Posted by 
The blue light from smartphones, tablets and LED street lights may cause cancer. Exposure to high levels of blue light at night increases the risk of breast and prostate cancer, an international study involving the University of Exeter found. The light which glows from electronic devices disrupt human body clocks, affect hormones which can lead to cancer, according to the findings on blue light, which also shines into homes from the LED street lights.
Researchers led by Barcelona Institute for Global Health found people exposed to outdoor and indoor blue light increased their cancer risk, based on a study of more than 4,000 people in 11 regions. Humans have evolved to need light during the day and darkness at night. As towns and cities replace older lighting, people are exposed to higher levels of ‘blue’ lights, which can disrupt biological clocks.
Blue light has long been suspected to be the reason that night shift workers, exposed to artificial light for longer, have a greater risk of cancer. Blue light has one of the shortest wavelengths, cuts the body’s production of melatonin, which plays a key role in regulating the body clock. This may disrupt other hormones, prostate and breast cancer are hormone-related.
Researchers measured outdoor blue light in Barcelona and Madrid using images from the International Space Station which measured three visible bands of light – blue, red and green. People who were exposed to blue light from street lamps at night had a higher risk of breast and prostate cancer.
Indoor light was recorded by asking people if they slept in total darkness, an almost dark room, dim light or were ‘quite illuminated’.
While there was no effect on breast cancer, men who reported sleeping in quite well-lit bedrooms had a higher risk of prostate cancer than those in the dark.
The World Health Organisation’s International Agency for Research on Cancer (IARC) has classified night shift work as carcinogenic to humans. There is a link between exposure to artificial light at night, disruption of the circadian rhythm, and breast and prostate cancers.
haleplushearty.org