[Effects of cigarette smoking on blood and alveolar air levels of benzene].

Benzene was measured in blood and alveolar air of a group of 168 subjects, consisting of 34 chemical industry workers exposed to benzene and 134 definitely not occupationally exposed to benzene. A gas chromatographic method was used with mass spectrometry and cryogenic trap. The results of the biological measurements were compared with the environmental levels of benzene in the room where samples were taken and at the worksite during the previous day's shift. All environmental air samples showed measurable levels of benzene, which agrees with the observations of many authors, according to which benzene is a common pollutant also of the living and external environments. Benzene in blood measured on morning samples was correlated with the previous day's exposure. In the group of non-exposed, both blood and alveolar concentrations of benzene were significantly higher in the 68 smokers than in the 66 non-smokers and the biological levels of benzene were inversely correlated with the time that had elapsed since the last cigarette smoked. In the chemical workers, the high biological levels of benzene due to occupational exposure largely exceeded the variations in concentration due to cigarette smoking and cancelled out the differences between smokers and non-smokers. It can therefore be assumed that smoking was not influential and did not interfere with the interpretation of the results in the occupationally exposed workers. Lastly, cigarette smoking, as a cyclical and additional factors of exposure, seems to be responsible for the disturbance in the relationships between biological benzene levels and ubiquitous environmental pollution, a relationship that was only observable in non-smoking subjects not occupationally exposed, but not in the group of smokers.