Chances are, when you walk down the street, take public transportation, or are waiting in line at the grocery store, more than half the people you see will be on their smartphones. As we have 24/7 access to the world at our finger tips, we can’t seem to look up for more than five seconds before we stare back down at our phones. However, according to a recent study published in the journal British Occupational and Environmental Medicine, it may be time to kick your cell phone habit to the curb. Using your smartphone for more than 15 hours plus a month can triple your brain cancer risk just over a span of five years.

This new report from French scientists comes after an extensive 11-year report found there is no link between mobile phone usage and cancer. Although the previous study did not establish a link between the two, scientists like Isabelle Baldi, author of the French study, believe a risk does exist because cell phones emit radiofrequency energy — a form of non-ionzing electromagnetic radiation — thought to be a carcinogen. This form of energy can be absorbed by tissues closest to where the phone is held, says the National Cancer Institute, questioning mobile phone safety.

"It is difficult to define a level of risk, if any, especially as mobile phone technology is constantly evolving," wrote the team of French scientists at the University of Bordeux in south-western France, according to Medical Xpress. This holds especially true since investigations over the last 15 years have failed to turn up conclusive results regarding cellphone use and cancer risk. However, these studies include clear proof that these radiofrequency fields are harmful to human cells.

To observe the link between glioma and meningioma — types of brain tumors — and heavy cellphone use, Baldi and her colleagues looked at over 250 cases of glioma, and almost 200 cases of meningioma reported in four French departments between 2004 and 2006. Glioma is the general term used to describe any tumor that forms from the supportive tissue of the brain, known as the glia, which helps keep the neurons in place and functioning normally. Unlike glioma, meningioma arises from the coverings of the brain and spinal cord, and do not grow from brain tissue. The participants of the study were matched against about 900 healthy individuals drawn from the general population, to be used as a comparison to spot any differences between the two groups.

The findings revealed those who used their phones frequently, especially among those who used it for work, such as in sales, faced a higher risk of developing these tumors within five years of use. Moreover, the researchers discovered contrary to previous research, cancer occurred on the opposite side of the brain, rather than on the same side where the phone is customarily used. However, the French scientists caution that further research is needed to investigate the potential long-term effects of heavy cell phone use.

One of the main difficulties in establishing a possible link is assessing phone use in real life by accounting for other cancer-causing behaviors, such as smoking. Also, the evolution of cell phone technology, has made it difficult for researchers to form conclusive findings. "The rapid evolution of technology has led to a considerable increase in the use of mobile phones and a parallel decrease of [radiowave intensity] emitted by the phones,” wrote the authors of the study.

In 2011, the International Agency for Research on Cancer (IARC), acknowledged radiofrequency fields used by mobile phones were possibly carcinogenic, which therefore suggests there could be some risk. As the number of mobile phone subscriptions continues to rise — estimated at five billion globally — this becomes of particular concern regarding public health, since one of the biggest group of users are young adults and children.

Roger Salamon, director of university institute ISPED, suggests, “There is no reason to panic. This does not mean that everyone who makes a call with a mobile phone is going to get a brain tumor.”

 

Source: Baldi I, Bouvier G, Coureau G, et al. Mobile phone use and brain tumours in the CERENAT case-control study. British Occupational and Environmental Medicine. 2014.