Sammanfattning
Shift and night work is among the most frequent occupational exposures. Such work schedules involve exposure to light-at-night, which may reduce normal nocturnal melatonin production, create circadian rhythm disruption, sleep deprivation and unhealthy live-style. There is strong experimental evidence that light-at-night and circadian disruption may increase the risk of cancer and coronary heart diseases. There is emerging, but limited epidemiologic evidence that night shift work may increase breast cancer and certain cardiovascular diseases.