Mobile Phone Light Linked with Colon Cancer: Are Toxins in LED Lights to Blame?

Scientists conducting a new research study have just released some disturbing results: Exposure to mobile phone light at night raises risk of colon (bowel) cancer.  The study revealed that LED “blue light” emitted by our electronic devices (that is, exposure to artificial light-at-night (ALAN) and particularly blue light spectrum) can worsen health problems–including increasing the risk for colon cancer by as much as 60 percent*. 

There are some theories floating around in the scientific community now to explain possible reasons for why the light from electronic devices (including mobile phones and tablets) is linked to such serious health outcomes.  Among the theories is that exposure to the “blue light” at nighttime suppresses melatonin levels in the body, thereby creating hormonal imbalance and leaving us susceptible to a number of serious health outcomes including insomnia, obesity and colon cancer. Some experts suggest the blue light from our phones and other devices may disrupt the body’s circadian rhythm, which in turn affects hormone levels. Both breast and prostate cancers are hormone-related. Previous studies have indicated links between LED lighting and breast and prostate cancer.

But is something else also going on?  We know from studies dating as far back as a decade ago that the LED lighting (or light-emitting diodes) used in tech devices (and a growing number of interior lamps and lighting fixtures for homes in the U.S.) has a dark side. Namely, LEDs contain lead, arsenic and a dozen other potentially dangerous substances.  Lead and arsenic are known carcinogenic substances. And, while tests of LED lights have indicated that the white lights commonly used for interior home lighting contain lower levels of lead than say, the light used in your car taillights, they are still toxic and still hold risks. If you break one of these puppies inside your home for instance, the protocol is to use protective masks, gloves and a broom to clean up the hazardous material and then throw everything out–including the broom. The lead scientist of a study published in Environmental Science and Technology focusing on  the toxins in LED lights has said, “while breaking open a single LED light and breathing in its fumes wouldn’t likely cause cancer, our bodies hardly need more toxic substances floating around, as the combined effects could be a disease trigger.”

Given that LED lights contain varying levels of toxic substances, and given that the LED “blue light” present in our devices is contained in housing that heats up, and, unlike the light bulbs in our bedroom lamps, is frequently held close to our faces (possibly even more so when using tablets and phones at nighttime), is it possible that fumes from one or more of the several toxins present in these lights are seeping out, exposing consumers to elevated risks for cancer and other serious health conditions?  It is a question that may merit consideration–and more than one scientific investigation.


*Study Results: Exposure to blue light spectrum was positively associated with colorectal cancer (OR = 1.6; 95% CI: 1.2–2.2; highest vs. lowest tertile). ORs were similar (OR = 1.7; 95% CI: 1.3–2.3) when further adjusting for area socioeconomic status, diet patterns, smoking, sleep, and family history.  We observed no association for outdoor visual light (full spectrum) (OR = 1.0; 95% CI, 0.7–1.2; highest vs. lowest tertile).  Conclusion of researchers: blue light spectrum exposure that is increasingly prevalent in recent years may be associated with colorectal cancer risk. 

Journal Reference:  Garcia-Saenz, A., et al., Association Between Outdoor Light-at-night Exposure and Colorectal Cancer in Spain, Epidemiology Journal, September 2020 – Volume 31 – Issue 5 – p 718-727.  doi: 10.1097/EDE.0000000000001226

Video abstract:; Overview; Scientific American synopsis on The Dark Side of LED Light bulbs