LIGHT POLLUTION: a systematic review about the impacts of artificial light on human health

ABSTRACT As industry and economy progress, human exposure to artificial light increases. Thus, the aim was to analyze the scientific evidence about the light pollution effect on human health, focusing on the main human pathologies and the types of polluting lights. A systematic review was carried out following the PRISMA guidelines, searching for original articles in the PubMed/Medline, Scielo and Web of Science, using the descriptors (light[title]) AND (health), and the key words “light pollution” and “(light at night) AND (health)”. The result shows that human exposure occurs through lights from electronic devices and artificial (ambient, and external) light at night. Human alterations most described were sleep disturbances, circadian rhythm, melatonin, and cortisol alterations. In addition, were described mood alterations and depression, alterations in spermatogenesis, ocular structures, thermoregulation, and other cardiovascular diseases. The pathways described were: i) changes in melatonin levels, and circadian rhythm, ii) directly stimulation of photoreceptors sensitive to light in ganglion cells, iii) activation of oxidative stress, and iv) alteration in specific metabolites by activating stress genes. It is concluded that the increase in exposure to artificial light triggers mainly sleep and mood disorders, with light from electronic devices and artificial night the mains source of pollution.