The results of a study done in Japan showed that wives who did not
smoke but were exposed to their husbands' cigarette smoke developed
lung cancer at a much higher rate than those whose husbands did not
smoke. For them, the risk of developing lung cancer was directly
related to the amount their husbands smoked. This was about one-third
of the risk of developing lung cancer taken by smokers.
This study strengthens the thesis that the effect of tobacco smoke on
the non-smoker, which has been called passive, secondhand or
involuntary smoking, may be a cause of lung cancer in the general
population.
The study also strengthens the evidence which implies that passive
smoking is a health hazard. A study published last year suggested that
passive smoking might cause damage to the small airways in the lungs
of non-smokers. Other studies have suggested that passive smoking
may worsen non-smokers' pre-existing chronic heart and lung
conditions.
Lung cancer is a major health problem throughout the world. It is
estimated that in 1997, 122,000 Americans will be told that they have
lung cancer. Moreover, only about 10 per cent of these will live another
five or more years because of the ineffectiveness of available
treatments.
The lungs are the leading sites of cancer in the U.S. among men who
are 35 and over. In women, lung cancer deaths are rising so fast that
experts expect them to exceed breast cancer deaths by the middle of this
decade, becoming the No.l cancer killer of women.
As evidence linking the rise of lung cancer with cigarette smoking
has increased, many experts have theorized that passive smokers have a
greater risk of developing lung cancer than those who are not exposed
to smoke. Such theories are based on the knowledge that second-hand
smoke of cigarettes contains large amounts of toxic substances.
