The way Denmark tracks information about its citizens has made it a unique laboratory for long-term population studies. Taking advantage of this, researchers have found that after adjusting for things like age, years of cellphone use, and income there was no observed link between phone users and cancer. After 15 years of exposure, no dose effect was seen either.
PositiveTip: While these findings are comforting, it is still probably prudent to avoid constant talking on your cellphone unless using some type of earphone.