The team was led by Joel Moskowitz, director of the Center for Family and Community Health at the UC Berkeley School of Public Health. They conducted their research in partnership with Seoul National University and the National Cancer Center of South Korea. The study was published in the International Journal of Environmental Research and Public Health.
Moskowitz and his team conducted a meta-analysis of case-control studies from 16 different countries, including the United States, the United Kingdom, Japan and South Korea. Based on data reported by 45 studies, they concluded that cell phone use with a cumulative call time of more than 1,000 hours -- about 17 minutes per day over a period of 10 years -- is associated with a 60 percent increased risk of developing tumors. In particular, they found that brain tumors and head and neck cancer accounted for most of the tumors linked to cell phone use.
However, Moskowitz and his team acknowledged that more comprehensive research is necessary.
"Further quality prospective studies providing higher level of evidence than case-control studies are warranted to confirm our findings," wrote the researchers.
Cell phone use has become part of many people's daily lives, thanks to the emergence of smartphones, which have made life much easier in many ways. Over the years, cell phones have become the primary means of communication in the United States. Recent figures from the Pew Research Center show that 97 percent of Americans own some kind of cell phone.
Furthermore, an increasing number of Americans have given up the use of landlines in favor of having cell phones as their sole means of communication. Data from the National Center for Health Statistics show that nearly 62 percent of adults are now wireless-only.
But reports have emerged highlighting a potential link between cell phone use and serious health problems, particularly cancer. Moskowitz has been sounding the alarm for more than a decade now.
"Cell phone use highlights a host of public health issues and it has received little attention in the scientific community, unfortunately," said Moskowitz.
In an interview with UC Berkeley's official news outlet, Moskowitz said he believes the influence of the telecommunications industry is preventing lawmakers and the Federal Communications Commission from conducting additional research to investigate the link between cell phone radiation and cancer.
Many of the studies that looked into the health risks associated with cell phone use have been funded by the cell phone industry, so their findings were in favor of continued cell phone use. Critics like Moskowitz have denounced these studies because they skew research results.
Moskowitz has likened the tactics employed by the Cellular Telecommunications and Internet Association (CTIA) to those used by the tobacco industry for decades to conceal the health risks associated with cigarettes.
"In the 1940s, tobacco companies hired doctors and dentists to endorse their products to reduce public health concerns about smoking risks. The CTIA currently uses a nuclear physicist from academia to assure policymakers that microwave radiation is safe. The telecom industry not only uses the tobacco industry playbook. It is more economically and politically powerful than Big Tobacco ever was," said Moskowitz. (Related: Listen up, iPhone users: Apple smartphones are emitting TWICE the reported radiofrequency radiation.)
To avoid too much radiation exposure, experts suggest putting phones in airplane mode when not in use. When on a call, use the speaker feature or a headset instead of holding the phone up to your head.
Health officials also advise against using phones when their battery is running out. They said cell phones emit more potentially cancer-causing radiofrequency energy to connect with cell towers when their batteries are low.
"Distance is your friend," said Moskowitz. "Keeping your cell phone 10 inches away from your body, as compared to one-tenth of an inch, results in a 10,000-fold reduction in exposure. So, keep your phone away from your head and body."
Learn more about how cell phones can cause cancer at Radiation.news.