A new study has said that smoking in cars is dangerous for children even when the butt has been thrown out more than an hour ago

Children who ride in such vehicles are in serious danger of developing a number of breathing illnesses.
“Don’t kid yourself that because you cannot see the smoke, it is not there doing harm. Children are still inhaling particulate matter long after cigarettes have been put out”, lead researcher Julie Barratt said before adding that the British government should follow Canada and US’ example by banning smoking inside vehicles.
Source-Medindia