Biological monitoring of n-hexane exposure in shoe workers

Abstract

To analyse working conditions and to provide information about the degree to which shoe workers are exposed to n-hexane, the urinary excretion of total 2,5-hexanedione (2,5-HD) was determined in 81 employees in 12 shoe factories. Twenty-five individuals who had experienced no exposure to solvents were used as controls. 2,5-HD was measured in spot urine samples collected from workers at the end of shift. In the urine of shoe workers, the 2,5-HD presented a mean value of 2.33 mg g^-1 creatinine, a median of 1.96 mg g^-1 creatinine. The mean 2,5-HD concentration in the urine samples from non-exposed subjects was 0.28 mg g^-1 creatinine, the median value was 0.18 mg g^-1 creatinine. The mean time-weighted average (TWA) concentration of n-hexane in 12 shoe workshops was 126.1 ppm, ranging from 23 to 215 ppm. We found a significant, but low, correlation (r = 0.40; p < 0.001) between TWA intensity of environmental exposure to n-hexane and the concentration of 2,5-HD in urine. The probable effect of toluene on the concentration of 2,5-HD was also discussed in the present study.

Keywords::

• n-hexane, 2,5-hexanedione, urine, biological monitoring