Hematologic Evaluation of Painting Hall Workers in an Automobile Manufacturing Company

Background: Exposure to benzene causes several adverse effects, including decreased number of erythrocytes, leucocytes, and red blood cells, and results in aplastic anemia. The aim of this study was to investigate hematological changes due to benzene exposure in painting workers. Methods: This study was conducted on benzene-exposed and nonexposed workers in Tehran, Iran. The study sample included 40 painters exposed to different levels of benzene and 40 unexposed controls in an automobile manufacturing company. Sampling was carried out with an active pump sampler, using the NIOSH method 1501. Varian C-3800 gas chromatography-flame ionization detector (GC-FID) was used for the analysis of 40 benzene samples. Blood samples from 80 workers were collected from both the case and control groups. Hematological indices were analyzed for red blood cell, white blood cell, hematocrit, hemoglobin, platelet, and white cell differential count. Results: The average amount of benzene in painting workers was 0.775 ± 0.12 ppm. Benzene was not detected in the breathing zone of the control group. Long-term occupational exposure to benzene was lower than 1 ppm. Some blood indices, including the mean corpuscular hemoglobin concentration (MCHC) and eosinophil count, showed significant differences in comparison with the control group (P < 0.05). However, no significant differences were observed in the hematocrit, hemoglobin, mean corpuscular volume (MCV), and MCH of painters, compared to the control group (P > 0.05). Moreover, the platelet count was normal in workers with exposure to benzene. Conclusions: The painters showed evidence of relative exposure to benzene at a concentration below 1 ppm, causing changes in blood cells. The results of this study demonstrated that eosinophils are more sensitive than lymphocytes or neutrophils.