Memory Function and Cell Phone Microwave Exposure in Youngsters - by James C. Lin, University of Illinois at Chicago (2018, IEEE Microwave Magazine) (Unpaywalled)
"Reported results may lead to the conclusion that RF/microwave radiation emitted from GSM cell phones does not produce acute effects on an adolescent’s cognitive or memory function. But available data suggest that significant decreases in figural memory were found to be consistently associated with cumulative exposure of the brain of adolescents to 1,000–4,000 mJ/kg per day over one year. Therefore, a cautious approach to risk management, especially in relation to children and adolescents, is warranted."