This is what they found for brain (glioma) cancer risk:
Mobile phone use > 1 year = 30% increased risk
Cordless phone use > 1 year = 40% increased risk
Mobile phone use > 25 years = 300% increased risk
The risk for brain cancer was greatest in the most exposed part of the brain (side) called the temporal lobe. Notice cordless phones are actually worse than cell phones. They can emit even stronger signals from base to handset.
The scary thing is that children and adolescents are more vulnerable to the effects than adults because of their thinner skull bone and smaller head. The brain is still developing up to about the age of 20 and until that time it is relatively vulnerable. The youngest generation has a very high rate of cellphone use dramatically increasing cancer risk in the future. The study also suggested that the newer "3 and 4G" phone may be more dangerous since they emitted stronger signals.
Some medical authorities still doubt the results since the study used a survey as the method to collect info which has some limitations. However, this study should confirm the potential negative effects of EMF exposure from phones.
A few practical ways to reduce your exposure are:
1) Do hands-free or plug in headphones
2) Text (not while driving) - FYI another study also found that increased smart phone use has increased the amount of time people bend there necks which increases the load on the cervical spine leading to early arthritis in the neck.
3) Turn your phone off or airplane mode while going to bed - the brain is vulnerable while sleeping
Here is the link to the study