The survey of over 1,500 people found that 65 per cent of non- smokers and 43 per cent of smokers knew that 'third-hand smoke', defined as the tobacco smoke residue which lingers on surfaces, clothes and hair, was harmful.
The researchers said that when people smoke outside, children could still be exposed to tobacco toxins through open windows and doors, and from the smoker exhaling chemicals for several minutes after finishing their cigarette.
They said that health warnings on the dangers of third-hand smoke should be incorporated into current anti-smoking campaigns.
The study said that children are particularly susceptible to third-hand smoke exposure because they breathe, crawl and play around contaminated surfaces, and ingest twice the amount of dust per day as adults.
It added that children with the highest tobacco exposure levels were found to have the lowest reading scores.
Sarah Channon, managing director of the BonBons nursery chain in Bradford, said, 'My son is a severe asthmatic and he was often subjected to the harmful effects of third-hand smoke from staff at his nursery. Our policy at BonBons forbids staff from smoking during breaks which are shorter than 30 minutes, because 15 minutes is not long enough to eliminate the residue left by cigarette smoke on clothes, hair and breath.
'Staff are not allowed to be seen smoking a cigarette while their company uniform is visible and are not permitted to smoke in the vicinity of the buildings. We have found that by making it more difficult for staff to smoke during their working day, it has reduced the numbers who do smoke while at work.'
Further information
'Beliefs about the health effects of third-hand smoke and home smoking bans' is in the January edition of Pediatrics at http://pediatrics.aappublications.org/current.shtml.
