BBC News World EditionAugust 1, 2003Opening a window or wafting away smoke do nothing toreduce children's exposure to tobacco, researchers have found.
Opening a window does not reduce tobacco exposure
Only banning smoking inside the home altogether has any significant effect.
Public health advocates say parents need to be told they can protect their children from the effects of passive smoking, even if they cannot quit altogether.
Researchers from the University of Warwick interviewed parents from 314 households who smoked and had young children.
They were asked what they knew about the effect of tobacco exposure on a child's health, and what they did to minimise that exposure.
Options included opening a window, not smoking in the same room as a child and using a fan or an air freshener.
The scientists then measured levels of cotinine, a by-product of nicotine, in the urine of the children.
Over 80% of parents believed that environmental tobacco smoke is harmful and 90% believed that infants can be protected from it in the home.
Only one in 10 parents did not know any ways to reduce exposure.
More than half tried to reduce exposure in more than one way.
But less than a fifth had banned smoking in the home altogether. This was the only action linked to reduced exposure to tobacco smoke and a significant reduction of cotinine levels.
But less strict measures had no effect, the researchers said, adding that their findings need to be verified in larger studies.
Nick Spencer, professor of child health at the University of Warwick, told BBC News Online: "We were pleasantly surprised that a large proportion of parents were saying that they did take measures to reduce their children's exposure to tobacco smoke.
"But what we were concerned about was the extent to which was the examination of less strict measures, which we're really not sure had an effect.
"It was no different to doing nothing at all."
Professor Spencer said the research showed parents could protect children from the effects of tobacco smoke without giving up cigarettes altogether.
Amanda Sandford, of the campaign group Action on Smoking and Health, said: "We're very encouraged that there was a high awareness of the health risks of passive smoking.
"But the problem is the big gulf between parents' knowledge and actually translating that into behaviour.
"What public health advocates really have to do is increase the level of awareness amongst people, particularly parents, of the dangers of passive smoking."
The research is published in the British Medical Journal.
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Link to Free Full Text of Study
BMJ 2003;327:257 (2 August, 2003)
Effect of strategies to reduce exposure of infants to environmental tobacco smoke in the home: cross sectional survey
Clare Blackburn, senior lecturer,Nick Spencer, professor of child health, Sheila Bonas, lecturer in health psychology, Christine Coe, research fellow, Alan Dolan, lecturer, Rob Moy, senior lecturer in community paediatrics
1 School of Health and Social Studies, University of Warwick, Coventry CV4 7AL, 2 Department of Epidemiology and Public Health, University of Leicester, Leicester LE1 6TP, 3 Institute of Child Health, Birmingham Children's Hospital, Birmingham
Correspondence to: C Blackburn firstname.lastname@example.org
Objective To examine parents' reported knowledge and use of harm reduction strategies to protect their infants from exposure to tobacco smoke in the home, and the relation between reported use of strategies and urinary cotinine to creatinine ratios in the infants.
Design Cross sectional survey.
Settings Coventry and Birmingham.
Main outcome measures Parents' reported knowledge and use of harm reduction strategies and urinary cotinine to creatinine ratios in their infants.
Participants 314 smoking households with infants.
Results 86% of parents (264/307) believed that environmental tobacco smoke is harmful, 90% (281/314) believed that infants can be protected from it in the home, and 10% (32/314) were either unaware of measures or reported using none. 65% of parents (205/314) reported using two or more measures, but only 18% (58/314) reported not allowing smoking in the home. No difference was found in mean log e transformed urinary cotinine to creatinine ratio in infants from households that used no measures compared with households that used less strict measures. Mean log cotinine to creatinine ratios were significantly different in households banning smoking in the home compared with those using less strict or no measures. Banning smoking in the home was independently associated with a significant reduction in urinary cotinine to creatinine ratio by a factor of 2.6 (1.6 to 4.2) after adjustment for average household cigarette consumption, tenure, and overcrowding.
Conclusions Less than a fifth of parents in smoking households ban smoking in the home. Banning smoking was associated with a small but significant reduction in urinary cotinine to creatinine ratio in infants, whereas less strict measures compared with no measures had no effect on the infants' exposure to environmental tobacco smoke.
Link to Above Abstract http://bmj.com/cgi/content/abstract/327/7409/257