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Restricted Campus Only

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Light pollution is an environmental hazard that has multiple negative cultural, economic, and environmental impacts. Additionally, light pollution disrupts human circadian rhythms, which are in turn associated with increased rates of sleep disorders, obesity, and cancer. However, the environmental justice movement often overlooks the issue of light pollution, even though light pollution is higher in urban low-income areas. There is a lack of studies examining how light pollution varies between communities on a regional, state, or municipal scale. To assess the distribution of light pollution and its effects across San Antonio, we measured light pollution on 90 residential streets belonging to three distinct income brackets. We also recorded the streetlight bulb type. The mid-income neighborhoods had the greatest median and maximum light pollution levels, while high-income neighborhoods had the lowest median illuminance. These results indicate that mid-income neighborhoods are subject to the greatest amount of light pollution by area and intensity. Additionally, we found that light pollution has weak positive trends with obesity, sleep loss, and crime, but it is not predictive of these phenomena. Based on our findings, we conclude that light pollution differentially affects San Antonians based upon income class, and the city should consider light pollution to be an environmental injustice. Using our findings and various case studies as a guide, we suggest updates to San Antonio’s existing urban lighting policies, such as adding a yearly cap on the growth rate of new light fixtures, ensuring full shielding for light fixtures, and adopting a part-night lighting system.