Just as second hand smoking is harmful to children, so is 'Passive TV' which could retard their language development. Poor language development in turn makes it difficult for children to cope in school, say experts.
The American Academy of Paediatrics warns about 'secondhand television' in its guidelines for children aged under two.
The AAP report said TV deterred children and parents from interacting, which it said was crucial to vocabulary development.
"When parents are watching their own programmes, this is 'background media' for their children,'" the Daily Mail quoted the report as stating.
"It distracts the parent and decreases parent-child interaction. Its presence may also interfere with a young child's learning from play," it added.
Experts said parents needed to understand that 'their own media use can have a negative effect on children."
Experts suggested that so-called 'unstructured' free playtime is more valuable for the developing brain than electronic media.
"If you're trying to connect with your kids, you've got to turn the screens off," said Ari Brown, a Texas paediatrician who led the AAP's new research.