Natural light exposure, sleep and depression among day workers and shiftworkers at arctic and equatorial latitudes.

• Published in: PLOS ONE
• Main Authors: Elaine Cristina Marqueze, Suleima Vasconcelos, Johanna Garefelt, Debra J Skene, Claudia Roberta Moreno, Arne Lowden
• Format: Article in Journal/Newspaper
• Language: English
• Published: Public Library of Science (PLoS) 2015
• Subjects: Medicine; R; Science; Q; Arctic
• Online Access: https://doi.org/10.1371/journal.pone.0122078; https://doaj.org/article/4b8cbf64fe86400aa80e5a17f63fc379

This study aimed to investigate the relationship between individual natural light exposure, sleep need, and depression at two latitudes, one extreme with a few hours of light per day during winter, and the other with equal hours of light and darkness throughout the year.This cross-sectional study included a sample of Brazilian workers (Equatorial, n = 488 workers) and a Swedish sample (Arctic, n = 1,273).The reported mean total natural light exposure per 4-week cycle differed significantly between the Equatorial and Arctic regions. However, shiftworkers from both sites reported similar hours of natural light exposure. Short light exposure was a predictor for insufficient sleep.Reduced exposure to natural light appears to increase the perception of obtaining insufficient sleep. Arctic workers were more prone to develop depression than Equatorial workers.