BIOLOGICAL MONITORING OF N-HEXANE EXPOSURE IN SHOE WORKERS

To analyse working conditions and to provide information about the deg ree to which shoe workers are exposed to n-hexane, the urinary excreti on of total 2,5-hexanedione (2,5-HD) was determined in 81 employees in 12 shoe factories. Twenty-five individuals who had experienced no exp osure to solvents were used as controls. 2,5-HD was measured in spot u rine 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) cr eatinine, a median of 1.96 mg g(-1) creatinine. The mean 2,5-HD concen tration 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 (MIA) concentration of n-hexane in 12 shoe work shops was 126.1 ppm, ranging from 23 to 215 ppm. We found a significan t, but low, correlation (r = 0.40; p < 0.001) between MIA 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.