This limited evidence associating ALAN with cancer may be related to the lack of a quantitative assessment of ALAN and melatonin levels in human studies. Further systemic reviews found insufficient evidence to support an association between night shift work and breast cancer risk and recent review study reported no evidence for a dose relationship between night-shift work and breast cancer risk. In 2007, the International Agency for Research on Cancer (IARC) classified вЂњshift work that involves circadian disruptionвЂќ as a probable human carcinogen, based on limited evidence of carcinogenicity for breast cancer in human studies and sufficient evidence in experimental animals. Д®vening and night shift workers have a greater risk for exposure to both ALAN and irregular light-dark patterns, and have been shown to be at increased risk for diseases, especially cancer. Furthermore, it has been suggested that ALAN is also associated with a higher risk of cardiovascular disease and psychiatric disorders such as depression. An increase in cancer has been proposed to be the result of the simultaneous, complex effects of three major mechanisms related to circadian disruption by ALAN: inhibition of melatonin secretion, sleep deprivation and chronodisruption. Most studies have reported the effects of ALAN on disruption of metabolic processes, resulting in obesity or diabetes and cancer incidence.

Exposure to ALAN can also induce broad endocrine effects through direct altering endocrine signal by circadian dyregulation or disrupted melatonin production. Exposure to dim light during sleep lead to problems with sleep and cognition. Abnormal lighting conditions induce many negative consequences on these rhythms, including both an acute impact on alertness and cognition, and an indirect effect through dysregulation of the circadian system. Throughout the body, tissue functions are influenced by light, and circadian rhythms are aligned by photoentrainment. Keywords: Circadian rhythm, Sleep disruption, Cognition, Melatonin, Shift work INTRODUCTION INTRODUCTION Shift workers may be regarded as an extreme ALAN-exposure group, but the growing use of electronic devices and lifestyle changes in the general population make difficult to differentiate ALAN risks to health. The present review considers articles investigating the risk of ALAN for shift workers, the general population, and users of electronic devices, and addresses susceptibility factors, including age, sex, and chronotype.

The development of surrogate markers and critical parameters is crucial for health study by ALAN exposure, and such markers should include risk factors related to ALAN exposure.

Increasing use of electronic devices makes it difficult to assess ALAN exposure in the general population.

Studies have revealed a significant increase in breast cancer in high ALAN-polluted areas, although the correlation with outdoor or indoor lighting conditions is controversial. Although shift workers may be exposed to extreme ALAN, its impact on their health is obscured by factors such as daylight exposure, meal and sleep scheduling, and physical and social behavior. Artificial light at night (ALAN) negatively influences the circadian system, inducing acute effects on sleep and cognition, as well as chronic endocrine-disrupting effects resulting in obesity, cardiovascular disease, diabetes, and cancer. Light is an important entraining agent for endogenous circadian rhythms.

Artificial academy 2 lag 2019