Children exposed to passive smoking at risk of long-term lung problemsResearchers found a strong link between childhood exposure to second-hand smoke and chronic cough in adulthood
09:58 GMT, 21 May 2012
Children who are exposed to secondhand smoke may experience the damaging effects well into adulthood, say scientists.
Researchers found even non-smokers who were exposed to passive smoking when they were young had a higher risk of developing chornic chest infections.
The team from the University of Arizona analysed results from a 24-year study that assessed the prevalence rates and risk factors of respiratory and other chronic diseases.
Smoking increases a child's risk of developing chronic bronchitis as adults
Participants were asked to complete questionnaires that were issued every two years from 1972 until 1996. The researchers found that 52.3 per cent of the children had been exposed to tobacco smoke between birth and 15 years old.
After adjusting for sex, age, years of follow-up and personal smoking status, the researchers found that this exposure was significantly associated with several persistent respiratory symptoms.
Study author Dr Juliana Pugmire, said: 'We examined asthma as well as other respiratory symptoms and found that exposure to parental smoking had the strongest association with cough and chronic cough that persisted into adult life.
'Exposure to parental smoking also had effects, although weaker, on persistent wheezing and asthma in adulthood.'
While researchers have warned of the potential health risks of second-hand smoke for 30 years, there have been few studies into the long-term effects on children.
'Earlier studies established a link between parental smoking and childhood respiratory illness, but in this study, we sought to demonstrate whether these effects persisted into adulthood,' she said.
Dr Pugmire said that wheezing and a chronic cough were early risk factors of far more serious lung conditions.
'Persistent wheezing from childhood into adult life has been shown to be associated with lung function deficits.
'Chronic bronchitis (defined as chronic cough and phlegm) is a significant risk factor for chronic obstructive pulmonary disease (COPD) development later in life.
'Therefore, the persistence of symptoms like chronic cough and wheeze into young adulthood may indicate a susceptibility to lung function deficits and chronic respiratory illness with age,' she said.
Further research will be needed to examine whether smokers who were exposed to second-hand smoke as children have a greater risk of dying in middle-age than smokers who were not exposed, she added.
The study will be presented at the ATS 2012 International Conference in San Francisco.