REDUCTION OF WORKER EXPOSURE TO SOLVENTS BY MEANS OF AN OCCUPATIONAL HEALTH PROGRAM: AN EXPERIENCE AT A SYNTHETIC LEATHER FACTORY IN TAIWAN

Objective-To assess the effects of an occupational health program which was to reduce synthetic leather workers' exposure to solvents (N,N-dimethylformamide (DMF), epichlorohydrin (ECH) and toluene). Methods-Worker exposure to these airborne solvents was measured in 1999 and compared with results obtained in 1997. Due to high solvent levels in the workplace, an occupational health program was implemented in 1997 to reduce worker exposure to solvents. Biological monitoring was conducted by measuring workers' urinary DMF, NMF (N-methylformamide) and formamide concentrations, and the factors influencing these indicators were investigated. NMF levels obtained in 1997 were compared with levels in 1999. Results-Airborne DMF, ECH and toluene concentrations were significantly reduced in all three workstations in the 1999 study (compared to the 1997 study). In 1997, the urinary NMF concentration was 3.31 mg/g cre. compared to 2.13 mg/g cre. in 1999, which represented a 35.6% decrease. Urinary DMF and formamide concentrations were 0.42 and 1.24 mg/g cre., respectively, in 1999. There was a positive correlation between urinary NMF concentration and environmental DMF (r=0.49 for area sampling, r=0.55 for personal sampling). For biological monitoring, the urinary NMF concentration was significantly correlated with formamide (r=0.79) and parent DMF (r=0.33). Multiple regressions showed that the factors affecting the concentration of the biological indicators (NMF, DMF and formamide) in urine were: airborne DMF concentration, duration of worker employment and alcohol consumption. Conclusion-The occupational health program implemented in 1997 was effective in quickly reducing airborne solvents, but urinary NMF levels were not as responsive.