Before its announcement Tuesday, WHO had assured consumers that no adverse health effects had been established.
A team of 31 scientists from 14 countries, including the United States, made the decision after reviewing peer-reviewed studies on cell phone safety. The team found enough evidence to categorize personal exposure as "possibly carcinogenic to humans."
What that means is they found some evidence of increase in glioma and acoustic neuroma brain cancer for mobile phone users, but have not been able to draw conclusions for other types of cancers
"The biggest problem we have is that we know most environmental factors take several decades of exposure before we really see the consequences," said Dr. Keith Black, chairman of neurology at Cedars-Sinai Medical Center in Los Angeles.