Last updated on Jun 22nd, 2021 at 11:36 am

Exposure to electronic blue light at night – the kind emitted from the screens of digital devices – has been linked to breast and prostate cancer…

An evening digital switch-off time for computers, TVs and mobile phones could be a good idea.

According to a new study, nighttime exposure to the electronic blue light these devices emit increases the risks of breast and prostate cancer.

What is blue light?

Blue light is a range of the visible light spectrum emitted by most white LEDs and many tablet and phone screens.

“We know that depending on its intensity and wavelength, artificial light, particularly in the blue spectrum, can decrease melatonin production and secretion,” says Martin Aubé, physics professor at CÉGEP in Sherbrooke, Canada and study co-author.

Subscribe to our Free Daily All4Women Newsletter to enter

Cancer loves the night shift

“WHO’s International Agency for Research on Cancer (IARC) has classified night shift work as probably carcinogenic to humans. There is evidence pointing to an association between exposure to artificial light at night, disruption of the circadian rhythm, and breast and prostate cancers. With this study we sought to determine whether night exposure to light in cities can affect the development of these two types of cancer,” explains Manolis Kogevinas, ISGlobal researcher and coordinator of the study.

Nighttime exposure to the electronic blue light these devices emit increases the risks of breast and prostate cancer

Related: How to protect children from screen time eye damage

Over 4 000 people studied

The study includes medical and epidemiological data of more than 4 000 people between 20 and 85 years of age in 11 Spanish regions.

Indoor exposure to artificial light was determined through personal questionnaires, while outdoor levels of artificial light were evaluated for Madrid and Barcelona, based on nocturnal images taken by astronauts aboard the International Space Station.

Results obtained for both cities show that participants exposed to higher levels of blue light had a 1,5 and two-fold higher risk of developing breast and prostate cancer, respectively, as compared to the less-exposed population.

Source: Barcelona Institute for Global Health (ISGlobal) via

While All4Women endeavours to ensure health articles are based on scientific research, health articles should not be considered as a replacement for professional medical advice. Should you have concerns related to this content, it is advised that you discuss them with your personal healthcare provider.