The problem is that it is VERY hard to do a conclusive study on this. Never mind that a low dose radiation study would take many years: the hard part is that you need to randomly select half of your group to use only non-radiating (non-functional) cell phones. Good luck finding a group of volunteers for that.
Following your link:
> In 2011, International Agency for Research on Cancer (IARC) classified mobile phone radiation as Group 2B - possibly carcinogenic.
Group 2B includes coffee, pickled vegetables, titanium dioxide (used in food coloring and sunscreens), and work in carpentry, dry cleaning, printing industry, and textile industry.
I think I'll keep my cell phone. (And coffee and kimchi, for that matter.)