Dimethylformamide-Induced Liver Damage among Synthetic Leather Workers

Abstract

Prevalence of liver injury associated with dimethylformamide (DMF) exposure was determined. Medical examinations, liver function tests, and creatine phosphokinase (CPK) determinations were performed on 183 of 204 (76%) employees of a synthetic leather factory. Air concentrations of solvents were measured with personal samplers and gas chromatography. The concentration of DMF in air to which each worker was exposed was categorized. High exposure concentrations of DMF (i.e., 25-60 ppm) were significantly associated with elevated alanine aminotransferase (ALT) levels (ALT greater than or equal to 35 IU/l), a result that did not change even after stratification by hepatitis B carrier status. Modeling by logistic regression demonstrated that exposure to high concentrations of DMF was associated with an elevated ALT (p = .01), whereas hepatitis B surface antigen (HBsAg) was slightly but independently associated with an elevated ALT (p = .07). In those workers who had normal ALT values, there occurred still significantly higher mean ALT and aspartate aminotransferase (AST) activities, especially among those who were not HBsAg carriers. A significant association existed between elevated CPK levels and exposure to DMF. However, an analysis of the CPK isoenzyme among 143 workers did not reveal any specific damage to muscles. This outbreak of liver injury among synthetic leather workers is ascribed to DMF. It is recommended that the occupational standard for DMF and its toxicity among HBsAg carriers be evaluated further.

N , N- Dimethylformamide - influence of working conditions and skin penetration on the internal exposure of workers in synthetic textile production

“…The average internal exposure (median) to NMF of all workers exposed to DMF is 7.1 mg/l urine or 4.7 mg/g creatinine. Studies published on the level of external exposure at various workplaces show that exposure to DMF at a level of 10 ppm is usually not exceeded (Brugnone et al 1984;Cai et al 1992;Dixon et al 1983;Max®eld et al 1975;Pozzoli et al 1981;Wang et al 1991;Wicarova and Dadak 1981;Yonemoto and Suzuki, 1980). Casal investigated workplaces producing synthetic leather using personal air sampling and found mean levels of exposure varying between 10 and 20 mg/m 3 air (3.3±6.5 ppm).…”

Liver function alterations in synthetic leather workers exposed to dimethylformamide

“…Other investigators confirmed the absence of liver enzyme abnormalities with low exposures [Catenacci et al, 1980;Tomasini et al, 1983;Imbriani et al, 1986]; Cirla [1984] reported increased g-glutamyl transpeptidase in workers exposed to DMF concentrations of 8-58 mg/m 3 , but no transaminase abnormality. Wang and Lai [1991] reported liver abnormalities in workers chronically exposed to higher air levels of DMF (77-186 mg/m 3 , 25-60 ppm) and, in a longitudinal study of exposed workers with long-term follow-up, Redlich et al [1990] detected both acute and chronic effects of exposure to DMF, with fatty liver changes in individuals exposed for many years and then removed.…”

Occupational Liver Injury Due to N,N-Dimethylformamide in the Synthetics Industry

“…The hepatotoxicity of DMF has been demonstrated in various animal and epidemiological studies (3)(4)(5)(6)(7)(8)(9)(10)(11). The severity of the liver injury is directly related to dose; however, exposure to DMF can cause symptoms even at low concentrations (12 T a b l e 1 .…”