Researchers say there is an urgent need for action after 95 per cent of children from 12 primary schools in Dhaka tested positive for recent second-hand smoke (SHS) exposure.
The study, which involved collaboration with the University of Dhaka, is the first to report on biochemically validated second hand smoke exposure among children in a low and middle-income country (LMIC).
The Dhaka results are more than double of those expected globally (40 %) and in stark contrast with those reported in the UK (31%) and in Canada (9.2%) which have comprehensive smoke-free legislation.
Lead author Sarwat Shah, a research fellow in the Department of Health Sciences at York, said the results were alarming.
She said: "Despite having a ban on smoking in public places, the results of the study reveal recent second-hand smoke exposure among children in Bangladesh remains very high.
"Children bear the biggest burden of disease due to second-hand smoke and face increased risk of respiratory tract infections, allergies and asthma.
"There is an urgent need to reduce exposure to second-hand smoke in Bangladeshi children.
"Children have little control over their environment, they are dependent on others to introduce measures to protect them from SHS exposure."
The research team say the next step is to engage with policy makers and devise a framework which enforces smoke-free laws and interventions to reduce exposure of children to second-hand smoke in the home.
As part of the survey, nearly 500 children aged 9-12 provided saliva samples for testing. Overall 95 per cent were found to have recent exposure to SHS. Of all the participants, 43 per cent reported living with a smoker.
The results are published in the journal Nicotine & Tobacco Research and the study was funded by the Medical Research Council.