Exposure to environmental tobacco smoke (ETS) or passive smoking is an important risk factor like active smoking, but to a lesser extent.

Passive smoking is important in people who work in smoke filled atmospheres, such as bars and casinos.

We used the test to measure exposure to ETS in bar staff (Ann Clin Biochem 2000).

The test results showed nicotine intake increased in subjects after a 6-hour shift in a smoky pub, depending on the area in which they were working.

Measurements were also related to the extent of reduced respiratory function and to salivary antioxidant status.

From an investigation into passive smoking in children with asthma, the results suggested that the severity of asthma suffered by the child was related to their exposure to passive smoking. These results were related to the number of smokers in the household, and the cumulative number of cigarettes smoked.

A similar study in children with cystic fibrosis showed that bacterial lung infections were related to the level of exposure to parental smoking.