Sending or receiving explicit material via smartphones or "sexting" and internet safety have quickly climbed up in the top 10 list of child health concerns in the US, reveals a new study.
Compared with 2014, internet safety rose from the eighth to the fourth biggest problem, ahead of school violence and smoking.
"Sexting" saw the biggest jump, now the sixth top-ranked issue, up from 13th last year in the 2015 annual survey of top children's health concerns conducted by the CS Mott Children's Hospital National Poll on Children's Health.
Childhood obesity, bullying, and drug abuse remained the top three child health concerns for the second year in a row, while child abuse and neglect ranked fifth.
Smoking and tobacco use, usually rated near the top of the list, dropped from the fourth top concern to the seventh - which may reflect the decline in smoking and tobacco use by youth in recent years.
"The major health issues that people are most worried about for children across the country reflect the health initiatives providers, communities and policy makers should be focused on," said Matthew M Davis, director of the National Poll on Children's Health and professor at the University of Michigan Medical School.
The increasing level of concern about Internet safety and "sexting" that are now ranked even higher than smoking as major childhood health issues really dominates the story this year
"We found that while the public may find benefits to today's shifting media environment, whether through cell phones or other technology, many also recognise risks that may make young people vulnerable," Davis noted.
Expanding use of smartphones and other technology potentially exposes children and teens to the danger of predators and other harms like cyber-bullying.
"Sexting" has also led to cases of teenagers around the country suffering from low self-esteem and even committing suicide following photos being widely shared among peers.