Occupational exposure to benzene, toluene and xylene and the lymphocyte lysosomal N-acetyl-beta-D-glucosaminidase.

In 108 workers occupationally exposed to benzene, toluene and xylene the numbers of lymphocytes containing intact lysosomes having cytochemically determined activity of N-acetyl-beta-D-glucosaminidase (NAG) were calculated in the peripheral blood. The benzene, toluene and xylene concentration in the air of at work places were 0-370, 0-580 and 0-506 mg/cu. m, respectively. The phenol concentration in the urine of workers collected between the 6th and the 8th hour of daily work was 16.2 mg/l (SD =9.6). It was stated that one of cytochemical indices of exposure to above compounds was in lowering of numbers of lymphocytes having intact NAG-positive lysosomes. Above phenomenon was noted in subjects having service time longer than 55 months and it was not accompanied by clinical signs of diminished immunity or disturbances in immune skin reactions against such antigens as tuberculin or distrentase.