The 11th European Congress on Lung Disease and Respiratory Medicine today in Berlin (Germany) provides the first hard evidence, derived mainly from a Finnish report presented in Berlin Monday.
A team working under Maritta Jaakkola, of the Finnish Institute of Occupational Health in Helsinki, studied 718 subjects in the district of Pirkanmaa, southern Finland. Of those, 231 had been diagnosed with asthma in the previous two and a half years, and the remaining 487 represented the control group. None of the subjects had ever smoked.
Comparing exposure to passive smoking by the two groups in the previous twelve months, Jaakkola produced highly telling figures that made for a pioneering presentation to the 11th European Respiratory Society Annual Congress. Subjects exposed to smoke in the workplace were 2.16 times more likely to develop asthma than those who were not exposed. A subject whose partner smoked was 4.77 times more at risk of developing asthma !
"Our results demonstrate conclusively that passive smoking plays a role in the development of adult asthma", stated Jaakkola.
Women suffer the most exposure
In addition to those relative risks, two other studies presented in Berlin revealed that women are particularly affected.
The first was undertaken by Sandra Baldacci, of the Institute of Clinical Physiology in Pisa, Italy, and involved 2,335 non-smoking Italian women drawn from four different areas of the country. The results that she presented to the Congress revealed that 47% of women reported an acute recent exposure (last 7 days) to passive smoking. Considering the lifetime exposure, 63% of women suffered most of the exposure at home and 43% in the workplace.
The link between exposure to others’ smoke and various respiratory dysfunctions varied according to the circumstances; for example, shortness of breath at rest and obstructive lung disease (chronic bronchitis or emphysema) were clearly linked to smoking by the patient’s partner (which multiplied the respective risks by 1.4 and 1.6) and still more strongly linked to smoke in the workplace (which multiplied the risks by 2.1 and 2.3). The respective risks for women who were married to smokers and also worked among smokers were, predictably, even higher at 2.8 and 4.2.
A German study, undertaken by Michaela Kreuzer (BfS-Institute for Radiation Hygiene) and H.-Erich Wichmann (GSF-Institute of Epidemiology), Neuherberg/Munich, on non-smoking female lung cancer patients, also reveals the adverse impact of other people’s smoke.
As Dr. Kreuzer explains to the 11th European Congress on Lung Disease and Respiratory Medicine, her study covered 234 women diagnosed with lung cancer who had never smoked (typically some 20 to 30 per cent of women with lung cancer). They were compared to a control group of 535 women who had smoked no more than 400 cigarettes in their life. Independently of the other risk factors assessed in the study, the relative role of passive smoking at work was found to be beyond doubt, while no clear association of lung cancer and passive smoking at home was observed.
The risk of lung cancer was multiplied by 1.67 for women who had been exposed to their partner’s smoke for a total of more than 76,000 hours, and by 2.67 for those exposed to more than 40,000 hours of passive smoking at work.
Finally, the Berlin Congress heard a number of references to the first results of the large European Community Respiratory Health Survey, involving 36 research centers in 16 countries. One of the aspects it focused on was passive smoking, as described in a poster that was discussed on Monday morning and presented by Christer Janson, of Uppsala University, Sweden.
It indicated that, at 12 of the 36 centres, half of the subjects studied were regularly exposed to passive smoking, particularly in the workplace. While the degree of exposure varied hugely between countries (from only 2% in Uppsala to 54% in Galdakao, Spain), the consequences were no less revealing. In particular, the authors of the Berlin communication pointed to a greater frequency of nocturnal respiratory symptoms, shortness of breath following exertion and excessive bronchial responsiveness.
Logically, Jansen concluded that "decreasing environmental tobacco smoke, particularly in the workplace, is likely to improve respiratory health".