Since the hepatotoxic role of
toluene in exposed workers from the
petroleum and petrochemical industries chronically exposed to low concentration has no been entirely dilucidated, this transversal study was undertaken in order to clarify the situation in the local industries. A group of 33 non-exposed men workers of such industries (group control, aged 33.0 +/- 4.88 years) were compared with 33
toluene-exposed men (aged 35.0 +/- 9.33 years) from the related industries, with a minimal of 6 months exposition time to
toluene and without
liver disease history. In addition to a complete
occupational diseases medical history, each subject was tested by both a venous blood sample (to determine
prothrombin, total and fractioned
bilirubin, total and fractioned
proteins, liver
enzymes and
cholesterol) and urine sample (
hippuric acid). Also the environmental concentration of
toluene in working areas was determined by gas chromatography, which was below the recommended standard levels in working areas. Although the analyzed parameters were in the normal range, it was observed that those workers with known alcohol ingestion and
toluene exposition had several abnormalities. The results of this study confirm that
toluene may have a synergistic hepatotoxic effect in
toluene-exposed workers that are alcohol consumers. The alcohol in considered as a confounding factor and it is not possible to rule out in the etiology of hepatic changes detected in the study.