T and B cells and occupational exposure to benzene and its homologues (with regard to other blood cells).

In 106 workers (47 women and 59 men) having occupational contact with organic solvents containing benzene and its homologues during 1 to 122 months the quantitative evaluation of the white blood cell and the platelet system has been performed. In workers having longer time of service than 55 months the decreased T and the "non-T, non-B" lymphocyte count as well as increased counts of monocytes in the peripheral blood have been stated. Furthermore, the negative correlation between the T cell numbers and the exposure time has been stated what indicates the practical value of the E rosette test in evaluation of early biological effects of occupational exposure to solvents containing benzene, toluene and xylene. According to the authors' opinion a depressive effect of benzene and its homologues on the T cell-dependent immunity suggests an alternative mechanism of cancerogenic activity of that compounds via the immune system. The toxic effect of organic solvents containing benzene and its homologues on blood forming organs is among other reflected in quantitative alterations of the white blood cells and the platelet systems (6, 17). In workers occupationally exposed to benzene, toluene and xylene neutropenia (1, 2, 6, 17), eosinophilia (2), basophilia (2), monocytosis (14) and both lymphocytosis and lymphocytopenia (3, 14) has been observed. The occupational contact with above compounds may also results in thrombocytopenia (11, 12) or qualitative changes in platelets resembling that noted in patients with the Glanzman thrombasthenia (4).