[Prospective examinations concerning the effect of exposure to aromatic hydrocarbons on health status]

The purpose of the study was to evaluate the general and toxicological status of footwear factory workers exposed to toluene, benzene and trace amounts of chromium. The subjects were 80 persons who worked with the glue, and were professionally exposed to aromatic hydrocarbons such as toluene and benzene AT amounts not exceeding the TLVs. The mean age of the subjects was 46.89 years and the mean period of work 20.26 years. Complete internal and neurological examinations were carried out. The following parameters were determined: hematocrit, hemoglobin, erythrocytes, leukocytes, platelets, reticulocytes, chromium, copper, zinc in serum and hippuric acid in urine (in 30 persons). In the examined group no changes in the leukocyte system were found. Two women had a lower hemoglobin level and erythrocyte count. In three persons thrombocytopenia was observed (3.75%). The mean metal levels in serum were within normal values. Only in 4 persons (5.0%) elevated levels of phenol in urine were found which indicated exposure to benzene. In 30 subjects (18 women and 12 men) (most exposed to toluene) the hippuric acid level in urine was examined. It was found to range from 130 mg/l to 2080 mg/l. In the control group not exposed to either of the solvents the level of hippuric acid in urine varied from 190 to 330 mg/l. There was little effect of aromatic hydrocarbons on hematopoiesis. The increased absorption of benzene or toluene found in the examined persons would indicate a necessity for biological monitoring of this group.