New Study Claims Blue Light from Smartphones and Outdoor LED Lighting May Increase Risk of Cancer

A new study published in Environmental Health Standards says exposure to the type of blue light emitted from tablets, smartphones and outdoor LED lighting may increase your risk of prostate or breast cancer. The study, which used subjects from both Barcelona and Madrid, compared the subject’s previous exposure to these types of blue light. All 2,000 people involved in the study were breast or prostate cancer patients.

Images from the International Space Station were used by researchers to measure the exposure of these subjects to outdoor artificial light, like streetlights. Everyone taking part in the study answered questionnaires regarding their exposure to the blue light on smartphones and/or tablets. The researchers determined that those exposed to high levels of outdoor blue light had “around a 1.5-fold higher risk of developing breast cancer and a twofold higher risk of developing prostate cancer,” as compared to people who had a considerably lower rate of exposure. The study also says that men exposed to high levels of indoor artificial light run “a 2.8-fold higher risk of developing prostate cancer.”

Alejandro Sanchez de Miguel is the lead author of this study, and a researcher at the Environment and Sustainability Institute at the University of Exeter. He offered the following about the study’s findings.

“The real breakthrough of this study is that, for the first time, we can see directly the color in higher resolution and relate it to individual cases.”

This study is the first to look specifically at blue light, even though previous studies have, in fact, used satellite imagery to calculate the intensity of artificial light at night in metropolitan areas.

“In this study, we focused on the satellite images, because other satellites cannot see the colors,” Sanchez de Miguel said.

Astronauts aboard the space station can see colors, however.

“And so this is the first study to put an experimental value on the correlation between the blue light in the general population with the risk of breast cancer and prostate cancer,” he said.

Exposure to other types of outdoor lighting had no positive association with development of either breast or prostate cancer.

“That finding was unexpected, but it suggests that it is really the blue light that is important for cancer rather than just general brightness,” Kristen Knutson, associate professor of neurology at Northwestern University’s Feinberg School of Medicine said. She was not involved in the study.

Sanchez de Miguel cautions that the study only looked at outdoor blue light, and not the indoor blue light of smartphones and tablets. It shouldn’t be completely ruled out, however.

“That is a confusion for many journalists; we have not done anything in phones,” he said. “But the same mechanism may be affecting the phones or the bulbs at home, because the physiology is the same.”

Richard Stevens is a professor of community medicine and health care at the University of Connecticut. Although he didn’t take part in this study, he notes that a higher color temperature typically correlates with more blue light. He said that some cities have installed new outdoor lighting that emit lower heat, and that they now conform to the original recommendations of the American Medication Association of being no more than 3,000 (Kelvin).

“The utilities put in these lights—I think they were around 4,000 (Kelvin). And about a third of the way through the retrofit, there was pushback from the community,” Stevens explained of Davis, California. “So the city actually sucked it up…and put in much lower-temperature lights.”

NPR recently reported that iPhones feature an app called Night Shift, that filters out blue light from the smartphone.

“I think they’re great,” Stevens said. “They change the spectrum of intensity on the screen depending on time of day, and that’s great. That’s where we need to go in society in general.”

It will be fascinating to learn if other institutions hop on the study bandwagon to further distinguish the dangers of blue light over others in the spectrum. The findings will no doubt determine how LED manufacturers, as well as smartphone and tablet designers, make use of the light.


Leave a Reply