Passive Smoking Linked to Respiratory Problems
LONDON (Reuters) - One of the largest studies of passive smoking found that it increases the risk of asthma and other respiratory problems in non-smokers and is widespread in many countries, particularly in the workplace.
The study, reported in the Lancet medical journal on Friday, analyzed data on nearly 8,000 people in the United States, 16 European countries, Australia and New Zealand.
``It is important to avoid passive smoking and especially passive smoking in workplaces,'' Dr. Christer Janson, an epidemiologist at Akademiska Sjukhuset in Uppsala, Sweden, told Reuters.
The study showed the proportion of people who regard themselves as exposed to passive smoking varied from a high of 53 percent in Spain to less than three percent in Sweden.
Janson said his colleagues analyzed information on nearly 8,000 men and women questioned about their exposure to secondhand smoke and given a physical examination to determine its impact on their health.
In 12 of the 36 centers included in the study more than half of those questioned reported being exposed to secondhand smoke. The prevalence of passive smoking was directly related to the level of smoking in each country.
``The main findings in this investigation of adults who had never smoked are that reported passive smoking was common in all centers,'' the scientists said.
They found passive smoking had a strong effect on asthma and respiratory symptoms such as breathlessness, chest tightness and lung function in adults.
``It (passive smoking) has been described in many other publications in children but it hasn't been studied to that extent in adults,'' said Janson.
The variation among countries also surprised the researchers. Regulations and the prevalence of smoking were the biggest factors determining the number of people exposed to secondhand smoke.
Italy, Spain and other southern and central European countries, which have a higher prevalence of smokers, have more passive smokers while Scandinavian nations, Australia, New Zealand and the United States had the least.
``We found a positive association between passive smoking in the workplace and current asthma,'' the researchers said.
``Decreasing involuntary exposure to tobacco smoke in the community, especially in workplaces, is likely to improve respiratory health.''