CORRELATION BETWEEN CONCENTRATIONS OF N-HEXANE AND TOLUENE IN EXHALEDAND ENVIRONMENTAL AIR IN AN OCCUPATIONALLY EXPOSED POPULATION

We determined the correlations between the concentrations of n-hexane and toluene in exhaled and environmental air in the shoe manufacturing industry. Data were collected in 1988 and in 1992 from a total of 265 subjects. Environmental air samples were collected with personal diff usive samplers by adsorption on activated charcoal during exposure and from end-expired air (alveolar air) on cartridges of activated charco al after exposure. Both compounds were desorbed with carbon disulphide and analysed by gas chromatography. Linear regression analyses showed a good correlation between environmental and end-expired air concentr ations (r = 0.82 for n-hexane and r = 0.81 for toluene). These correla tions allowed us to calculate the concentrations in expired air corres ponding to current environmental limit values. The calculated concentr ations in end-expired air that correspond to current environmental thr eshold limit values of 176 mg m(-3) for n-hexane and 377 mg m(-3) for toluene are 28 mg m(-3) (95% confidence limit, 27-29 mg m(-3)) and 40 mg m(-3)(95% confidence limit, 39-41 mg m(-3)), respectively. Similar correlations were found when the data from the two study periods were analysed separately.