towards the creation of an accurate global-scale map of urban land cover over time.
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Stewart, A. J. A., Perl, C. D., & Niven, J. E. (2020). Artificial lighting impairs mate attraction in a nocturnal capital breeder. J Exp Biol, 223(Pt 19).
Abstract: 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.
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Walker, W. H. 2nd, Bumgarner, J. R., Walton, J. C., Liu, J. A., Melendez-Fernandez, O. H., Nelson, R. J., et al. (2020). Light Pollution and Cancer. Int J Mol Sci, 21(24).
Abstract: For many individuals in industrialized nations, the widespread adoption of electric lighting has dramatically affected the circadian organization of physiology and behavior. Although initially assumed to be innocuous, exposure to artificial light at night (ALAN) is associated with several disorders, including increased incidence of cancer, metabolic disorders, and mood disorders. Within this review, we present a brief overview of the molecular circadian clock system and the importance of maintaining fidelity to bright days and dark nights. We describe the interrelation between core clock genes and the cell cycle, as well as the contribution of clock genes to oncogenesis. Next, we review the clinical implications of disrupted circadian rhythms on cancer, followed by a section on the foundational science literature on the effects of light at night and cancer. Finally, we provide some strategies for mitigation of disrupted circadian rhythms to improve health.
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Cote-Lussier, C., Knudby, A., & Barnett, T. A. (2020). A novel low-cost method for assessing intra-urban variation in night time light and applications to public health. Soc Sci Med, 248, 112820.
Abstract: Night time lighting (NTL) pollution is a public health concern given its known impact on a range of health outcomes. The daily cycle of the hue of natural ambient light shifting from relatively blue-white light at noon to relatively yellow-red light at sunset is important for human functioning. Disruptions of the circadian clock can result in melatonin suppression, sleep and mood disorders, and increased risks of cancer in adults. Current measures of intra-urban variation in NTL are based on costly in-person or coarse satellite image-based assessments. The central objective of the current study is to validate a novel low-cost measure of intra-urban NTL variation. Estimates of red, green and blue NTL intensity were derived from a cloud-free night time image of the city of Montreal, Canada, taken from the International Space Station (ISS). The new measures are shown to converge with in-person assessed NTL and to predict known child health-related outcomes. Specifically, the results suggest that ISS-assessed blue NTL is associated with feelings of safety and self-reported health. In conclusion, ISS-based measures of NTL, particularly of blue NTL, are valid indicators of intra-urban variation in NTL for applications in public health. Limitations of, and future directions for, the method are discussed.
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Zhang, S., Wang, Y., Zhu, Y., Li, X., Song, Y., & Yuan, J. (2020). Rotating Night Shift Work, Exposure to Light at Night, and Glomerular Filtration Rate: Baseline Results from a Chinese Occupational Cohort. Int J Environ Res Public Health, 17(23).
Abstract: The misalignment between the circadian clock and behavioral cycles has been implicated in pathogenesis of many diseases. The main purpose of this study is to examine the association between rotating night shift work, exposure to light at night, and glomerular filtration rate among steelworkers in north China. A total of 6869 steelworkers, aged 22 to 60 years, were included in this study. Multivariable logistic regression was used to examine the association between night shift work, the brightness of bedroom ambient light at night (LAN), and estimated glomerular filtration rate (eGFR), with adjustment for potential confounders. Mediation analysis was performed to examine the mediation effect of potential mediators on the association of duration of night shifts and eGFR. Long duration of night shift work (>/=29 years) had elevated odds of decreased eGFR (</=89 mL/min/1.73 m(2)) (odds ratio (OR), 1.37, 95% confidence interval (CI) 1.09-1.73) compared with day work after adjustment for potential confounders. The association between duration of night shifts and eGFR (continuous) was partially modified by diastolic blood pressure (average causal mediation effect (ACME), -0.077, 95% CI -0.134 to -0.030, p < 0.001). No significant associations were observed among the different brightness of bedroom ambient light levels: middle level (OR, 0.90, 95% CI 0.77-1.05), lightest level (OR, 0.94, 95% CI 0.75-1.18), and decreased eGFR compared with the darkest level. Long-term night-shift work, rather than the brightness of bedroom ambient LAN, is associated with early stage of renal dysfunction in steelworkers, and blood pressure may mediate the relationship between night shift work and decreased eGFR.
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