Many people were confused about cell phone safety after seeing headlines about a memo issued by a prominent cancer expert recommending limiting cell phone use, especially in kids, because of possible cancer risk.
That scientist recommends that children use cell phones only in emergencies because their brains are still developing and that adults should keep cell phones away from their head by using the speakerphone or wireless headset.

The FDA and the American cancer society agree that the available evidence does not show that any health problems are associated with using wireless phones. And also that there is no proof, however, that wireless phones are absolutely safe The FDA adds that wireless phones emit low levels of radiofrequency (RF) while being use and exposure to those (RF) does not causes any known adverse health effects as these radiations aren’t ionizing radiation that could damage DNA"

The American Academy of Pediatrics doesn't have an official stance on kids' cell phone use "There is no established cancer risk in children from cell phones, nor in adults," there is really no compelling evidence there whatsoever that cell phones are associated with brain tumors or other tumors in children

Parents should be reassured that there is no established risk, and they should feel good about the choices they make for their children."
Should parents limit kids' cell phone use?
There is good reason to limit kids' cell phone use (out of good parenting and parental choice rather than health hazards)

As the kids can get distracted easily by cell phones it is advised:
1. To restrict your kids' use of cell phones.
2. Not to sit in bed and talk on cell phones at night.
3. Kids shouldn’t be allowed to use cell phone before the age of 8 years.
4. Kids shouldn’t be given unrestrained access 24-7 to cell phones.
These restrictions shouldn't be done because of paranoia or fear of perceived risks that aren't established.

Conclusion
No studies have proven that cell phones cause brain cancer or other health problems. But none has ruled out health risks once and for all, either. Yet children should be using cell phones only in emergencies because it’s better to be "safe rather than sorry later,"