A descriptive and cross sectional study was conducted to determine whether hepatic function changes in workers occupationally exposed to a mixture of organic
solvents, were due to the exposure or confusing factors. A non random sample of 77 workers, operators and supervisors of the
Olefin Plant I and II of a petrochemical industry in Maracaibo, Venezuela, was used. Their mean age was 29 +/- 7 years, and had at least one year of exposure to the
solvents. This sample was compared with a group of employees of the administrative offices or control panel workers, with a mean age of 36 +/- 8 year and with similar anthropometric characteristics. Workers with a known history of
liver disease,
blood transfusions and
diabetes mellitus were excluded of the study. In addition to a complete
occupational disease medical history and a physical examination, serum samples were obtained to determine the activity of the aspartato
aminotransferase (AST), alanin
aminotransferase (ALT), gamma glutamiltransferase (GGT),
alkaline phosphatase (AF), the concentration of the total
bile acids (BAS), the
surface antigen of
hepatitis B(
HbsAg) and the
hepatitis A virus antibodies: AntiHAV-
IgG and the AntiHAV-
IgM. An urine sample was taken and analyzed by standard methodology to determine urinary
phenols. The air concentrations of
benzene,
ethylbenzene,
toluene and
xylene were analyzed by gas chromathography. The serum activities of the liver
enzymes, the concentration of
bile acids and urinary
phenols were not influenced by the exposure to the
solvents. The increase of the activity of GGT was associated with
obesity and alcohol consumption. The
antibodies of the
surface antigen of
hepatitis A-
IgM were normal in both groups and the
antibodies for the
antigen of
hepatitis A-
IgG presented a prevalence of 6% in the exposed group and 9% in the non exposed not being associated with liver abnormalities. The individual air concentrations of the
solvents were below the environmentally permissible concentrations, except one sample of
benzene (1, 14 ppm) that was over the allowed limit. The total maximum concentration of the mixture of organic
solvents, resulting of the sum of fractions of each organic
solvent, was within the allowed limits. In conclusion,
obesity and alcohol consumption, and not the occupational factors, seem to be responsible for the alteration in GGT in workers of these
Olefin Plants.