However, for lighter users, rates of adverse health measures were no greater than for nonusers In a new study of more than 50,000 Korean adolescents, those who used a smartphone for more than 4 hours per day had higher rates …
However, for lighter users, rates of adverse health measures were no greater than for nonusers In a new study of more than 50,000 Korean adolescents, those who used a smartphone for more than 4 hours per day had higher rates …