Original article

Scand J Work Environ Health 1978;4(3):195-203    pdf


Exposure to xylene and ethylbenzene. II. Concentration in subcutaneous adipose tissue

by Engström J, Bjurström R

The amount of body fat in 12 male subjects was determined by means of underwater weighing and anthropometric calculation of skeletal weight. Six subjects (group I) were exposed to 200 ppm of industrial xylene during 30 min of rest and 90 min of exercise at a work load of 50 W. Six subjects (group II) were exposed to 100 ppm for 30 min at rest and during three 3D-min periods of exercise at work loads of 50, 100 and 150 W, respectively. The amount of solvent taken up in the organism was highly correlated to the amount of body fat. When the groups were analyzed together, a correlation was found between the uptake per kilogram of body weight and the alveolar concentrations 4 and 19 h after exposure, even though the groups were exposed under different conditions. However, no correlation was found between total uptake and the alveolar air concentrations after exposure. Needle .biopsies of subcutaneous adipose tissue were taken 0.5, 2, 4 and about 22 h after the end of exposure. Industrial xylene is a mixture of ethylbenzene and 0-, mand p-xylene. The concentrations of ethylbenzene and m- and p-xylene were determined with gas chromatography after evaporation into nitrogen at 150°C. Ortoxylene, which constituted 8.8% of the inspired gas mixture, could not be separated with the column used. Elimination of ethylbenzene-xylene from adipose tissue was slow. The mean concentrations in both groups of subjects were on about the same level after 22 h as during the first 4 h after exposure. In both groups, there was a negative correlation between the concentrations in adipose tissue and the degree of obesity, i.e., obese persons had lower concentrations.

The following article refers to this text: 1979;5(3):217-231