[The exposure to tobacco smoke of the employees of a telephone company].

Smoking habits were studied in a group of employees of a telephone company. The smokers were 34% of the subjects interviewed. The non-smokers said that they were bothered by other people smoking everywhere and also to a considerable extent at the workplace. Differences between smokers and non-smokers and between exposed and non-exposed non-smokers were studied by measuring expired CO and urinary cotinine. An expired CO concentration of 10 ppm discriminated between smokers and non-smokers. A mean urinary cotinine concentration of about 16 ng/mg was found in the exposed non-smokers, corresponding to the direct smoking of 1/10 of a cigarette per day. The search for the metabolic phenotype of destromethorphane, which was taken as an indicator of susceptibility to contract lung cancer due to IPA, showed that there were no differences between smokers and non-smokers since the rapid metabolizers, and therefore subjects potentially exposed to risk of lung cancer due to tobacco smoke, prevailed in both groups.