When it comes to the link between cell phones and cancer, studies have shown mixed results. However, new research carried out by Environmental Health Perspectives has shown that the blue light exposure from phones and tablets could increase the risk of breast or prostate cancer. The study looked at the level of exposure to artificial LED lights at night in 2000 cancer patients and 2000 individuals without cancer.
The researchers measures the participants exposure to outdoor artificial lights using images from the International Space Station. They also looked at exposure to indoor artificial lighting by using a self reported questionnaire. It was found that those patients who were exposed to high levels of artificial blue light were at a 1.5% higher risk of developing breast cancer.
For prostate cancer, the risk was twice as high when compared to individuals who were less exposed to artificial lights. For exposure to indoor artificial light, the risks were even higher. The participants who were exposed to high levels of indoor artificial light were at a 2.8% higher risk of developing prostate cancer.
Alejandro Sánchez de Miguel, a researcher at the Environment and Sustainability Institute at the University of Exeter and a lead author on the study said: “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.”
“In this study, we focused on the satellite images, because other satellites cannot see the colors. And so this is the first study to put an experimental value on the correlation between blue light in the general population with the risk of breast cancer and prostate cancer.”
Blue light has a shorter wavelength than other light of the spectrum. Therefore, it produces more energy, and prolonged exposure can cause the release of melatonin in the brain to slow, causing problems with the body’s ability to regulate circadian rhythm.
Kristen Knutson, associate professor of neurology at Northwestern University’s Feinberg School of Medicine, who was not involved in the new study said: “That finding was unexpected but suggests that it is really the blue light that is important for cancer rather than just general brightness of light.”
“Blue light is the spectrum that signals the clock in the brain, and it is the spectrum that suppresses melatonin. Melatonin is a hormone that plays an important role in maintaining the synchronization of the clocks in all our body’s cells. Disruption of these clocks is thought to increase the risk of cancer.”
Although this study only looked at the effect of blue light from outdoor LEDs, blue light is also produced in smartphones and tablets, which could be affecting our risks of cancer. “That is a confusion for many journalists; we have not done anything in phones. But the same mechanism may be affecting the phones or the bulbs at home, because the physiology is the same,” said Sánchez de Miguel.