Health Effects of Disrupted Circadian Rhythms by Artificial Light at Night

Life on Earth has adapted to the changing patterns of light and darkness caused by the Earth's rotation. Known as circadian rhythms, these 24 h biological rhythms are regulated through light exposure and coordinate a range of behaviors such as sleep-wake cycles, eating, activity levels, and more. However, artificial light at night can disrupt these rhythms, altering how the human internal clock regulates sleep, metabolism, and even mood. This paper discusses some common forms of circadian disruption, such as nighttime light pollution and shift work, and examines the associated health outcomes. Some policy insights for reducing circadian disruption include regulating shift work, updating public lighting, and incentivizing circadian-based technologies. Regulating artificial lighting can improve human health and wellbeing, protect wildlife, and will allow future generations to continue enjoying starry nights.