Your neighbours smoke on their balcony, or you have a smoking grandparent living in a house with a child. What are the risks?
According to the American health authorities, there is no safe distance for those close to a lit cigarette. If you can smell cigarette smoke, then you are subjected to up to 7000 toxic chemicals in that smoke.
The American company Inogen, which makes oxygen concentrators for people with impaired lung function, conducted an outdoor experiment with a particle counter. The experiment showed that the concentration of harmful particles does reduce with distance, but remained 46% higher than base level even when a cigarette was 8 metres away.
Passive smoking certainly increases the risk of cancer, as demonstrated by a major analysis from 2018 based on 40 studies. The analysis also showed that the effect is higher in women than men, increasing the risk of both breast and lung cancer. And passive smoking by pregnant women is linked with low baby birth weight.
People with cardiac or lung diseases can develop more severe symptoms due to passive smoking; it has also been linked with a higher risk of stroke, particularly among nonsmokers who are regularly subjected to other people’s smoke.
Cigarette smoke is particularly harmful to children, because they inhale more air per kilogram of body weight than adults, and to elderly people, because their health and immune systems are generally weaker.