Biological monitoring of workers exposed to N, N-dimethylformamide in synthetic leather manufacturing factories in Korea.
OBJECTIVE
To investigate the relationship between N, N-dimethylformamide (DMF) exposure and excretion of urinary N-acetyl- S-( N-methylcarbamoyl)cysteine (AMCC) and N-methylformamide (NMF) in workers at synthetic leather manufacturing factories in Korea, for the first time.


METHODS
One-hundred forty-four male workers at nine synthetic leather manufacturing factories were surveyed. Exposure to DMF was evaluated through breathing zone air sampling followed by analysis via a gas chromatograph equipped with a flame ionization detector (GC-FID). The levels of NMF and AMCC were determined by a GC with a flame thermionic detector (GC-FTD). Urine samples were collected at the end of the workshift.


CONCLUSIONS
Geometric mean of workplace air DMF and urinary NMF was 8.8 ppm and 47.5 mg/l, respectively, and the level of DMF and NMF was significantly correlated. The biological exposure limit for NMF (15 mg/ml) was exceeded in 89.5% of urine samples, and 37.9% of air samples exceeded the environmental DMF exposure limit (10 ppm), indicating a serious health risk to the employees of the synthetic leather industry in Korea. Exposure to 10 ppm DMF in the workplace air corresponded to a urinary NMF concentration of 53.4 mg/l. Alcohol intake the day before urine was sampled influenced NMF excretion into urine (40.5 mg/l NMF for the no-alcohol group and 94.6 mg/l for the group consuming more than 63.0 g alcohol/day). We could not find a significant relationship between air DMF and urinary AMCC concentration. Exposure to 10 ppm DMF corresponded to an AMCC concentration of 8.0 mg/l in the urine samples collected on the same day as the air was sampled.
Kim
Hyoung-Ah
HA
Department of Preventive Medicine, College of Medicine and Institute of Industrial Medicine, The Catholic University of Korea, Puchon, Gyeonggi-do, Korea.
Kim
Kangyoon
K
Heo
Yong
Y
Lee
Se-Hoon
SH
Choi
Ho-Chun
HC
D000111:Acetylcysteine / Q000031:analogs & derivatives* / Q000652:urine; D000328:Adult; D000395:Air Pollutants, Occupational / Q000633:toxicity*; D000581:Amidohydrolases / Q000633:toxicity* / Q000652:urine; D002849:Chromatography, Gas; D003430:Cross-Sectional Studies; D004784:Environmental Monitoring; D006801:Humans; D007723:Korea; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure; D013783:Textile Industry
D000395:Air Pollutants, Occupational; C052469:N-acetyl-S-(N-methylcarbamoyl)cysteine; D000581:Amidohydrolases; C049646:N,N-dimethylformamidase; D000111:Acetylcysteine