BIOLOGICAL MONITORING OF OCCUPATIONAL EXPOSURE TO N-HEXANE BY MEASUREMENT OF URINARY 2,5-HEXANEDIONE

Occupational exposure to n-hexane in shoe factory workers was monitore d by measuring urinary 2,5-hexanedione, the major metabolite of this s olvent and the probable cause of peripheral neuropathy in exposed work ers. Solvent pollution was monitored in the work environments of 189 e mployees, of whom 123 (65%) worked in Alicante, Spain, and 66 (35%) in Veneto, Italy. 2,5-Hexanedione was measured in spot urine samples col lected from workers at the end of the shift. Information on working co nditions was obtained from a previous study. A significant linear corr elation was found between mean environmental concentration of n-hexane and urinary concentration of 2,5-hexanedione. The variability in the correlation may have been due to the variable use of protective clothi ng (gloves), and to variations in exposure during the working week. In numerous workers, percutaneous absorption of n-hexane represented as much as 50% of the total absorbed dose. Urinary concentrations of 2,5- hexanedione tended to increase during the working week. Simultaneous e xposure to n-hexane and toluene tended to reduce urinary excretion of 2,5-hexanedione, whereas exposure to n-hexane and methyl ethyl ketone tended to increase excretion of the metabolite.