The American Medical Association adopted recommendations based on a report that certain types of nighttime lighting can adversely affect health and may be linked to breast cancer and other medical conditions.
Dr. Steven Lockley, a professor of medicine at Harvard University and one of the report’s four authors, said the AMA’s policies will help educate the public about artificial light, particularly regarding the risks of working night shifts. Studies consistently have shown that shift workers are at a higher risk for breast cancer, heart disease and other health problems.
Dr Steven Lockley has been studying the effects of nighttime lighting for 25 years and was the first researcher to raise the possibility that there might be a connection to breast cancer.
Like a lot of new scientific concepts, the theory seemed on the fringe at first. But it has slowly gained traction, and more researchers since have focused on other possible adverse health effects of artificial lighting, such as obesity and mood and sleep disorders.
Exposure to artificial light for prolonged periods will disrupt the body’s biological clock that regulates sleep and wakefulness, known as circadian rhythms. Electric light — around for only the past 150 years — has impaired these natural rhythms, which have evolved over millions of years. As a result, hormone and melatonin levels are disrupted and that could lead to the onset of breast cancer.
“The natural 24-hour cycle of light and dark helps maintain alignment of circadian biological rhythms along with basic processes that help our bodies to function normally”,……..” Excessive exposure to nighttime lighting disrupts these essential processes and can create potentially harmful health effects and hazardous situations.”
The report calls artificial light “a man-made self-experiment” that throws sleep out of whack. It also asserts that excessive light at night — including light from TVs and computers — can cause sleep disorders, especially in children and adolescents.