In a study of a total of 25,930 children-
The average wearing time of the mask was 270 minutes per day. Impairments caused by wearing the mask were reported by 68% of the parents. These included irritability (60%), headache (53%), difficulty concentrating (50%), less happiness (49%), reluctance to go to school/kindergarten (44%), malaise (42%) impaired learning (38%) and drowsiness or fatigue (37%).
https://www.researchsquare.com/article/rs-124394/v2
Corona children studies "Co-Ki": First results of a Germany-wide registry on mouth and nose covering (mask) in children | Research Square
Background: Narratives about complaints in children and adolescents caused by wearing a mask are accumulating. There is, to date, no registry for side effects of masks.Methods: At the University of Witten/Herdecke an online registry has been set up wher...
https://www.researchsquare.com/article/rs-124394/v2